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1. 94 L ACOUSTICS V DOSC Manual Version 3 2 10 01 5 119 6 1 RECOMMENDED MAINTENANCE 94 6 2 RECOMMENDED MAINTENANCE TOQOLS 94 6 3 SPARE FAR 95 6 4 RECOMMENDED INSTALLATION TOQOLS 5 5 5 trt en diane nae eas 96 T SPECIFICATIONS 2225225 SEHR EEE 97 V DOSG ELEMENT SPECIFICATIONS a u aS Sia 97 7 2 SB218 SUBWOOFER SPECIFICATIOINS use een 99 73 FLYING STRUCTURES ee 100 V DOSG Flying Bumper anne een 100 p SB 218 Flymo aus ne ee aO kawaka 10 146024 INE ASSIGNMENT SUMMARY a ua aaa aan eu 102 7 5 CO24 CONTROL OUTPUT PANEL LINE ASSIGNAMENTTS 103 7 6 MD24 MULTIDISTRO PANEL LINE ASSIGNAMENTS 105 7 7 APPROVED AMPLIFIER 2 107 LACOUSTIES LA uu uuu Re 107 BIEROWNIMASOOOVZ Eee 107 Bab Gr pperi 4000 u y Qu dd 107 APPENDIX 1 WHY DO SEPARATED SOUND SOURCES INTERFERE 108 APPENDIX 2 FURTHER EXPLANATIONS REGARDING WST
2. 27 Fle re 9 SB218 Flfine Bar an 28 Figure 10 L ACOUSTICS Amplifier Rack L D u uu si eene entente nnne 29 Figure V POSCAMR Panels haapa utan 30 Figure 12 V DOSC CO24 CONTROL OUTPUT Panel 42 Figure 132 V DPOSEMD2 MULTI_DISTIRO ces 44 Figure 14 Horizontal V DOSC isocontour averaged from 630 Hz 16 kHZz 46 Figure 15 Horizontal V DOSC isocontour averaged from 32 Hz 630 Hz 46 Figure 16 Constant Curvature Array Examples 49 Figure 17 Defining Cutview Dimensions u uuu ie 50 Figure 18 Parameters for the ROOM DIM Utility Sheet in ARRAY 5 Figure 19 Optimizing Array Element Focus By Adjusting For Equal Spacing 52 Figure 20 Physical Rigging Parameters for ARRAY 53 Figure 21 ARRAY spreadsheet calculation example 56 Figure 22 Illustration of Stacking Guidelines
3. 8158165 _ Wrws IHXGA IH OSOA O T SOTA 2 8058185 2 7 DTX A L ee e e ee SN amos 9 no Gamogs no IND amo tino ZING amos SIN 54135344 1080 9A NOISHHA 99 SQ 558 BSS FDS 366 Presets Table 7 39 119 10 01 L ACOUSTICS V DOSC Manual Version 3 2 XTA DP224 VERSION 6 0801 PRESETS FOR V DOSC 90581795 IH WASI IH WAS 9 ans ANS AP 8 ans ans Ap ans 81295 8 15 81295 YY SOWV Puro 8 795 Puro g 795 9 puma INS 9 Puno gNS AP AP 7759 HDIH DSOC AP SSOCHAP y 28O Q 9 DSOT g 81786 9 81786 g 81745 8 81786 9 8 gOs AP 9 ans APp 8 9 8 9 9 IHDSOT AP 9 IHDSOT AP 9 IHDSOT AP g IHDSOT AP 9 dns ans amp ans 9 dns D IH DSOT A v IH DSOT A v IH DSOC A OY IH DSOT A 7 458058 f Wisi SDIHSOWV y WANS ANS AP Tans ans AP Wenssizas S 9 9 411581785 x 5 gt Zu L 9 OTSOW IH SOWV
4. __ 8 ans Qv IHDSOGA 5 9 ww oIlosOG 8 dns IN OO TOSOQ A a En s no mos p ING Gomo ortino nes z no 5145444 1080 9A NOISY3A SSE SC 559 v IAv139 a 9 NSAP ONON gv 9 2 81295 9 7 8129 _ gv Ws gt vi Ws y puno 8129 y Puno 8 Z as 7 Puno qns AP y puno griS AP i v BIzHS v sSlcasONOW _ __ 9 81295 8 81745 gv a 9 NSAP ONON a 9 S SAP _ a 9 S SAP ONOW a y NSAP ONON q y aNSAPONOW 9 WAS 5 WS 155 OTSOA OTOSTA OTSOA Qvjol2SOQ WIOTSSOCA OT OSOA n OTOA WIOTSSOCA Q OIOSOQA OT OSOA n 7 9715 81245 9715 8 qS 7 9715 81495 9715 81245 Eo 0 44 IF OF 8 mjn Nutr mics orm C4 en coa en oa 0 6 8 9 St r C 0 Z ae c 4 4 r4 4 T1 AG ME 95 ME 195 ME H us 195 AP TOE ME AC H OOZAAE SUL dE SE xs BERE NENN BEBE E OI AE O1X1 H
5. 109 APPENDIX 3 HOW DOES V DOSC BEHAVE WITH RESPECT TO WST CRITERIA 114 APPENDIX 4 HOW DOES THE DOSC WAVEGUIDE 15 APPENDIX 5 THE BORDER BETWEEN FRESNEL AND FRAUNHOFER REGIONS 116 APPENDIX 6 PATTERN CONTROL OF CONSTANT CURVATURE 118 APPENDIX 7 V DOSC RIGGING 120 L ACOUSTICS V DOSC Manual Version 3 2 10 01 6 119 LIST OF FIGURES Figure Wavefield interference for a conventional sound reinforcement system compared to a Sculptured V ae 10 Figure 2 Wavefront Sculpture Technology Criteria Illustrated Figure 3 Coplanar Symmely Ob VOS anne u 13 Figure da V DOSC System Block Dias an ae 17 Eigure 4b Example System Configuration aa iuo uu 18 Figure 5 V DOSC System Parts and Accessories 23 Figure 6 V DOSC Element Front and Rear Views 24 Figure DOSEBU MPER ni nase een ee ee ea 25 Figure 8 8218 Subwoofer Front and Rear Views
6. 59 Figure 23 Illustration of Flying Guidelines l u ua RSS ene E nennen 59 Figure 24 Illustration of Left Right Flying 61 Figure 25a Optimizing coverage and intelligibility 62 Figure 25b Optimizing Stereo IMAGING uu u itu tes uapa paqaq 62 Figure 26 Ihe SB2 18 as at eHe6t ansehen Rainer 64 Figure 27 The subwoofer array as an extension of the V DOSC system 65 Figure 28 Central location ground stacked subwoofer configuration 66 Figure 29 Subwoofer configuration with electronic arc processing 68 Figure 30 Terminology for the SUB ARC Sheet in ARRAY 68 Figure 31 Long Narrow Audience Format flat 70 Figure 32 Wide Audience Format Foxwoods Casino Installation 7 Figure 33 Stadium or Large Scale Outdoor Festival Format 72 Figure J 4 Arena een 73 Figure 35 System Behind the Stage
7. TW MOTOSOC AP WEIS 9 8 __ UIE g S AP HDIHDSOC AP_ AoTlosoc P veld 9 5 __ 0 HOIHOSOQAP W MOTOSSOCAP 0 sveldgDs AP WD Wweuansp puno 81085 MOTDSOC AP Wel ANS p puno BITES Wweuansp pun gs MOTISOMAP uveigansP WPUmDansAp AP AP AP AP Worssoar j Were QiHosOgw orosoc P j Were olosoc P 987458 volosoc P Were Worssoarr Wen __ 5 __ orosoc P Wen QW iHosoOdw Worssoar Wen oiosogc Wen IH 2SO 9 OTDSOT AP AP volosoc P Wan 9 012504 e IH DSOC AP 9 OTDSOT AP g 0125809 OY IH DSOC AP OTDSOT AP g O13800 IH DSOC AP 9 OTDSOT AP SH CIW DSOCA 9 O1DSOC A SD IHDSOQCA _ _ VIHKOSTA vabosodgc VOTTA NDIHOSOCA WOTDSOTA 9 81581745 DSOC A amp O12SOGA 81581785 AIN DSOTA amp O12SOGA V 91581785 QD CIW DS00 A 9 81581785 513534d 1080 NOISH3A VLX
8. D G LF RIHFRGH 15 wE D M SUB 14 D SUB 13 GND D K SB 12 D R 2 WAYFILLHF RIGHT RIGHT 11 ORANGE D P 2WAYFLLHF RIGHT RNIGHT 4 GND D N 2 WAYFILLHF RIGHT RNIGHT 10 BLUE D U 2 WAYFLLLF RIGHT RGHT 9 BROWN D T 2 WAYFILLLF RIGHT RGHT _ 8 GND D S 2 WAYFILLLF RIGHT RGHT DIC OUT XLR 1 rr OUT XLR 2 m LLL Tg OUT XLR 3 9 OUT XLR 4 I r O O O O O O O O 10 O O L ACOUSTICS V DOSC Manual Version 3 2 10 01 104 119 Table 156 MD24 W6 Socket Assignments W6 W6 CACOM CACOM PROCESSOR LOUDSPEAKE Socket COLOR CHANNEL PIN CHANNEL R CODE ARRAY 42 BLACK A C HE LEFTLEFT 41 RED A B HF LEFTLEFT 40 GND A A HE LEFTLEFT 39 BLACK A F MD LEFTLEFT 38 GREEN A E LEFTLEFT 37 GND A D M J LEFTLEFT 36 BLACK Aa J LIF X LEFTLEFT 35 YLLON A H LF LEFTLEFT 34 GND A G LF LEFTLEFT BLACK A M SUB LEFTLEFT LEFT LEFT N LEFT LEFT R 2 WAYFILLHF LEFT LEFT P 2WAYFLLHF LEFT LEFT N LEFT LEFT LEFT LEFT LEFT LEFT gt gt gt gt gt gt gt gt gt gt 2 sk G 2 2 2 2 2 2 2 2 2
9. G LEFT LEFT HF LEFT 2 2 6 HF 4 LEFT LEFT LEFT LEFT LEFT 18 GREEN B J LF LEFT 17 BROWN B H LF LEFT 1 GND B G LF LEFT 1 WHITE B M SUB LEFT 14 BLU B L SUB LEFT 13 GND B Kk SUB J LEFT 1 B R 2WAYFLLHF LEFT 11 BROWN B P 2WAYFLLHF LEFT 4 GND B N 2WAYFILLHE LEFT 10 BLU B U 2WAYFLLLF LET 9 YELLOW B T 2WAYFLLF LET GND B S LEFT NE XLR 1 ea XLR 2 B E 6 3 XLR 3 XLR 4 Bum sumar 3 1 0 8 7 5 3 1 0 2 eere L ACOUSTICS V DOSC Manual Version 3 2 10 01 105 119 7 7 APPROVED AMPLIFIER SPECIFICATIONS a L ACOUSTICS LA 48 The LA 48 is configured with the input sensitivity set for a constant gain of 32 dB For this setting the maximum power level is attained when the input is fed with a signal level of 2 30 Vrms which is equivalent to 7 2 dBV or 9 5 dBu At higher levels the limiters of the amplifiers begin to function and the clip LED indicators of the amplifiers light up For a more detailed description of the LA 48 please refer to the L ACOUSTICS LA 48 Users Manual A brief summary of important specifications follows INPUT SENSITIVITY 2 30 Vrms 9 5 dBu GAIN 32 dB gain specified setting for V DOSC I
10. d IH 2SOQ P 8 1 25 v v 125 q IH 2SOQ AP 8 O 9 SOGQ AP v IH v SOGQ AP q IH 8 OT 9SOG AP V IH DSOTAP v OT 9SOG AP q IH 8 O 9SOG AP v IH 2SOC AP v O OSOCAP q IH 2SOQ AP VOTDSOTAP v IH v O SOGQ AP q IH 8 O 9SOG AP IH DSOTAP v OT 9SOGQ AP d IH 2SOQ AP VOTDSOTAP v 125 q 8 O 9SOG AP V IH v O 9SOG AP q IH 8 O 9SOG AP V IH 2SOC AP v O 9SOG AP q IH SSOGQ AP 8 O OSOC AP v IH v O SOGQ AP AP AP AP AP A A ggowvunind VINATA lv SSOCA governi WII sodA 3509 IONAT 9 T PNA TA d IH 9 CIIM g g O1S2Wv Z IH DSOC A v DSOT A q q 91529 Z H DSOQA Vv DSOTA g IH SOMV q O1S2Wv Z IH DSOC A Vv DSOTA g 8 O1S2Wv Z IH DSOC A DSOTA A gHosoOG P gorosod lv GlWosoG gH2sOG P golosoa P WIHSSOQA GIN _ 9 WinssoaA V 5 25 9 OTOSOQ AP g ans _ Qv IHDSOGA WansscaA woIlosOQ g ans 9
11. Ar b c d Figure 24 Illustration of Left Right Flying Guidelines 60 119 10 01 L ACOUSTICS V DOSC Manual Version 3 2 b Tradeoffs Between Intelligibility and Stereo Imaging The left right configuration has the advantage of reproducing effects of spatialization and localization The area over which these effects is audible depends on the orientation of the left array with respect to the right array and is defined by the intersection of the isocontours for both arrays The more the arrays are rotated or panned onstage toed in the greater the area over which stereo imaging is experienced The less they are rotated onstage and the more they are aimed offstage the less stereo imaging is audible Typically for concert applications L R arrays are used at zero degrees or panned 2 5 degrees offstage Experience has shown that this provides the best tradeoff between stereo imaging evenness of horizontal coverage and reduction of the potential for build up of upper mid bass energy in the centre There are also tradeoffs with respect to intelligibility when aiming arrays Psychoacoustically improved intelligibility is obtained when the isocontours of both arrays do not overlap excessively Provided that audience coverage is correct intelligibility is optimal when only one array radiates on a given audience area If two arrays are to cover a common area intelligibility losses result when the distance separat
12. 9 O 1 OSO CHAP v Oll DSOTA HOT DSOT A 7 AMS BIZAS AP HOSTA g H 9 21 SO CHAP v H DSOO CHA v Cl OT DOTA 7 81798 X AP FOSCOKCEA di H 8 21 SO CHAP W IH DSC CHA v OIW DSOTA HOT DOTA 7 AMS BIZAS OTX E BEE AA m v TI v H OSOCA v OT DOTA z ung 81788 E H 8 ans 11719 v IH 2SOCA vi Cl HOT DOTA 7 ANS 817 98 OTMFISCHTA 8 ans 11719 v H DSC CHA vi Cl OT DOTA 7 ANS 817 98 IH X ISOTA 8 ans 11719 v Cl OISSOQCA 7 AMS 12 95 Ol ISOTA munas 9 ING 100 somos p 100 unos ING anos g ING ounces p JWYN 135394 5145444 1080 9A NOISUSA 9CCdCl V LX XTA DP226 Presets Table 9 41 119 10 01 L ACOUSTICS V DOSC Manual Version 3 2 1 11 CO24 CONTROL OUTPUT PANEL L ACOUSTICS 24 CONTROL OUTPUT LEFT LEFT RIGHT RIGHT 1666 1666 Figure 12 V DOSC CO24 Control Output Panel Digital signal processor outputs are assigned to MULTI return lines via the CONTROL OUTPUT panel Internally digital processor XLR outputs are patched to the 24x female XLR patch bay on the internal side of the CONTROL OUTPUT panel All MULTI lines are paralleled with the Left Left Left Right and Right Right CA COM connectors These individual CA COM
13. Note the site angle for element 1 is essentially equal to the BUMPER site angle since the first element is attached to the BUMPER with minimum separation within physical tolerance limits using the BUMP ANGLE strap When the system is pointing down negative site angle for 1 the top element will tend to close against the bumper normally this is indicated by a negative 2 Angle Stress value in MECHANICAL DATA cells When pointing upwards there will be a small gap between the first element and the BUMPER and therefore a difference between site angle and the BUMPER site angle Therefore you should always attach a laser and or remote digital inclinometer to the top of element 1 not the BUMPER itself in order to accurately measure the true focus of the top element Also tabulated are continuous A weighted SPL estimates throughout the vertical coverage pattern of the array on an element by element basis These dBA estimates are derived using a Fresnel type calculation see Appendix 2 using a 2 kHz reference frequency for a 4 dBu nominal input signal level 17 dB of headroom remains Since the dBA calculation considers discrete V DOSC elements not sections of the continuous radiating line source array the resolution of this calculation is not L ACOUSTICS V DOSC Manual Version 3 2 10 01 51 119 sufficient for the user to design for constant dBA throughout the audience area Users are advised to refer to the visual spacing between element f
14. L ACOUSTICS V DOSC Manual Version 3 2 10 01 62 119 subwoofers are operated with the same polarity this is why the sub polarity is inverted for output 5 355 or output 6 226 366 of the X preset Under these conditions time alignment is a compromise that requires a choice as to which locations and which frequencies can support the energy losses There are three ways to minimize these problems Use the X preset input B output 6 which reverses the polarity for the sub channel then optimize time alignment between low and sub channels Separate the input signals for the array and subwoofers i e run the subwoofers off a separate drive signal using an aux send on the console Physically separate the array and subwoofers by a couple of meters then optimize the time alignment Adda center horizontal line array to replace or augment the split L R subwoofer arrays Good results can be achieved using these recommendations provided that the low pass filter for the subwoofer channel does not exceed 80 Hz Note for BSS 355 and 366 the standard X preset can be used with aux drive for subs select Source B for output however since subs are operated from 27 200 Hz effective 120 Hz lowpass filter with additional channel eq there may be subjectively too much bass information compared with sub information coming from the ground stacks for the closest audience members With aux sub drive the standard X preset has the advantage o
15. The following explanation provides a more intuitive description of WST criteria along the lines of the NYC Convention preprint with the intention of describing where the ideas for the research that finally led to WST came from Returning to the interference problem introduced in Appendix the time frequency relationship can be expressed in a different way i e in the distance wavelength domain Since c f i e wavelength speed of sound divided by the frequency and c t i e path length difference speed of sound times the arrival time difference pressure cancellations occur when the path length difference between two wavefronts arriving at an observation point M is 2n 1 A 2 where n is an integer We can therefore conclude that discrete sound sources produce a totally incoherent wavefront due to comb filtering effects as soon as the path length difference between the sources to a given point M is greater than A 2 half a wavelength Let s consider a line array of discrete sound sources providing almost equal pressure levels at M We want to find the conditions for constructive coupling of the sound sources for a given frequency f c gt Assume that the time of the first arrival at M of this multiple source wavefront is t d c where it is seen in Figure 46 that the first arrival is due to source i physically the closest source to M di A 2 Figure 46 Destructive interferen
16. WOSSIIOYd TSIO 1 1 asnoH Y 3991 eee ee eee ee eee eee eee eee ee 22 255225222222 eee eee eee eee ee 22222252222 0000000009900 3 MAX D TES NY on v E D Figure 4a V DOSC System Block Diagram 1104 18 2 JONVY TINA NI 8 16 NI LHOR NI 1431 TWIN Ya QA div J ANN ANN ANIT 17 119 10 01 L ACOUSTICS V DOSC Manual Version 3 2 ER m ee ua ie a EM M aal k um b ee a dp m er Olle elle eee N ke e k i EE m m EET a Im iF a 99 o ue DIE mE Im cans 8 1 sod EH Me X Cn x Ag Wl Mile AP DESDE HAP SLAP TATUS Jr EX c Y xa hant aly owe EC NUI A Au f x Kalte
17. H 28OC AP OT DSOTAR 7 OSAP VE Hmmm u IH Hic OSC A H 2252 OW SOA H IH SOc A u GO OSC 7A IH OSC A FON SOC u IH u GO OSC 7A WF H OSA FON u IH SOc A u GO SO CA IH OSA FON SOC A vJ CY OSA FEN H OT ISOTA J o mmm MA OTXME ISOTA e lo OSOA DT OTME ISOTA rm vo q dris SHY T YS M A d dris u dris IH sv x H sv Nd H OSC AP vU SOA viU SOA viU OSC CAP NH OSA H OSA IH OSA OMNIA FON SOc A s OW SOC A vU OSA OT OSA viU OSA FE 3 XO HV OSOKFA APTOSCORTEA E E 8 ans v IH DEOT AP y v IH SO CTA v Ola DEOTA OOO A AP HISWA pi di IH 82 9 v IH DSC v Cl HOT DOTA 7 AMS BIZAS AAF SOR DSOH FA di IH 82 9 v IH 2SOCA vi Cl 2SOQCA OT DOTA 7 81798 AF SOHVAT A gq IH SO 9 O v Cl HOT DOTA 7 ANS 81798 61 X SOHV C OSCOC A di IH SoH di 82v v IH 2SOCA vi Cl DSOTA OT DOTA 7 ANS 817 98 8l OTX SOHV OSOCEA BR T H di H 28OCAP dicr1280QrAP v IH DSC vi Cl SCO CHA OT DOTA 7 ANS B 12 95 21 AAF AP HOSTA di H
18. H OBAAE AG iH2sOQ P 3DOTSSOQ P g NSAP olssog P ISAP Werne 108ME AG gt 5 WorssocaA anscap_ 9019502 qap amp DIHISOGAP__ oilcsod IHOSOTAP eolosod JW ASAP AE AG AP g IH 55 d 1 5 8 9 IH 50 v O1 D500 AP 4 it q IH 2SOQ P d O1250 Q7 AP 8 5 9 IH2SOQ 9 O12SOQ AP 4 97 gt AE AC IH 280Q P Gorsog 1 olcodg o1ssocgve x Oct we C iHosOg C orlssog 1 amp Qolcsod w Ott we 01 O IHOSOC Ap C orlssod 1 WorzsocA 90125 OF C IH OSOC AP G OTOSOQ AP QD IH OSO AP 901 QD IHOSOQLAP 5 01 5 z 0 A AP 8 IH2SOQ g oissoga W HssogA gt ols sogc Werde WanssogA oissoga WiHssogA gt 01250 Were 01 WorssoaA W HssogA gt 01250 g IH OSO TA D CIIH OSO A d OT OSOA OD IHOSOQ A 0 49 A A A mtr 8 3DN 31114 8 ISNA 9 5 x SOTA MOTISOTA 9 9158 1295 A A A
19. L ACOUSTICS V DOSC Manual Version 3 2 10 01 72 119 e Invisible Configuration System Located Behind the Stage Originally designed with Alain Courieux for opera performances 1 Video Screen WW E W dr 2 Figure 35 System Behind the Stage L ACOUSTICS V DOSC Manual Version 3 2 10 01 73 119 4 INSTALLATION PROCEDURES In the following sections detailed installation procedures for stacking and flying V DOSC are presented Please follow these procedures carefully and at all times remain safety conscious 4 1 STACKED SYSTEM a Stacking and Connecting For stability reasons the maximum number of V DOSC elements that can be stacked is 6 In this case each screwjack presents a load of 350 kg The strength of the supporting floor should be carefully examined to determine if such a load can be supported sheets of plywood or steel plates can be placed under individual screwjack feet in order to help distribute the load Generally two people can comfortably build a 4 high stack for 5 or 6 high a forklift is useful Once the floor location for the stacked array has been determined the BUMPER is placed in the desired location oriented upside down so that the two rotating legs on the BUMPER are free to swing upwards Lower the height adjustment blocks on all four screwjacks to the minimum position Mount the screwjacks on all four corners of the BUMPER by sliding the screwja
20. LET 9 B5 2 B T 2WAYFLIF LET 8 GND B5 1 B S 2WAYFLLLF LEFT OUT 1 rem OUT 2 OUT 3 OUT 4 L ACOUSTICS V DOSC Manual Version 3 2 10 01 102 119 Table 14b CO24 W6 Socket Assignments REMOTE F 4pin XLR 2 ORANGE REMOTE F 4pin XLR 3 YELLOW REMOTE F 4pin XLR IN HA GND W6 W6 XLR XLR CACOM CACOM PROCESSOR LOUDSPEAKER CODE 41 C4 2 C B H RECHT 37 C8 1 C D MD RECHT GND 31 RD C6 3 C R 2WAYILH RIGHT 30 BLUE C6 2 C P 2WAYFLHF RECHT 25 GREEN D4 3 D C HF RIGHTRIHT 24 WHITE D4 2 D B HE 23 p 1 D A HE 21 GREEN D3 3 D MD RIHTRIGHT 20 yellow Do 2 D E MD RIGHTRIHT 19 D3 1 D D MD GREEN D2 3 D J LF RIGHTRIGHT 17 ORANGE 02 2 D H LF 16 GND p 4 D G LE 15 WHTE pt 3 D M SUB 14 uow m 2 D L SUB RIGHTRIHT 13 Di 1 D K SUB RIGHFRIGHT 12 WHITE D6 3 D R 2WAYFLLHF RIGHT RIGHT ORANGE D6 2 D P J 2WAYFLLHF RIGHT RIGHT 4 1 D N 2WAYFLLHF RIGHT RIGHT 10 BLUE D 3 D U Z2WAYFLLLE RIGHT R
21. Part Codes BUMP24 251 BUMP25 BUMP26 BUMP27 11 SPACER Used with ANGLE STRAPS to provide the desired spacing between V DOSC elements when stacked or flown Part Codes SPAC25 1 3 SPAC25 2 SPAC26 3 SPAC27 4 SPAC28 5 5 for use with corresponding BUMPxx 12 MULTI MC2875 28 pair multiconductor return snake 00 m 325 ft length fitted with 84 pin MASS connectors at each end used for connecting CONTROL OUTPUT panel typically located at FOH to MULTI DISTRO panel for subsequent distribution of drive signal to the amplifier racks L ACOUSTICS V DOSC Manual Version 3 2 10 01 19 119 13 AMP LINK DOM2 6 pair multiconductor cable 2 m 6 5 ft length with 2x female 19 pin bayonet CA COM connectors for distributing signal from MULTI DISTRO panel to amplifier racks and for jumping between AMP RACKS 14 CROSS LINK DOM30 6 pair multiconductor cable 30 m 100 ft length with 2x female 19 pin bayonet CA COM connectors for cross stage connection from MULTI DISTRO panel to amplifier racks 15 LINK EXTEND DOMP 9 male male CA COM adapter for connecting two AMP LINK or CROSS LINK cables when longer lengths are required 16 LINK BREAKOUT DOMM Multipair cable adaptor consisting of Ix female 19 pin CA COM connector at one end 6x male XLR connectors at the other used as a LINK cable breakout for patching and testing purposes 17 LINK BREAKOUT DOMF Multipair cable adaptor consisting of
22. grass in open air situations the measured response may display a high frequency loss this does not correspond to reality In this case a sheet of plywood can be useful for reducing the effect of this on your measurements For the same reason as for floor reflections the measurement microphone should not be placed close to any reflecting surface a road case with the lid open and an absorbing blanket placed just below the microphone can help absorb the first reflection Equalizing a subwoofer system is the most tricky part of the tuning procedure since measurements taken at a single location can be misleading Indoors there are room modes to consider and you may be located in a pressure null or maximum depending on the location and the frequency Always be sure to verify the effect of your adjustments throughout the audience b Step By Step Tuning Procedure In general terms the installation and tuning procedure should go as follows Room Dimensions ARRAY 2000 System Install System Focus Preset Selection FOH Drive Rack CO24 Channel Assignment System Check Coverage Check gt Time Align gt Balance gt Tune Confirm the installation by following the trim and angle adjustments outlined in Section 4 2 d 2 Send pink noise to each array one array at a time band by band and have an assistant spin up each amplifier channel one at a time For all bands turn up amp channel then amp channel 2 to confirm that
23. right depending on physical constraints regarding snake runs alternatively this panel can be mounted in the AMP RACK that is first in line for patching purposes An AMP LINK cable is run from the MULTI DISTRO panel to the appropriate CA COM connector of the first AMP RACK e g B lines for house left if the AMP RACK is located stage right AMP LINK cables are then used to connect all subsequent stage right amplifiers so that all receive B lines including subwoofer amp racks which are configured using the COMB connector as described in Section 6 A CROSS LINK cable is then used to distribute C lines for house right from the MULTI DISTRO panel cross stage to the stage left amplifiers These racks are connected in the same way using AMP LINK cables Separating left and right signal distribution lines is an effective way to avoid potential ground loop problems Similar connections are performed for the A and D lines to accommodate Left Left and Right Right arrays as necessary L ACOUSTICS V DOSC Manual Version 3 2 10 01 43 119 2 V DOSC ARRAY SPECIFICATIONS 2 1 ISOCONTOUR IN THE HORIZONTAL PLANE a Horizontal Coverage Angle of a V DOSC Array According to AES recommendations horizontal coverage angles are specified over an angular window with no more than 6 dB deviation For the case of V DOSC the 6 dB points are at 45 off axis and the horizontal coverage pattern is strictly symmetrical with respect to the 0 axis a direct conse
24. uns 8488 0 5 uns 084848 ABM uns 8488 at Tod 97 11719 Hd IH GSO CAP d Cy OSC AP IHOSOQAP at Tl at Tod at NO OSOCQ AP NO DSC CAP FA FIO DSC CHAP H Si MEISOCTAP OT SI IH 001 MEISOCTAP 1001 AE UOSOCrAP 97 11719 97 11719 97 11719 d IH SSO CAP dH H GSO CAP dH IH SSO CAP d OSC AP d OSC AP d OSC AP IHOSOQAP IH SoC AP H OSC AP 8 IH Soe d 28 8 ans 9 5 IH v O1 SOM ans qA sp IH ME SOUY di IH 82 di O 1 8 ans gngAP H SONY SOM dns gng AP Be 00 OTUDSAP ME SH di IH SOx 9 82v 9 ans B 179 H SOM WO Sou 7 ANS 817 98 00 81705 AAE SOHV di IH 82 di 82v 9 ans 81798 H SONY WO SOU 7 ANS 81798 9p 0000 81255 ME S XH II9I I I I2 KYW P VP V YPWXI IBY lt II II II II6I C K I C CCG C II O IIZ lt I I III I I I IICI IIIIISIKYS V SSSSESSEAUI V B I I I I I I I Y II II II II IIZ I I IXI9 IWI W IzZ IIII I II I ZINWO ZKIWI I IK KW I I a ae WESES I WY I O II RW I WG II I I I I IW I II III
25. 1 CH B 3 CHB 1 z LA 4B 21 1 YELLOW G LOW SUB LF FILL amp CHB 1 2 D a a LINE IN A B c D F G J K RK12 2 Amplifier Rack Wiring Diagram for PADO2 OO CO CHANNEL CHANNEL A WHITE XLR Input BROWN XLR Input RED Speakon Output db Hd p BLUE Speakon Output 22 UU UU C LEO Toros Be d UUUWUUUUUUU BF E lan Tin gc P ORANGE XLR Input VIOLET XLR Input D u E Ti 28 2 IS YELLOW Speakon UIP Ut m gt EE amp p GREEN Speakon Output m Ee Set ws en Ze lt pr m an en m ab mam i I 1 j EC gt i ig rg l C J h Ni eff 2705 34 Pj 2 E L ACOUSTICS V DOSC Manual Version 3 2 10 01 32 119 1 8 POWERING V DOSC Amplifiers approved for use with V DOSC include L ACOUSTICS LA 48 Lab Gruppen 4000 QSC PowerLight 6 0 and CROWN MA 5000VZ L ACOUSTICS specifies amplif
26. 22 9 inches Clearance from the front rack rail to the front of the rack is 9 5 cm 3 7 in Clearance from the rear rack rail to the rear of the rack is 6 cm 2 4 in The depth from front to rear rack rails is 42 5 cm 16 7 in and the depth from front rack rail to the rear support points for the LA 48 amplifier is 39 cm 15 35 in Due to the switched mode power supply technology employed in the L ACOUSTICS LA 48 the rack weighs only 98 kg 216 lbs Using the COMB connectors located on the Amp Panel PADO4 the rack can be configured so that A and B channels are independent Depending on how the rack is to be configured 2 WAY 3 WAY or SUB COMB connectors are selected Essentially the COMB connectors route the desired input lines from the 19 pin CA COM connector to the appropriate amplifier inputs for A and B channels respectively Using separate COMB connectors for both channels it is possible to assign the A channels and the B channels independently Therefore half an amplifier rack can power up to 3 V DOSC 6 total 4 SB218 subwoofers 8 total or 6 dV DOSC 12 total In terms of construction the amplifier rack is made of a lightweight aluminum space frame with heavy duty bracing internal shock mounting standard rack rails and provision for rear support of amplifiers Clear unbreakable polycarbonate lexan front and rear doors allow the user to quickly see how the racks are configured and can be conveniently stored inside the rack dur
27. 4 amplifiers rack Figure 11 V DOSC AMP Panels The V DOSC PADO4 amp panel allows for connection of loudspeakers input signal and output signal loop through The panel has dual 8 pin female CA COM connectors for loudspeaker connection and two male 19 pin CA COM connectors for input signal connection using either AMP LINK or CROSS LINK cables and for jumping to subsequent amp racks using AMP LINK cables As mentioned above the COMB connector allows the user to reconfigure the AMP RACK for either 2 way 3 way or SUB operating modes Internally two sets of 4X male XLR fanouts connect the input signal from the COMB connector on PAD04 to the amplifier inputs For the CA COM connector lines 5 and 6 are always assigned to 2 way fill high and low respectively Line 4 is reserved for subwoofer drive while lines 2 and 3 are for V DOSC high mid and low respectively In 3 way mode 8 pin loudspeaker CA COM pinouts for channels A and B are as follows A B V DOSC LOW AMP 3 C D V DOSC LOW AMP 4 E F V DOSC MID AMP 2 G H V DOSC HIGH AMP In 2 way mode 8 pin loudspeaker CA COM pinouts for channels A and B are as follows A B HF AMP 3 LF AMP 4 G H HF AMP I E F LF AMP 2 Either DOFILL or DO2W adapters are used to convert from 8 pin CA COM to dual Speakon connectors Individual Speakon pinouts I I dV DOSC LF 2 2 dV DOSC HF For complete details rega
28. 5 0 5 0 75 0 75 will be obtained for elements l 8 This provides better spacing of element impact zones over the audience in flat open air situations When the array is pointing upwards the centre of gravity shifts forwards and V DOSC elements tend to open naturally providing the nominal ANGLE values 0 75 1 3 2 0 3 0 4 0 and 5 5 Therefore for V DOSC array with upwards tilt very little ratchet strap tension is required Typically the bottom 2 3 elements will need to open up slightly and SPACER blocks should be used for this purpose or moderate ratcheting The most precise way to work with the ratchet strap is to have a remote inclinometer on top of the array to measure Site Angle and a handheld digital inclinometer to measure the bottom element site angle Fly the array using the ANGLE strap values calculated in ARRAY 2000 and float the array above ground level at a height where the ratchet strap handle is accessible While referring to the remote inclinometer adjust the front rear motors to give the correct Site angle that was calculated in ARRAY 2000 Allow the array to settle then measure the site angle of the bottom element Adjust the tension of the ratchet strap until the site angle of the bottom element agrees with the value determined in ARRAY 2000 At this point the vertical coverage of the array is correct and agrees with the VERTICAL COVERAGE parameter that was simulated in ARRAY 2000 Next take the array to the
29. 8 013800 WIHSSOTA ir oF Sy 144 EF 04 DANS Cy CDAEN T 6 N ans q 9715 G DANS 5 8 905 2 EMT de DAE E 9 9715 G e g ANS c 9 9 15 e ii ii Cd Cd Eos t 8 9015 9 48 g 915 4 g gnis 9 4 8 grs 48 DANS 9 A DANS 9 Ar DANS 9 DANS Oy DINS 9 g 9715 Oy 48 B 85 zz dE 515 iev y ievr y Ae NS OEE 9 918 9 48 ans 9 mi lt lt BIZUS ME WJS1I I n 8124 A F AP IH UNS AP AAP GNIS AP AAP AP IH 81295 O1 81 GUS XAE IH 81295 ME O1 24 ME OLI AE IH SAP 007 ME 004 S AACOSOC AP O1S MULOSOCAP X W IH SOTA X W SOTA H X SOTA X W SOTA Ab SOTA JWWN 135394 DP224 Presets Table 8 40 119 10 01 L ACOUSTICS V DOSC Manual Version 3 2 XTA DP226 VERSION 6 0801 PRESETS FOR V DOSC d H Hcr oso 9 uris v J H OSC AP vU oso v diis NENNEN 041 ME pi 43 DE uns 8488 ABM
30. ARCS and dV DOSC with a full grasp of the operating theories and principles behind the system The CVE is capable of recommending and endorsing QVTs along with supervising the QVTs during their apprenticeship period towards becoming a full CVE In some cases CVEs may also conduct V DOSC training sessions To be included in the official CVE list that is distributed to members of the V DOSC Network the operator has to meet the following criteria Must be recommended by a recognized CVE or official representative of the V DOSC Network Must have participated in V DOSC training sessions on theory and rigging Must be known and certified by an official representative of L ACOUSTICS The Qualified V DOSC Technician and Certified V DOSC Engineer are important representatives of the V DOSC Network While the V DOSC Network provides the V DOSC system on a rental basis it is the QVT and or CVE who accompanies the system at each installation to ensure that system performance is optimal We hope that you carefully follow the guidelines presented in this manual it is in everyone s best interest that V DOSC is deployed correctly and optimally in the field NOTE L ACOUSTICS provides QVT training seminars in North America Europe and at the factory in France please contact L ACOUSTICS for the latest training schedule In some cases training can be provided on site L ACOUSTICS V DOSC Manual Version 3 2 10 01 15 119 I V DOSC THE UNIVERSAL STANDAR
31. Ix female 19 pin CA COM connector at one end 6X female XLR connectors at the other 18 V CABLE DO7 DO25 Main V DOSC loudspeaker cable 8 conductor 7 m 20 ft or 25 m 80 ft length equipped with male female CA COM type connectors for connecting V DOSC elements to the amplifier rack 19 V LINK CABLE DO 7 V DOSC loudspeaker link cable 8 conductor 0 7 m 2 ft length equipped with male female CA COM type connectors for parallel connection of V DOSC elements 20 F CABLE SP7 SP25 Fill loudspeaker cable 4 conductor 7 m 20 ft or 25 m 80 ft length equipped with CA COM to 2x Speakon connectors for connecting 2 way fill enclosures to the amplifier rack 21 F LINK CABLE SP 7 Fill loudspeaker link cable 4 conductor 0 7 m 2 ft length equipped with Speakon connectors for paralleling 2 way fill enclosures 22 SUB CABLE DOSUB Subwoofer loudspeaker cable 5 m 16 ft length with male 8 pin CA COM connector and four Speakon connectors for connecting 4x SB218 subwoofers to the amplifier rack 23 SUB EXTENSION CABLE Subwoofer extension cable 10 m length for use with DOSUB 24 DELTA PLATE BUMPDELTA Used to attach two motors to the rear fly point of the BUMPER allows for pan adjustment of a flown V DOSC array 25 SB218 FLYING BAR Flying bar for rigging up to eight SB218 enclosures deep in a vertical line array 26 DO2W DOFILL Adaptor cables for use with PADO2 or PADO4 2 way C
32. U pins see Fig 36 f g Connect the top element to the BUMPER using two BUMP ANGLE straps This locks the top element to the BUMPER NOTE the angle for the top element is set by angling the BUMPER during the final step of array angle adjustment this is the site angle of Element as specified in ARRAY 2000 not the autofocus adjust angle see Fig 36 h Referring to the ANGLE strap values that have been predetermined using ARRAY 2000 proceed to connect one end of all ANGLE straps to the flytrack sections on both sides of all elements of the array except for the bottom element Available ANGLE straps are 0 75 1 3 2 3 and 4 degrees by moving a 0 degree ANGLE strap one hole location closer 5 5 degrees is obtained Although exact flytrack hole location is irrelevant since the length of the ANGLE strap bar actually controls the angle between enclosures as a convenient reference you can place ANGLE strap fittings so that the shackle is located in flytrack location 3 Orient the ANGLE straps so that the ring end of the fitting is facing to the left down once cabinets are flown and the fitting is located at the left side of the flytrack bottom of the flytrack section once flown in flytrack hole position 3 from the end L ACOUSTICS V DOSC Manual Version 3 2 10 01 76 119 If ANGLE straps are connected with the text out it is convenient to perform a last minute check to confirm that all values are correct In addition when the array is f
33. a flat isophasic constant phase wavefront allowing the overall assembly of multiple elements to produce a single extended sound source Since the angle of separation between adjacent elements is adjustable the wavefront can be focussed by physically shaping the array Through successful coupling over the entire audio frequency range V DOSC produces a consistent wavefront over a large area with very little fluctuation in frequency response and sound pressure level L ACOUSTICS V DOSC Manual Version 3 2 10 01 11 119 The heart of the V DOSC system is the internationally patented DOSC waveguide Essentially the DOSC waveguide permits fulfillment of the first condition of WST for frequencies higher than 1 3 kHz i e the wavefronts generated by individual DOSC waveguides are planar and their combined surface area accounts for at least 80 of the target surface area provided that the relative angle between adjacent enclosures remains less than 5 degrees For traditional horn loaded systems coherent summation is simply not possible at higher frequencies since the wavelength becomes progressively smaller than the physical separation between horn and driver assemblies and neither of the two WST criteria can be satisfied As a result interference occurs throughout most of the assigned high frequency range see Appendix By comparison a V DOSC array is a full spectrum coherent speaker system even for the highest frequencies As with any speaker syst
34. also to our assessment on execution documents attached b Factory visit on 22 12 95 We had a visual check of the hanging system then we saw the hoist intervention of the whole set we have no remark to make We issuc a FAVOURABLE ASSESSMENT on the V DOSC hanging system This ASSESSMENT is valid during 3 years i e limit date june 21 2002 Issued in Noisiel on October 10 1996 Translated in Paris on November 27 1998 Modified on june 21 1999 HEAD OF THE SPECTALISED FRAMEWORK EXPERT TECHNICAL DEPARTMENT auci D VIBURNI 47 GEORGES MARCHAND DANIEL BERGER amp 0 55566064 L ACOUSTICS V DOSC Manual Version 3 2 10 01 119 119
35. be less than 4 4 at the highest operating frequency this corresponds to less than 5 mm curvature at 16 L ACOUSTICS V DOSC Manual Version 3 2 10 01 10 119 4 For curved arrays enclosure tilt angles should vary in inverse proportion to the listener distance geometrically this is equivalent to shaping variable curvature arrays to provide equal spacing of individual element impact zones 5 Limits exist given the vertical size of each enclosure and the relative tilt angles that are allowed between enclosures STEP EQUIVALENT STEP e 5 5 PROVIDED THAT CRITERIA CRITERIA N 2 Combined area STEP lt A 2 of discrete sources over the bandwidth HI W H2 W of operation 2 B096 of target area H W Figure 2 Wavefront Sculpture Technology Criteria Illustrated c V DOSC The Solution V DOSC is the first exact embodiment of the principles of Wavefront Sculpture Technology V DOSC stands for Diffuseur d Onde Sonore Cylindrique in English this means Cylindrical Sound Wave Generator The V in V DOSC refers to the V shaped acoustic lens configuration employed for the mid and high frequency sections V DOSC was designed as a system consisting of identical vertically arrayable elements Individual transducers are physically arranged within each enclosure so as to meet WST criteria frequency band by frequency band when the enclosures are arrayed together Each element radiates
36. calculated trim height or bottom element elevation that was determined in ARRAY 2000 Since front and rear chain motors can run at different speeds once you are at trim you must reset the focus angle of the array using either the remote inclinometer or by referring to the laser Repeat this process to ensure that the vertical coverage and focus of Left and Right arrays are exactly matched L ACOUSTICS V DOSC Manual Version 3 2 10 01 80 119 8 h L ACOUSTICS V DOSC Manual Version 3 2 10 01 81 119 k I 0 P L ACOUSTICS V DOSC Manual Version 3 2 10 01 82 119 q L ACOUSTICS V DOSC Manual Version 3 2 10 01 83 119 ii iii Figure 36 Photo sequence showing the steps involved in flying V DOSC L ACOUSTICS V DOSC Manual Version 3 2 10 01 84 119 Flying Amplifier Racks In some situations it is desirable to fly amplifier racks behind the V DOSC array Shorter speaker cable runs have the advantage of lower cable resistance resulting in more effective signal transfer since there is less energy dissipated as heat in the cable Reduced cable runs can also improve damping factor and potential frequency dependent losses due to the skin effect in extreme situations Remote control and monitoring of amplifiers is highly recommended for flown amplifier rack installation for obvious reasons Currently there are no provisions for flying amplifier racks off the V DOSC BUMPER
37. connectors can be used in situations where CONTROL RACKS are located onstage eliminating the need for a MULTI DISTRO panel or when it is desirable to run separate drive snakes to remotely located AMP RACKS For example in some cases amplifier racks may be located at delay towers behind the FOH location and separate snake runs required or for smaller club theatre shows two Cross Link DOM30 cables can be run for Left and Right instead of the MULTI In addition the availability of individual CA COM connectors allows a LINK BREAKOUT cable to be connected to these outputs for testing purposes For amplifier remote control monitoring 4 pin XLR inputs and outputs are assigned directly to the appropriate MULTI lines This control panel configuration allows maximum flexibility while providing a scaleable architecture that can be used for small medium and large systems We will discuss the largest system application in detail since small and medium systems will adhere to the same MULTI line assignment standards and are considered as subsets of the large scale setup A large scale V DOSC system typically consists of Left Left L L Left L Right R and Right Right V DOSC arrays Each of the four arrays can have associated 2 way dV DOSC downfill enclosures and SB218 subwoofers Therefore each L L L R and R R array requires 6 drive channels 3 for V DOSC 2 for dV DOSC and for subs Since there are 4 arrays this requires 24 drive channe
38. crossover presets for the following reason Without proper instrumentation and spatial averaging adjustments made at one location e g the mix position are not optimum at all other locations within the defined coverage region of the system When made by ear such adjustments are often misguided the user may be in a local room mode low frequency pressure maximum or minimum and or may be hearing a cancellation or addition due to crossover misalignment that sounds good at that specific location but what about all others Meanwhile the same result could have been achieved while preserving the power response of the system and satisfaction of WST criteria by using the correct crossover preset and a simple equalization cut or correct time alignment of subwoofers The bottom line is that making sure that V DOSC is used properly is in everyone s best interest and it is up to the Qualified V DOSC Technician and Certified V DOSC Engineer to maintain quality control standards Quality control starts with good sound design proper array design accurate installation correct preset selection and a solid methodology for system tuning Restricting access to presets is in no way meant to restrict the creative process on the contrary the overall systems approach is intended to enhance it by ensuring quality control and repeatability In practice all presets are distributed to end users via PCMCIA Card so that the presets remain software protected
39. degree for ANGLE straps when cabinets are stacked versus flown i e 5 L ACOUSTICS V DOSC Manual Version 3 2 10 01 74 119 mm degree The relationship between ANGLE strap value and stacked angle is tabulated below Table 11 Angle Strap Values ANGLE NOMINAL NOMINAL COLOUR FLOWN STACKED BUMP 16 NA Yellow 075 55 0 75 5 5 1 75 do not use Rd 2 This means that ANGLE strap values should be selected by taking into account the additional degree difference for stacked versus flown For example if ARRAY 2000 simulations indicate that a 4 degree angle is required between elements and 2 select a 3 degree angle strap for actual installation Angle tolerances can also arise due to small variations in enclosure construction and SPACER block placement Use your measurement tools digital protractor or angle inclinometer to determine the effect of these tolerance variations and to minimize their impact The same procedures are followed for all other elements of the array until stacking is completed NOTE it is easier to place SPACER blocks between elements as the array is built instead of inserting them afterwards The correct angle for the entire array is obtained by fine adjustment of the BUMPER screwjacks Focus can be checked easily by sight looking from the rear of the array through the small space between the top element and the second one the lower wall of the top element should be aligned so as to aim towa
40. front fill 14 Stereo 4 way plus stereo 2 way fill stereo down or front fill 15 Stereo 4 way plus separate sub drive plus single or dual mono 2 way fill 16 Stereo 4 way plus separate sub drive plus stereo 2 way fill 17 Stereo 4 way plus 2 way Left Left and Right Right offstage fill 18 Stereo 4 way plus 2 way Left Left and Right Right offstage fill plus dual mono 2 way fill 19 Stereo 4 way plus 2 way Left Left and Right Right offstage fill plus stereo 2 way fill 20 Stereo 4 way plus 3 way Left Left and Right Right offstage fill 21 Stereo 4 way plus 3 way Left Left and Right Right offstage fill plus dual mono 2 way fill 22 Stereo 4 way plus 3 way Left Left and Right Right offstage fill plus stereo 2 way fill 23 Quad 4 way with quad 2 way down fill 24 Quad 4 way with quad 2 way down fill plus separate sub drive with electronic arc capability 25 Quad 4 way with quad 2 way down fill plus separate sub drive with electronic arc capability plus mono 2 way front fill and or2 way center fill As you can see the V DOSC system provides a very flexible scaleable approach to sound design For a general overview of these operating modes please refer to Figures 37 and 38 For details regarding specific array configurations and their suitability for given applications please refer to Chapter 3 Elements of Sound Design Specific details regarding MULTI line assignments for these operating modes are discussed in Sections 5 5 N
41. gains for a 1 5 1 V DOSC SB218 cabinet ratio are sub 4 low 0 mid 5 high 5 Version 5 preset names and descriptions for BSS 355 366 and XTA 224 226 processors are given in Tables 6 7 8 and 9 respectively Full details of channel assignments and user adjustable parameters are provided in the Preset Description sheets that are distributed with the processor PCMCIA cards L ACOUSTICS V DOSC Manual Version 3 2 10 01 37 119 Q V gt LL 2 LLI 9 LLI co e O 2 9 gt LA LA 2 LL 9 9 O w S A v v C Av g IH Suv 8 IH Suv 8 IH Suv g IH Suv H SOM 7 8 O SDT v H SOWv vIOTSDUY 8 IH Sou 8 O Sou v H S2Wv 9 SDM a punoBaizas v iHosoGQ P v uvouans P gizas tvjorosod e visveusns P 2 ansAP_ Qv orosod e wiusveusns P g punog WW IH 9 OTOSOQ AD ansAp a go1lssog P tv inosoGg P 1v OTl2SOQ P SSO Ap go1ssog iv iincsog a go1lssog P IH OSO v OTl2SOQ P 8 IH 2SOQ AP 8 01 lt 1 AP
42. include ARCS or dV DOSC As an alternative to flown fill ARCS speakers can be stacked on stage preferably close to the subwoofers Other possible front fill enclosures include MTDI 15 MTDI I2 8 or EXI 12 loudspeakers a Stacking Guidelines The stacking system is rated for a maximum of 6 V DOSC elements For this type of installation the precise nature of V DOSCs vertical coverage allows little margin for error The designer must know if the audience is standing or seated the bottom of the array should be higher than the ears of the first rows of the audience and the lowest element tilted downwards by adjusting the BUMPER screwjacks It is also important to keep in mind the one degree difference in angle straps for stacked versus flown systems see Section 2 If the bottom of the array is too low the first rows receive too much SPL and audience members directly in front of the system behave as an acoustic screen for the following rows Ideally the bottom of the array should be slightly above the audience not lower than 2 m or 6 5 ft above floor level with the lowest element tilted downwards as necessary For complete details on stacking procedures please refer to Section 4 1 L ACOUSTICS V DOSC Manual Version 3 2 10 01 57 119 BAD u 7 Y L k k 4 1 F 3 4 a P q Y 1114 j A N M j 3 1 GOOD 1 5 N i F x op p Figure 22 Illustrati
43. measurement equipment is necessary for setting up complex sound systems involving multiple sources especially for doing electronic delay arc processing of subwoofer arrays Additional information that is available related to room acoustics can also be useful for the tuning process for example at various frequencies and waterfall plots can help isolate resonance frequencies for a given room L ACOUSTICS V DOSC Manual Version 3 2 10 01 90 119 5 4 V DOSC OPERATING MODES V DOSC system operating modes can be summarized as follows Stereo 3 way 2 Stereo 3 way plus single or dual mono 2 way fill center cluster and or front fill 3 Stereo 3 way plus stereo 2 way fill stereo down or front fill 4 Stereo 3 way plus separate sub drive plus single or dual mono 2 way fill 5 Stereo 3 way plus separate sub drive plus stereo 2 way fill 6 Stereo 3 way plus 2 way Left Left and Right Right offstage fill 7 Stereo 3 way plus 2 way Left Left and Right Right offstage fill plus dual mono 2 way fill 8 Stereo 3 way plus 2 way Left Left and Right Right offstage fill plus stereo 2 way fill 9 Stereo 3 way plus 3 way Left Left and Right Right offstage fill 10 Stereo 3 way plus 3 way Left Left and Right Right offstage fill plus dual mono 2 way fill 11 Stereo 3 way plus 3 way Left Left and Right Right offstage fill plus stereo 2 way fill 12 Stereo 4 way 13 Stereo 4 way plus single or dual mono 2 way fill center cluster and or
44. of the first V DOSC element The two people on either side of the array then use the side handles to lift the second V DOSC element up towards the first element allowing them to connect the ANGLE straps from the first element to the second element see Fig 36 s t Note If the rear motor is raised slightly higher than the front motor this will tend to close the cabinets automatically making it easier to attach ANGLE straps As a reference attach ANGLE straps from flytrack hole 3 to hole 3 between cabinets to provide the correct interelement spacing When using the 0 75 degree angle strap to obtain 5 5 degrees attach the straps from flytrack hole 3 to 2 Always make sure you have a solid physical mating between the double stud fitting and the flytrack do not hold the plunger out simply place the fitting into the flytrack then slide the fitting into positon and listen for a loud click Physically shake the ANGLE strap to ensure that a secure physical connection has been obtained L ACOUSTICS V DOSC Manual Version 3 2 10 01 77 119 Optional SPACER blocks can also be inserted on each side by attaching the hook and safety on the bungee cord between cabinet handles then pushing the SPACER backwards towards the rear of the enclosures so that they are tightly wedged in between the boxes and all slack is taken out of the ANGLE straps Note Ratchet straps or SPACER blocks are required since as elements are added to the array the weight of th
45. offset by air absorption at large distances in open air situations and by both building material absorption and air absorption indoors resulting in spectrally balanced sound over the largest area possible Since the flat array configuration maximizes energy and intelligibility with distance it should mainly be used for long throw applications or in very reverberant rooms It is also common to use a flat array section at the top of a variable curved array for maximum throw in arena and stadium installations In some cases the upper elements of flown V DOSC arrays are ratchet strapped together in order to provide such a long throw flat section b Curved VDOSC Array A curved V DOSC array stacked or flown is obtained by using ANGLE straps to provide the desired angle between each element and inserting SPACER blocks between adjacent elements to maintain the desired angle If the angle between two adjacent V DOSC elements is smaller than 5 WST criteria are satisfied and the array behaves like a continuous curved radiating ribbon If the angle between elements exceeds 5 WST criteria are no longer valid over the full audio frequency range Practically a larger angle produces neither desirable nor predictable results elements radiate individually and the benefits of collective coupling are lost This is why ANGLE straps are available only up to 5 There are two types of curved V DOSC array constant curvature and variable curvature For
46. outputs 5 and 6 The XTA offers independent limiting for each output with attack times that are variable between 0 3 ms to 90 ms Release times are 4 8 16 or 32 times the attack time and thresholds range from 22 dBu to 10 dBu in dB steps Automatic limiter time constants can be selected where attack and release times are set based on the highpass filter frequency see the DP224 or DP226 manual Output meters are linked to the limiter time constants so that true output metering is displayed All displays are relative to the limit threshold providing a direct indication of available system headroom NOTE XTA treats input memories as separate from program memories presets Make sure that when you recall a new preset all input PEQs and input delays are also reset b BSS FDS 355 FDS 366 Omnidrive Compact Digital Signal Processors The BSS FDS 355 Omnidrive Compact features 3 inputs and 5 outputs with complete routing flexibility while the FDS 366 is a 3 x 6 unit Up to fifty bands of parametric equalization are available depending on the crossover settings and are assignable to inputs or outputs All output channels provide crossover filtering selectable number of parametric eq sections including high and low shelving filters channel delay polarity reverse phase adjustment and limiting Full metering is provided for all inputs and outputs with mute and attenuation controls for all outputs Single or multiple units can be controlled
47. panel return signal from amplifiers to computer REMOTE OUT 4 pin MALE XLR on front panel control signal from computer to amplifiers REMOTE IN 4 pin FEMALE XLR on front panel control signal from computer to amplifiers REMOTE IN 4 pin FEMALE XLR on front panel return signal from amplifiers to computer L ACOUSTICS V DOSC Manual Version 3 2 10 01 101 119 7 5 CO24 CONTROL OUTPUT PANEL LINE ASSIGNMENTS Table 14a CO24 W6 Pin Assignments W6 PIN W6 XLR XLR CACOM CACOM PROCESSOR LOUDSPEAKER CODE 4 RD 2 A B H LETET GND 37 GND A3 1 D MD LETLET GND 31 RED 3 A R 2WAYFLLHF LEFTLEFT 30 GREEN 6 2 P 2 LEFTLEFT 0 p k JL wp r 24 ORANGE 2 B B H LET 23 GND B4 1 B A J H Er 21 GREEN B3 3 B F M j LET 20 B3 2 B E J M LET L 49 BS Jj W Be L p r J L 18 GREEN B2 1 sj zd No 3 ler Hn be MER 1 L6 2 Y Bs 36 ti WIE SUR 2 _ 14 BUE 2 B L Jj SB ee 133 GND Bi 1 B K J SB j LET 12 WHITE B6 3 B R 2WAYFLHF LET 11 BROWN B6 2 B P 2WAYFLHF LET 4 GND 6 1 B N S 2WAYFLHF LET 10 BLUE 3 B U
48. person has great skills and experience with respect to other systems A V DOSC operator unquestionably needs specific training and there are two levels of qualification THE QUALIFIED V DOSC TECHNICIAN QVT The responsibilities of a Qualified V DOSC Technician are equipment preparation system design using ARRAY software on site measurements or from architectural plans system installation rigging assembly cabling system focus preset selection and drive rack configuration system testing tuning and assisting the FOH mix engineer is a sound technician with demonstrated ability who has been chosen for his or her technical expertise by a given V DOSC Network service provider To be included in the official list that is distributed to members of the V DOSC Network the QVT has to meet the following criteria Must be recommended by a recognized CVE or an official representative of the V DOSC Network Must have participated in V DOSC training sessions on theory and rigging THE CERTIFIED V DOSC ENGINEER CVE The higher level of qualification is termed Certified V DOSC Engineer or CVE In addition to satisfying the mission statement for Qualified V DOSC Technicians see above the CVE has further expertise in the areas of sound design and system measurement as well as extensive real world experience with V DOSC The CVE has a deep theoretical understanding of Wavefront Sculpture Technology based systems including V DOSC
49. point for pan adjustment of the flown array Each flying point should be equipped with a chain motor of 0 5T for a 4 element array 1 for 5 to 0 element array 2 0T for an 11 to l6 element array Access is available beneath the flying points i e a flat surface where it is possible to roll V DOSC elements into position preferably from behind the flying location but it is possible to fly when boxes are lined up perpendicular to the fly points eg from the floor along the front of a stage Given the above conditions The first step is to line up all the elements at the flying location while they are still face down on their dollies As a reference for cabinet orientation the stacking runners for the element that is to be at the top of the array should be visible at the flying location Looking down the line of enclosures from the flying location the V DOSC logos on the rear of all cabinets should all be in the correct orientation Once flown the rear panel logos are upside down see Fig 36 a The elements are then mechanically connected together using the rotating legs and U pins Use the locking safety pins to secure all U pins in place see Figs 36 b e Next the BUMPER is placed at the top end of the array The BUMPER is mechanically connected to the top cabinet in the same way that the cabinets are joined together i e by rotating the BUMPER legs into position on the top enclosure and locking them into place using
50. pressure levels reach 105 dBA continuous A weighted and 125 dB SPL peak The only harmless way to reach such levels is to increase the low end since significant increases in the A weighted SPL would eventually become painful for the audience and illegal In general low and high frequency contours result a more mix friendly system for modern music however the influence such a system contour has on your board tapes is a completely different topic for discussion To a large extent response contours are a matter of subjective taste and personal preference that is related to where the mix engineer prefers to set his mix balance on the channel strip or on the main PA Some engineers prefer a built in low end bump in the PA others prefer a flat system and using the warmth of the channel strip on the console Cultural differences can also be a factor as European audiences in general tend to prefer less bass than in the USA For program material with lower overall level requirements speech and classical music for instance alteration of the traditionally flat tonal balance by boosting the low end is not desirable since peak levels occur only during very short musical transients and the Leq is much lower typically 95 dBA or less In fact a prominent bass response would not be accepted from an artistic point of view by most classical performers and music directors for nominal flat response mid high ratios will have to be scale
51. solutions In many cases the answer is dictated by logistics that are venue specific i e sometimes it simply isn t possible to fly PA Stacking onstage lowers the perceived sound image to stage level which is beneficial in small venues Stacking also offers more low frequency SPL due to enhanced floor coupling and since V DOSC has less SPL attenuation from the front to the back of the audience than traditional systems this allows a stacked system to project further In addition for geometric reasons a stacked array can provide more extended vertical coverage than a flown one this can be seen using the ARRAY 2000 spreadsheet and is simply related to the geometry of the audience to be covered For these reasons stacking makes sense in small configurations where only a few elements can optimize both audience coverage and low frequency response Flying is the best solution to achieve uniform sound pressure level and even tonal balance over the entire audience provided that the number of elements arrayed is sufficient to provide the necessary front to rear coverage Flying is also an excellent solution for sightline problems that commonly occur Another practical consideration is that if more than 6 elements are to be arrayed it is necessary to fly them for stability reasons In flown configurations additional speakers are typically added to the array to cover center or front fill requirements Good candidates for this application
52. system Number of V DOSC Cabinets b SB218 Flying Bar Dimension WxHxD 1420 mm x 140 mm x 40 mm 55 7 8 x 5 4 8 x 1 5 8 Weight 12 kg 26 5 Ibs 1420 40 140 O O O O Scale 1 20 1 5 Figure 43 SB218 Flying Bar Line Drawing L ACOUSTICS V DOSC Manual Version 3 2 10 01 100 119 7 4 C024 MD24 LINE ASSIGNMENT SUMMARY W6 OUTPUT CO24 WHIRLWIND PAIR NUMBER O1 BW I Table 13 Whirlwind W6 MASS Connector Input Output Line Assignments W6 PINS XLR ICACOM ASSIGNMENT A ABC A DEF A2 A GHJ A1 A KLM A6 A NPR A5 A STU B4 B ABC B3 B DEF B2 B GHJ B1 KLM B6 B NPR B5 B STU W6 SOCKETS XLR ICACOM ASSIGNMENT C ABC DEF C2 C GHJ C1 C KLM C6 C NPR C5 C STU D4 D3 D DEF D2 D GHJ D1 D KLM D6 D NPR D5 D STU W6 INPUT MD24 WHIRLWIND PAIR NUMBER W6 PINS CACOM ASSIGNMENT C ABC C DEF C GHJ C KLM C NPR C STU D ABC D DEF D GHJ D KLM D NPR D STU W6 SOCKETS CACOM ASSIGNMENT A ABC A DEF A GHJ A KLM A NPR A STU B ABC B DEF B GHJ B KLM B NPR B STU REMOTE OUT M REMOTE IN F REMOTE IN F REMOTE OUT M REMOTE OUT M REMOTE IN F REMOTE IN F REMOTE OUT M NOTE NOTE REMOTE OUT 4 pin MALE XLR on front
53. the array is tilted upwards weight is progressively distributed from the rotating legs to the ANGLE straps As a result the maximum upward tilt angle is approximately 5 degrees Note detailed mechanical load calculations can be performed using ARRAY 2000 software to determine exact array tilt angle limits NOTE A single BUMPER can safely fly an array of up to 16 V DOSC elements Chain motor ratings for each fly point are as follows 0 5T motor per point for a 4 element array 1 0 motor per point for a 5 to I O element array 2 0T motor per point for an Il to 16 element array NOTE Always refer to the mechanical data cells in ARRAY 2000 see Section 2 3 to verify that safe rigging conditions apply with respect to load distribution The BUMPER can also be used for stacking V DOSC In this case the BUMPER is inverted upside down and the first element of the array is installed directly on the BUMPER Since the depth of the BUMPER is larger than that of a single element this allows for better front to rear stability of the L ACOUSTICS V DOSC Manual Version 3 2 10 01 25 119 stacked array Screwjacks can be attached at the four corners of the BUMPER and used to tilt the BUMPER and hence the whole array In this manner the global angle of the array can be adjusted to match coverage requirements When stacking angles between adjacent elements cannot be obtained by gravity and SPACERs are employed in addition to ANGLE straps Alternatively
54. there are mini buildups between and C R that also help to smooth out the centre buildup STAGE Ant STAGE ar gt TIT lt L ACOUSTICS V DOSC Manual Version 3 2 10 01 66 119 L L L R R R i i ee See ee BEEN PN We ee i T4 Figure 29 Subwoofer configuration with electronic arc processing Enter physical location x y coordinates 4 Enter arc radius y coordinate backline 2 Calculate alignment delay x coordinate backline 3 Enter backline delay R arc radius Figure 30 Terminology for the SUB ARC Sheet in ARRAY L ACOUSTICS V DOSC Manual Version 3 2 10 01 67 119 3 5 DELAY SYSTEMS The use of V DOSC in FOH applications provides exceptionally broad coverage over distances that simply cannot be reached with traditional systems This is major benefit of the WST approach Table 10 SPL Comparison Conventional System versus V DOSC Operating in Cylindrical Mode DISTANCE Conventional System V DOSC cylindrical kes A weighted SPL A weighted SPL 96 dB 103 dB 90 dB 100 dB As seen in Table 10 the excellent longthrow capability of V DOSC can oftentimes eliminate the need for a delay system In addition the mix position can be located as far away as 80 m 250 ft from the stage without problems for the FOH engineer However some external conditions such as physical obstacles
55. there is acoustic summation Then turn down amp channel land turn up amp channel 3 and again confirm acoustic summation Repeat the process i e and 2 2 and 3 3 and 4 etc until you have checked all amp channels and all bands for each array If you encounter a polarity problem use a polarity checker to isolate the problem 3 Verify coverage by running low level pink noise through the system excluding subwoofers and walking the room Check the coverage down front and at the back of the venue Perform any required trim and angle adjustments if necessary 4 Using your preferred measurement system at the mix position compare Left versus Right frequency response channel by channel as a final system check All responses should be identical within dB except for the high band where larger deviations are acceptable 2 to 3 dB Beware of wind effects which can dramatically affect your measurements 5 Typically the subwoofers act as an overall time reference for the complete system so the next step is to time align the subwoofers to the main arrays L ACOUSTICS V DOSC Manual Version 3 2 10 01 88 119 If a time domain measurement system MLSSA TDS SIM SMAART or SpectraFOO is not available use a laser rangefinder to measure the geometric difference between the main array and the subs Adjust the subwoofer delay to correspond to the geometrically determined delay as a starting point Place a microphone on the floor halfway between t
56. using ARRAY 2000 2 5 2 5 gt je 20 80m i 4 11 05 105 1 x E m ow A M N 6 7m 6 7m 40 70 N 40 70 WRT MAIN wo WRI MAIN w y B z 5 L a s E LS E o 05 mo 08 x Typical Rigging Plot for a LL L R RR System L ACOUSTICS V DOSC Manual Version 3 2 10 01 56 119 b Achieving Optimum Coverage Using the isocontour drawn on a blueprint or the data provided in ARRAY 2000 H ISOCONTOUR it is easy to achieve correct horizontal coverage for a complete system consisting of several V DOSC arrays Parameters for each array such as spatial coordinates axial direction are chosen by the sound designer and entered in ARRAY 2000 with respect to the basic geometry of the audience The displayed horizontal isocontours should overlap to a certain extent and cover the majority of the audience for the amount of overlap see Section 3 3 b for a discussion of the tradeoffs between stereo perception and intelligibility The remaining uncovered areas should be covered with smaller 2 way fill speakers such as ARCS or dV DOSC Alternatively in some cases a distributed front fill system using 15 MTDII2 MTDI08a or EXII2 loudspeakers can be highly effective in complementing V DOSC system coverage 3 2 STACKED OR FLOWN Although flown systems are generally preferred by most sound engineers there are good arguments to support both
57. via PC using Soundbench software Up to 60 internal program locations are available and preset or system software updates can be downloaded via PC card or L ACOUSTICS V DOSC Manual Version 3 2 10 01 34 119 from a PC via RS232 ports Multiple levels of password protection are also available allowing BSS processors to be configured as a fully secure unit For exact details regarding operation please refer to the appropriate BSS Operating Instruction Manual BSS output channel limiters can be set to fast medium or slow 366 or normal fast 355 depending on the desired attack and release times Limiter detection circuitry is centered on the mid frequency for each band and threshold units of either dBu or mV can be selected Limiters can also be disabled in this case the red OVER indicator is illuminated on the disabled channel to serve as a warning Even when limiters are disabled the threshold setting determines the output meter sensitivity i e the yellow limit indicator on the display corresponds to the limiter threshold c General Guidelines Regarding System Protection As supplied by L ACOUSTICS limit thresholds for both XTA and BSS Processors are initially set at 9 9 9 and 9 dBu for sub low mid and high channels respectively These thresholds are matched to the input sensitivity of the L ACOUSTICS LA 48 9 5 dBu so that system protection is performed by a combination of the limiting circuits of both amplifier and digital
58. 0 40 50 60 70 80 Figure 31 Long amp Narrow Audience Format flat L ACOUSTICS V DOSC Manual Version 3 2 10 01 69 119 b Wide Audience Format HORIZONTAL ISOCONTOUR 80 rated at 102 dB A weigted 70 or 114 dBSPL 60 50 1 A2 A3 A4 m Elts number 8 8 5 5 20 12 12 40 40 10 AUDIENCE CONTOUR 1 CONTOUR 2 20 30 100 110 120 130 140 150 40 50 60 70 80 Figure 32 Wide Audience Format Foxwoods Casino Installation L ACOUSTICS V DOSC Manual Version 3 2 10 01 70 119 c Stadium or Large Scale Outdoor Festival Format HORIZONTAL ISOCONTOUR 80 rated at 102 dB A weigted 70 or 114 dBSPL Elts number dBV input AUDIENCE CONTOUR 1 CONTOUR 2 20 30 0 110 120 130 140 150 40 50 60 70 80 Figure 33 Stadium or Large Scale Outdoor Festival Format L ACOUSTICS V DOSC Manual Version 3 2 10 01 71 119 d Arena Format Steep Slope m B B BE HORIZONTAL ISOCONTOUR 80 rated at 102 dB A weigted 70 or 114 dBSPL 60 50 1 2 A4 Elts number 12 12 dBV input 4 4 30 15 15 40 12 12 0 0 5 AUDIENCE CONTOUR 1 CONTOUR 2 20 X Y X Y 0 60 idu 0 0 60 130 70 130 Figure 34 Arena Format 0 0 120 130 140 150 30 40 50
59. 2096 error When the front motor load goes to zero Minimum Site Angle is displayed 4 2 LEG STRESS refers to the stress on the top enclosure s rotating legs balanciers and is accurate within 2096 error NOTE the effect of rear ratchet strapping is not taken into account 5 2 ANGLE STRESS refers to the stress on the top enclosure BUMP angle straps and is accurate within 20 error If the angle strap load rating is exceeded there is WARNING indication Note the effect of additional rear ratchet strapping is not taken into account IF YOU ARE APPROACHING A WARNING INDICATION DO NOT OVERTIGHTEN RATCHET STRAPS UNDER ANY CIRCUMSTANCES USE SPACER BLOCKS INSTEAD For more details on ratchet strap issues please refer to Section 4 2 H ISOCONTOUR SHEET The H ISOCONTOUR sheet is used to check horizontal coverage by mapping a projection of the horizontal isocontour of the defined V DOSC and dV DOSC arrays onto the user defined audience area By matching horizontal coverage to the audience area H ISOCONTOUR can be used to check array placement and aiming as well as to determine whether offstage fill front fill or center cluster arrays are required Two audience areas can be defined and the coverage of up to four arrays displayed 2x V DOSC 2x dV DOSC Calculation assumptions include 3 dB SPL reduction with doubling of distance i e arrays have been designed for constant spacing using their respective Cutview sheets doubling the number of
60. 218 Grille Foam SB218 Front Grille V DOSC Grille Foam V DOSC Front Grille Neoprene glue for grille foam attachment Brown paint packaged by 10 kg Dust filter clips for LA 48 Dust filters for LA 48 Rear support kit for LA 48 amplifier L ACOUSTICS V DOSC Manual Version 3 2 CC 19 EM 19 FF CC4F CC 4 ER CC 25SUBDM CC 3 SUBDM CA GOUP45 CA EL45 CA GOUP6 CA EL6 CA POIG CA ROL CD AIMAN MC DOAXF 2 MP DORAIL G MP DORAIL D CA MAN22 CA MANBI CA PION3 CM SUB218 99 MC GRSUB218 CM DOSC 99 MC GRDOSC CD COLNEO CD TEXTURE APCLIP APFILT APSUP 10 01 94 119 6 4 RECOMMENDED INSTALLATION TOOLS Digital Inclinometer Digital Protractor PRO 3600 or equivalent Remote Digital Inclinometer LUCAS ANGLESTAR Laser Level Device Laserline XPRO or equivalent Laser Rangefinder Binoculars Bushnell Yardage Pro 600 or equivalent 2x 20 m 50 ft tape measures Polarity Checker PC 80 MK I I SCV Audio BSS or equivalent Portable computer with Excel for ARRAY 2000 BSS Soundbench XTA Audiocore and MLSSA or TEF or SMAART LIVE Mac users try Spectrafoo OPTIONAL INSTALLATION TOOLS Analog Inclimoter SUUNTO PM 5 360PC Laser rangefinder measurement system Leica Disto Classic BFT2 rifle site GLI22 level tripod Laser range finder Polarity checker Figure 39 Recommended Installation Tools L ACOUSTICS V DOSC Manual Version 3 2 10 01 95 11
61. 9 7 SPECIFICATIONS 7 1 V DOSC ELEMENT SPECIFICATIONS The specifications for one individual V DOSC element are given below These individual element specifications are not relevant to V DOSC system performance since overall system behavior is the net result of the complex acoustical coupling between all elements of the array Frequency response 3 dB Full system bandwidth with SB218 Power rating pink noise LF MF HF Horizontal Coverage Angle Vertical Coverage Angle System Data enclosure 2 enclosures 4 enclosures LF MF HF Material Finish Grill Features Dimension WxHxD Weight 50 Hz 18 kHz 25 Hz 18 kHz Impedance 2x 375 W RMS 8 ohms 600 W RMS 8 ohms 200 W RMS 16 ohms 90 6 dB points symmetrical about main axis 70 3 dB points symmetrical about main axis not defined for one element Continuous SPL Continuous SPL flat array maximum curvature 134 dB 134 dB 140 dB 139 dB 5 degrees vertical coverage 146 dB 43 dB 15 degrees vertical coverage 2 x 15 weather resistant loudspeaker 3 voice coil bass reflex 4 x 7 weather resistant loudspeaker kevlar cone bass reflex 2 x 1 4 compression driver mounted on patented DOSC waveguide Baltic birch plywood Sealed screwed and rabbeted angles internally braced cabinet construction Maroon gray Black epoxy coated perforated steel with acoustically transparent foam Integrated flying hardware and han
62. Audienee Formatiu unus aus Des 7 c Stadium or Large Scale Outdoor Festival Format 72 d Arena Format Steep ri t a dad debebam dtu 73 e Invisible Configuration System Located Behind the Stage 74 4 INSTALLATION PROCEDURES 1 E en 75 AA STACKEDSISTEN sensationell 75 a Stacking and onneeting a ee 75 76 4 2 INSTALLATION OF A FLOWN SYS TEM EEE 77 Flying and Connecting tst odium idest hei then div eius 77 b Frim and Angle Adjustment u a ae EL ee 79 CENNE Ampliier RACKS oie rat eb dive 86 d Sale Rules ns m series 86 5 V DOSC SYSTEM OPERATION 3 ese een pe BE ee 87 5 1 SUBJECTIVE LISTENING AND TONAL BALANCE au EL 87 3 2 MEASUREMENT EROGED RE an nee ee else 88 a Measurement Caveats nn er Reale 88 b Step By Step Tuning Procedure 89 c SIM MLSSA TDS SMAART SpectraFOO HMeasurements 9 5 4 V DOSG OPERATING MODES nun a eee beste pest da eons 92 6 MAINTENANCE AND INSTALLATION TOOL S
63. CD LOAD PEAK RECD LOAD PEAK REC D LOW 8 375 1500 750 4 750 3000 1500 2 7 1125 4500 2250 8 600 2400 1200 4 1200 4800 2400 2 7 1800 7200 3600 HIGH l6 200 800 800 8 400 1600 1600 5 3 600 2400 2400 Table 4 Recommended Power and Amplifier Power Ratings EIA IkHz 196 THD LOAD Section MIN Section CROWN CROWN ohms REC D REC D MA5000 MA5002 2 L ACOUSTICS V DOSC Manual Version 3 2 10 01 33 119 1 9 V DOSC CONTROL Four digital signal processing units are currently supported and specified by L ACOUSTICS for controlling the V DOSC system XTA DP 226 DP 224 and BSS FDS 355 Omnidrive Compact FDS 366 Omnidrive Compact Plus XTA or BSS processors are supplied with proprietary presets that are intended for specific array configurations Since the XTA DP 226 is a 2 input by 6 output unit the DP224 is 2 x 4 the BSS FDS 355 is 3 x 5 and the FDS 366 is 3 x 6 exact internal wiring of your FOH drive rack and digital processor channel assignments will vary depending on the selected processor and the application Various operating modes processor channel assignments and MULTI line assignments are described in detail below for the various processors Carefully consider your flexibility requirements before selecting the number and type of processors to specify NOTE Whichever processor is used MULTI line assignments must remain standard to allow for system compatibility Failure to follow M
64. D IDENTIFICATION OF THE COMPONENTS OF THE SYSTEM a Universal V DOSC Standard A V DOSC system is a complete self contained FOH sound reinforcement system consisting of loudspeaker enclosures amplifier racks flying hardware dedicated control and signal processing packaging cables and connectors V DOSC system elements have been carefully selected by L ACOUSTICS for their specific quality and long term reliability Together the elements of the system form a Universal Standard for V DOSC The benefits of a standard version of the V DOSC system include Total compatibility between all V DOSC partners for cross rental purposes Long term amp common experience shared by all QVTs and CVEs Very flexible packaging which is not dedicated to one specific application High standards of quality control ensuring that V DOSC system performance is consistent for all Network Partners world wide resulting in enhanced end user confidence The V DOSC system does not include chain motors mains distribution or external handling gear nor does it include upstream signal mixing and processing equipment In general terms the V DOSC system is capable of producing sound from a line level signal in any concert situation System block diagrams are presented below to provide an overview of system connection and signal flow This is followed by an identification of the individual components of the system and more detailed descriptions in Sect
65. DOSC in sound design whether for touring or fixed installation Understanding the concepts behind V DOSC and Wavefront Sculpture Technology is just as important as learning the many operational details related in this manual the more you understand the big picture the more effectively you will use V DOSC As you will see V DOSC is a complete system approach starting from the basic question of how to effectively couple sound sources then including all aspects of sound design system installation rigging cabling signal distribution digital control tuning and performance prediction This turnkey system approach allows for accurate and predictable results however in order to achieve the best results you need to understand the concepts behind how the system works Since V DOSC is unique in many ways this means that specialized training is absolutely necessary Apart from sound quality the system design approach and ergonomics there are many benefits to V DOSC Many of you readers are already aware of these benefits otherwise they will become apparent throughout the course of this manual 0 1 WAVEFRONT SCULPTURE TECHNOLOGY FUNDAMENTALS a The Sound Reinforcement Problem The trend in sound reinforcement has been to increase both the actual SPL during concerts and the size of the audience to be covered This inevitably leads to an increased number of loudspeakers since more powerful single loudspeakers would reach such sizes and weigh
66. GA 1 GA O T MAP AC AF JA VN 135 BSS FDS 355 Presets Table 6 38 119 10 01 L ACOUSTICS V DOSC Manual Version 3 2 BSS FDS 366 VERSION 6 0801 PRESETS FOR V DOSC 91 v dis 7 95 8 IH 244 8 IH 244 8 IH 244 8 IH Sou IH S2uv 9 1 v ars 81245 vL 9 9758 2 95 1 v 916 81785 Z1 x ANS 8 1295 11 v 9 5 81245 O15253 ans 9 5 x H Suv 015254 ans 5 O15249 d 915 5 Y H 244 015254 ans 9 5 OlS2uv 8 ans 81795 v IH 24 015254 7 9115 8 295 SF 144 tr tr OF O15249 8 ans 81785 x IH Suv 015254 975 8 cas 2 01524 8 524 9 O15238 v H SO uv 41015234 DOSY 8 IH 58 9 01524 WI H SO uv 9 0152 7 x IH 9 O12SOQ AP gris AP punos 8 785 x IH 2SOC AP O1 2500 AP GANS AP 7 9 gt 5 x O12SO0Q AP x UNO gris AP g IHO2SOQAP d 1 5 8 ans 81295 y IH 2SOQ 9 O12SOQAP v 9158 1295 AP werde 9 IH DSOQAP d 125 8 ans 812485 9 5 v O1DS00 AP 9158 1295 vt 00 19 g IH 2SOQ P d 1 5 8 818 81295 9 IH DSOG AP v O1DS00 AP 9 9158 1295 gt nc g IH 2SOQ P 8 1 5 8 ans 81285 9 5 s 125 x 9158 1295 4 mt nc AP AP SE piHosog P WorssocApr Wasap ic
67. GIIY MWYI I I I IW6 I I WZ IIU IWM IWKGIIIIII I IIIIICI IW I lt II I I IO IIKQ6SW I I II I S ZI IWI IIIIII WIIIIIIIIII OEIWIVSSSSSS3 q Tin gv di IH SDM di vi IH vi Sk wins ouou Ae q TIN d IH 2Mv q O 15 v IH S2 T OT SIHT 00 5 uns 094918 Aeg AAF SHY re ea g PUND 3208 ans y OTIT AP gng AP 596 Er 9 812015 AAF 9 PUNGIDS 3208 11719 y OISSOCAB y uve gng AP 81796 zr 9 1 O 181 s 9 BUNGIE 8 15 zi ris DSOC AP y OTIT AP 4 gng AP WIPUNGID 9 1 9 15 g punoo 9 718 v TI z H 28oQ AP y OISSOQAP V grs AP YI punoo or q oy OT Uns AP AAP a i R T q IH 28OQ AP 8 21 OSO CHAP 9 ans B 179 OT DSOCAP 7 ANS B 000 81205 ME q IH DS800 AP 8 O 1 DSOC AP 9 ans 81798 7 H 29OC AP OT DSC CHAP 7 ANS 812 95 Be ss Is AEM O 1 SIGS AE d IH 28OQ AP 8 O 1 SO CHAP 9 AIH 28OC AP OT DSOCAP 7 ee H SAP 08 AE q IH D800 AP O 1 DSOC AP 8 gns AP IH 28OC AP OT DSC CHAP 7 INS AP of 0000 SAP 08 q IH 28OQ AP O 1 SO CHAP 8 griS AP 7
68. Hz Although 4W presets do not utilize the full potential of the V DOSC low section in producing maximum low frequency output in some cases 4W programs may provide mix engineers with a more traditional 4 way system that is more familiar to them For 3 way stereo V DOSC 3WX presets the low HPF is extended to 40 Hz and shelving eq is introduced Note either V DOSC 3W 50 Hz HPF or V DOSC 3WX presets should be useful in conjunction with separate AUX drive processing for the sub section To summarize the main differences in low section processing for V DOSC presets PRESET Low Section HPF X 27 Hz LR24 4W 80 Hz LR24 3W 50 Hz LR24 3WX 40 Hz BWI2 shelving eq The Version 6 preset release has been optimized for a 1 5 cabinet ratio of V DOSC SB218 for example 3 2 6 4 9 6 12 8 15 10 Recommended gain scaling procedures for different cabinet ratios are summarized as follows V DOSC SB218 SUB LOW Cabinet Ratio Output Gain Output Gain 2 1 6 dB 0 dB 1 5 4 4 dB lt recommended ratio standard scaling 4 dB 4 dB Following this gain scaling procedure according to cabinet ratio will provide the same low end spectral contour for V DOSC 4W and X presets The mid and high sections should then be scaled up down equally according to the size of the array in order to compensate for low frequency coupling effects and provide the overall desired tonal balance see Chapter 5 re tuning As a starting point output channel
69. IGHT 9 BROWN D5 2 D T 2WAYFLLLF RIGHT RIGHT 8 GD p 1 D S 2WAYFLLLE RIGHT RIGHT IN 1 YELLOW EN db 2 NE 3 EA NENNEN lud 2 NEN sss L ACOUSTICS V DOSC Manual Version 3 2 10 01 103 119 7 6 MD24 MULTIDISTRO PANEL LINE ASSIGNMENTS Table 15a MD24 W6 Pin Assignments W6 PIN W6 CACOM CACOM PROCESSOR LOUDSPEAKER COLOR CHANNEL PIN CHANNEL ARRAY CODE 42 BACK C HE RH _ 44 wE C B H RH 40 GND C J A HE RH BLACK C F MD RH 38 BLUE C E MD RH 3 D MD RH __ 36 Back Fr RIGHT 35 BROWN C H _ RH 34 G LF RGH 33 RD C M SUB RH 32 wE C L SB RIGHT 22 GND K SUB RGH 31 RD C R 2WAYFLLHF RICHT 30 BLUE P 2WAYFLLHF RIGHT 20 GND N 2WAYFLLHF RIGHT 28 RED U 2WAYFLLLE RIGHT 27 BROWN T 2WAYFLLLE 20 S 2WAYFLLLE RIGHT 25 GREEN D C H RIHTRIGHT 22 wE D B 22 GND D A HF RIHFRGH 21 GREEN D F MD 20 uow D E MD 19 GND D D 18 GREEN D J LF RIHFRGH 177 ORANGE D H LF RIHFRGH 16
70. L ACOUSTICS V DOSC Manual Version 3 2 SUBWOOFER ARRAYS with electronic arc processing Hd 92 119 6 MAINTENANCE AND INSTALLATION TOOLS 6 1 RECOMMENDED MAINTENANCE PROCEDURES Regular maintenance procedures monthly include component sweep using sine wave generator or other suitable test system and polarity check to ensure that all speakers and drivers are in good working order tighten all ANGLE strap shackles and inspect all double stud fittings cable continuity test MULTI AMP LINK CROSS LINK LINK BREAKOUT LINK SPLIT LINK EXTEND V CABLE V LINK F CABLE F LINK SUB cables clean power amplifier filters verify crossover presets are correct and up to date Periodic maintenance procedures every 6 12 months include tighten dolley locator pins and all external fasteners on V DOSC and SB218 enclosures tighten high frequency diaphragm mounting fasteners inspect all rigging components for wear and replace as necessary i e rotating legs rotating leg pins U pins rotating leg covers flytrack sections angle strap fittings inspect wiring harnesses internal connections for all panels Occasional as necessary maintenance procedures include refoam grilles repaint cabinets replace stacking runners replace protective covers for rotating legs 6 2 RECOMMENDED MAINTENANCE TOOLS Miscellaneous Tools adjustable pliers rubber mallet sidecutters wire stripper soldering iron digital voltmeter DVM break
71. OMB connector for powering 2 way fill enclosures DO2W allows direct connection to the panel DOFILL is used with V CABLE L ACOUSTICS V DOSC Manual Version 3 2 10 01 20 119 V DOSC SB 218 k PANEL PADO4 AMP RACK RKI2U a LEFT n Fr F N Aar eal Bipa pu 1 MULTI DISTRO MD24 CONTROL OUTPUT CO24 gt ANGLE STRAPS BUMPER2 L ACOUSTICS V DOSC Manual Version 3 2 10 01 21 119 SB 218 FLYING BAR DELTA PLATE SPACER LINK DOM2 CROSS LINK DOM30 LINK EXTEND DOMP LINK BREAKOUT DOMF V CABLE DO7 V LINK CABLE DO 7 L ACOUSTICS V DOSC Manual Version 3 2 10 01 22 119 F CABLE DO7 F LINK CABLE DO 7 DOFILL DO2W SUB CABLE DOSUB SUB EXTENSION DOIOP Figure 5 V DOSC System Parts and Accessories L ACOUSTICS V DOSC Manual Version 3 2 10 01 23 119 1 2 V DOSC ELEMENT SPECIFICATIONS STACKING RUNNER RECESS Dimension WxHxD 300mm x 434mm x 565mm 51 2 x 17 1 x 22 2 Weight 108 kg 238 Ibs 9 5 kg 21 16 with dolley FLYTRACK d il NI 1 AXE FIXE U PIN ROTATING LEG BALANCIER Figure 6 V DOSC Element Front and Rear Views The V DOSC element is a full range 3 way enclosure which is designed to be vertically arrayed and forms the core of the V DOSC system It embodies Wavefront Sculpture Technology an
72. OTE L ACOUSTICS does not support all operating modes as standard Custom presets for specific operating modes and different fill enclosure combinations are available from L ACOUSTICS by special order L ACOUSTICS V DOSC Manual Version 3 2 10 01 91 119 LEFT LEFT ARRAY LEFT ARRAY 3 WAY V DOSC or 2 WAY ARCS 3 WAY V DOSC 2 WAY DOWNFILL DV DOSC or ARCS 2 WAY DOWNFILL DV DOSC or ARCS i CENTER CLUSTER 2 WAY ARCS STEREO 2 WAY FRONT FILL ARCS DISTRIBUTED MONO 2 WAY FRONT FILL ARCS MTDI I5a I2 108 or EXI 12 CENTER SUBWOOFER LINE ARRAY with or without electronic arc processing RIGHT ARRAY RIGHT RIGHT ARRAY 3 WAY V DOSC or 2 WAY ARCS 2 WAY DOWNFILL DV DOSC or ARCS 2 WAY DOWNFILL DV DOSC or ARCS 3 WAY V DOSC m mM m Figure 37 Array Elements of 3 Way System Design LEFT LEFT ARRAY LEFT ARRAY 3 WAY V DOSC or 2 WAY ARCS 3 WAY V DOSC 2 WAY DOWNFILL DV DOSC or ARCS 2 WAY DOWNFILL DV DOSC or ARCS CENTER CLUSTER 2 WAY ARCS STEREO 2 WAY FRONT FILL ARCS DISTRIBUTED MONO 2 WAY FRONT FILL ARCS MTDI I5a MTDI I2 108 or EXI 12 RIGHT ARRAY RIGHT RIGHT ARRAY 3 WAY V DOSC or 2 WAY ARCS 2 WAY DOWNFILL DV DOSC or ARCS _ 2 WAY DOWNFILL DV DOSC or ARCS 3 WAY V DOSC he Figure 38 Array Elements of 4 Way System Design
73. Presets and preset updates are available directly from L ACOUSTICS headquarters in France or from Cox Audio Engineering in the U S L ACOUSTICS maintains a library of stock presets for both XTA and BSS processors to support approved amplifiers for a variety of operating modes and cabinet combinations Custom presets are available on a special order basis and there is a standard price per preset in order to cover custom engineering costs b General Description of V DOSC Presets The selection of one preset over another depends on many parameters including the array configuration musical program and personal taste of the sound engineer In general terms LO L ACOUSTICS V DOSC Manual Version 3 2 10 01 36 119 presets are the smoothest while presets are brighter LO and HI refer to differences in the amount of HF shelving equalization applied to the high channel Whenever there is an X in the preset name something is extended For V DOSC X presets the sub LPF is extended higher and the low HPF is extended lower the operating bandwidth for both sections is 27 200 Hz For X presets the subwoofers are intended to work in combination with the low section of the main V DOSC array in 4 way mode when the subwoofers are physically very close to the V DOSC array and act as a low frequency eXtension of the system For 4W presets the subwoofer channel is low pass filtered at 80 Hz and the V DOSC low channel is high pass filtered at 80
74. R for each array is terminated in a line that is referenced to where coverage starts for the bottom element Therefore H ISOCONTOUR gives a direct indication as to the areas where coverage is lacking and offstage fill center fill or delay clusters are required The overlap between L R arrays also gives an indication as to which portions of the audience will experience stereo imaging Note At this time it is not possible to properly simulate the transition between the dV DOSC to V DOSC isocontours when dV DOSC is used for downfill or upfill with V DOSC L ACOUSTICS V DOSC Manual Version 3 2 10 01 54 119 ARRAY 2000 SPREADSHEET CALCULATION EXAMPLE V DOSC ARRAY CONFIGURATION WAVEFRONT SCULPTURE PREDICTION 30 AUDIENCE GEOMETRY Cutuiew 7 SEEN Angle Site Wavepath SPL ARRAY GEOMETRICAL DATA COMMENTS Overall Depth of Array x dim 1 98 m ANGLEs available Overall Height of Array z dim x 1 0 75 13 20 30 40 55 Elevation Z1 Section X2 50 0 Elevation Continuous SPL 1 element 1m Continuous SPL per ARRAY 115 dB MECHANICAL DATA Gravity abcissa I of Elernents Elevation _ Constant Directivity above F2 359 Hz Possible Beaming at 2 Angle stress 384 kg Autofocus Adjust CUTVIEW SHEET HORIZONTAL ISOCONTOUR ARRAYS Isocontour at distance m Console output signal dBu X location m Y location m Azimuth angle deg Headroo
75. S55 present 38 Table 7 BSS FDS 366 Presets nn ae u ei 39 TablE8 XATA DP224PreseiSkuu mk ee ie amt 40 Table 9 X TA DP 226 Presets ee i bride EV 41 Table 10 SPL Comparison Conventional System versus V DOSC Operating in Cylindrical Mode 69 Table Strap Values irn 76 Table 12 Weights for flown V DOSC system 101 Table 13 Whirlwind W6 MASS Connector Input Output Line 102 Fable 19 CO24 W6 Pin Assienments 103 Table 14b CO24 W6 Socket Assignments 104 Table MD24 VV6 PIDASSISBETIBES 105 Table 5511024 V6 Socket Assisnmens nsi edo ee a 106 Table 16 Border in m Between Cylindrical Fresnel and Spherical Fraunhofer Zones 117 Table 17 Dv Vertical Coverage Angle in the Farfield Region 17 L ACOUSTICS V DOSC Manual Version 3 2 10 01 8 119 0 INTRODUCTION The V DOSC sound reinforcement system is different We hope this manual will help you to appreciate why and to understand the basic principles behind how the system works Understanding these principles will help you to optimally use V
76. SOCONTOUR IN THE HORIZONTAL 45 a Horizontal Coverage Angle of a V DOSC 2 0 01 1 00 00000000000000000005000000000000034 45 b Effective Coverage the Horizontal Plane 45 2 2 WAVEFRONT SCULPTURE IN THE VERTICAL PLANE tto ti ba o E o p Up Sae ino ter tb 47 Fat Freuen else 47 b Gurved V DOSC an e v ceste inneres 47 c Constant Curvature V DOSC Array ee u ea dud 48 Variable Curvature Array u L ea 49 2 3 COVERAGE PREDICTIONS USING ARRAY 2000 22 12 021 2 400 000 00000000000000000000000000400800000004 49 CUTVIEW Sheets ARRAY ARRAY2 dV ARRAY 2 eene nnne nnns 50 E 50 b Optimization Procedure uuu ae 5 M iuo idi bia Tc 52 L ACOUSTICS V DOSC Manual Version 3 2 10 01 4 119 HI ISOEONTOUR AJ DE 54 Input dte cour o ler ski 55 b Optimization Proced re u u uuu e ee 55 a ME NL 55 ARRAY 2000 Spreadsheet Calculation Example 56 3 ELEMENTS OF SOUND DESIGN u es ee vere diee ee 57 MULTIPLE ARRAY CONCEP TS aan a nu 57 Reducing Array Interaction ae 57 b Achieving Optimum Co
77. T data are provided for more conventional products manufactured by L ACOUSTICS We are currently working with the developers of room acoustics modelling software packages in order to provide WST based system simulation When curved V DOSC arrays are employed there is a combination of cylindrical and spherical propagation This combined propagation together with the actual shape of the audience allows the wavefield to be focused so that tonal balance and sound pressure levels are evenly distributed throughout the listening area Although pure cylindrical wave propagation is not always in effect 3 dB reduction with doubling of distance can still be obtained along with extension of the nearfield this is the benefit of WST and also the reason why correct focus of the system on the audience area is SO important Psychoacoustically nearfield extension allows one to walk a considerable distance from a V DOSC system with only a small difference in SPL due to the system s unconventional attenuation rate Effectively more of the audience experiences nearfield listening enjoying higher fidelity improved stereo imaging and exceptional clarity Subjectively the loudspeakers seem much closer and the sound is in your face Image localization is towards the action on stage not the loudspeaker arrays Practically this extension of the nearfield means that extreme sound pressure levels are not required close to the system in order to provide acceptable SPLs
78. ULTI standards may result in damage to speaker components of the V DOSC system ALWAYS REFER TO THE PRESET DESCRIPTION SHEET FOR YOUR PROCESSOR WHEN SELECTING PRESETS AND CONFIGURING THE DRIVE RACK a XTA DP224 DP226 Digital Signal Processors The XTA DP226 features 2 inputs and 6 outputs while the DP224 is 2 in x 4 out Both inputs have 8 bands of parametric equalization system predelay and gain control All outputs feature crossover fileers 5 band parametric equalizer high and low shelving filters channel delay and limiting Full input output metering is provided with individual channel mute and access buttons Single or multiple XTA units can be controlled via PC using XTA s AudioCore windows software For operational details for either unit please refer to their respective XTA Operating Instruction Manual The DP226 can be configured in 5 basic modes 3x 2 way left right and mono sum stereo 3 way mono 4 way mono 5 way and mono 6 way For 3 way stereo operation only one XTA processor is required For 4 way stereo operation two XTA processors are required Additional outputs 5 and 6 can then be used for processing of 2 way fill enclosures such as dV DOSC or ARCS For mono fill applications outputs 5 and 6 can be derived from the left right sum allowing for the operation of two independent mono 2 way fill clusters e g flown center fill plus front fill For stereo applications 2 way front or down fill systems can be operated using
79. V DOSC OPERATOR MANUAL L ACOUSTICS V DOSC Manual Version 3 2 10 01 2 119 FOREWORD This manual is intended for Qualified V DOSC Technicians and Certified V DOSC Engineers who are responsible for the set up operation and maintenance of V DOSC systems It is also intended to provide interested sound engineers designers consultants and installers with the information they require regarding the fundamental principles of Wavefront Sculpture Technology and how these principles are embodied within the V DOSC sound reinforcement system V DOSC specifications installation procedures and general guidelines for sound design are also discussed in this document MANUAL ORGANIZATION The Introduction gives a brief presentation of the V DOSC system and explains why specialized training is absolutely necessary to set up and effectively use V DOSC Chapter presents the fundamentals of Wavefront Sculpture Technology and introduces the elements of the V DOSC system standard Chapter 2 describes V DOSC array performance and coverage prediction Chapter 3 discusses elements of sound design and suggested array configurations Chapter 4 gives detailed procedures for stacking and flying V DOSC Chapter 5 describes system operation including tuning operating modes and preset selection Chapter 6 lists recommended installation and maintenance tools Chapter 7 gives detailed specifications for all elements of the V DOSC system Finally the Appe
80. XLR COLOR XLR PIN CH AMP OUT SPEAKON COLOR 3 WAY 2 WAY en RK12 Amplifier Rack Wiring Diagram for PADO4 LARGO MIF l C Q Bah itu ses FF PPP gt C L ACOUSTICS V DOSC Manual Version 3 2 10 01 CHANNEL A BROWN XLR Input BLUE Speakon Output VIOLET XLR Input GREEN Speaken Output WHITE XLR Input RED Speakon Output ORANGE XLR Input YELLOW Speakon Output 31 119 Table 2 PADO2 Wiring Chart PAD 02 COMB PANEL AMPLIFIER WIRING CHANNEL ASSIGNMENTS 19 WIRING COMB WIRING CHANNEL A SUB D 37 TO AMPLIFIER TO SPEAKER CONNECTOR WIRING AMP CHANNEL ASSIGNMENT LINE IN SIGNAL CHANNEL SUB 0 37 SUB 0 37 SIGNAL XLR COLOR XLR PIN AMP SPEAKON COLOR sway sus zwar 14 14 23 26 gnd 1 HF 15 15 24 27 BROWN 2 1 48 1 BLUE SUB HF FILL A AMP 1 CH A CHA AMP 1 CHA 4 1 MF 5 VIOLET 2 1 48 2 GREEN LF FILL A G AMP 2 CH A 3 CH A AMP 2 CH A 7 and 1 LF 27 WHITE 2 LOW1 HF FILL AMP
81. a separate fly point is required and you should be careful to observe safe rigging practices according to your given situation d Safety Rules CAUTION THE FLYING SYSTEM IS RATED FOR A MAXIMUM OF 16 V DOSC 15 V DOSC 3 dV DOSC or 14 V DOSC 6 dV DOSC DO NOT FLY ANY MORE THAN THIS NUMBER ELEMENTS FROM A SINGLE BUMPER ASSEMBLY All rigging should be performed by certified trained rigging experts Proper chain motor installation and operation is absolutely necessary under all circumstances L ACOUSTICS recommends the use of safeties at all times Chain motor ratings for each fly point are as follows 0 5T motor per point for a 4 element array motor per point for a 5 to IO element array 2 0T motor per point 11 to l6 element array For additional safety factor bridling using two steel slings four shackles and one pear ring front and rear is recommended when flying 11 16 element arrays Always refer to the MECHANICAL DATA cells in ARRAY 2000 to ensure that safe rigging conditions apply to the designed system before installation Always be sure that the immediate area is clear of people and obstacles whenever raising or lowering the array Announce in a loud voice whenever the array is being moved to get people s attention Always look up while moving the array to be sure that movement remains unimpeded and to check cable tension Once flown to trim and correctly angled remove motor control cables so that the a
82. al wave expands in the horizontal dimension only and is defined by the section of a vertical cylinder over a predictable distance The height of this section matches the height of the array try to visualize a 90 cheese wedge The overall vertical coverage angle of the array is defined by the top wall of the top enclosure of the array and the bottom wall of the bottom enclosure According to the Fresnel description of wavefields a cylindrical wavefield expands from a source over a certain distance then becomes a classical spherical wavefield Detailed analysis shows that a flat V DOSC array radiates a spherical wavefront at the lowest frequencies and a cylindrical wavefront at higher frequencies at any location within its coverage window The boundary between the cylindrical wavefield and the spherical wavefield is both frequency and height dependent see Appendices 5 and 6 for full theoretical details In spherical mode the wavefront expands in two dimensions thus producing a SPL attenuation of 6 dB with doubling of distance In cylindrical mode the wavefront expands linearly with distance thus producing only 3 dB of attenuation when doubling the distance The net result is that at large distances the tonal balance is progressively tilted by a HF enhancement since the V DOSC system is in essence more efficient at projecting HF energy than LF This is an important benefit of the V DOSC system With distance this tilt in tonal balance is
83. anar Symmetry of V DOSC Apart from coverage precision and predictability another significant benefit of V DOSC is the fact that the system effectively extends the near field region at higher frequencies For flat V DOSC arrays this results in a 3 dB reduction in SPL with doubling of distance as opposed to the 6 dB reduction that is typical of conventional systems This property arises due to the physics of cylindrical waves versus spherical waves see the figure below and Appendix 5 for further details Line source Point A 4A source V 4 R2 L ACOUSTICS V DOSC Hanual Version 3 2 10 01 Cylindrical Wave Expands in horizontal dimension only At 2R surface area increases 2 times 3 dB attenuation Spherical Wave Expands horizontally and vertically At 2R surface area increases 4 times 6 dB attenuation 13 119 This means that V DOSC should not be evaluated in terms of the classical kilowatt ratio i e due to it s ability to generate cylindrical wavefronts V DOSC has different attenuation properties than conventional systems Comparing SPL predictions according to standard calculations is not meaningful since V DOSC produces a combination of cylindrical and spherical wavefront propagation that must be evaluated using specific calculations Aside This is one of the reasons why modelling data is not available for V DOSC and other WST based systems manufactured by L ACOUSTICS EASE and CAT
84. arget I Verify the effects of equalization by repeating steps 8 10 2 Adjust the subwoofer level according to subjective taste 13 Finalize EQ adjustments focussing on the 25 300 Hz region 14 Predelay the entire system to the desired time reference For example if the drum monitor is the loudest element on stage use a system with time delay measurement capability to measure the time delay of the drum monitor with respect to the main system Otherwise base your system predelay on the geometrically determined delay L ACOUSTICS V DOSC Manual Version 3 2 10 01 89 119 15 Repeat the eq procedure for fill arrays L L downfill frontfill centre cluster 16 Time align fill arrays to the main L arrays by locating a measurement mic in the transition region where the coverage patterns overlap 7 Listen to a variety of familiar well recorded program material 18 Attenuate fill arrays relative to the main L system as required 9 Compare program as reproduced by the system versus a pair of high quality reference headphones monitoring the output of the mixing console Voice the system with a good quality vocal microphone 21 Verify tuning throughout the audience by walking the room and perform final adjustments using the analyzer between your ears c SIM MLSSA TDS SMAART SpectraFOO Measurements Equalization adjustments can be performed using an RTA analyzer with excellent results however more sophisticat
85. aveguide provides less than 4 mm of curvature For curved arrays enclosure tilt angles should vary in inverse proportion to the listener distance geometrically this is equivalent to shaping variable curvature arrays to provide equal spacing of individual element impact zones Limits exist given the vertical size of each enclosure and the relative tilt angles that are allowed between enclosures REFERENCES C Heil M Urban Sound Fields Radiated by Multiple Sound Source Arrays preprint 3269 presented at the 927 AES Convention Vienna March 24 27 1992 M Urban C Heil P Bauman Wavefront Sculpture Technology preprint not available prepared for the 111 AES Convention New York Sept 2001 L ACOUSTICS V DOSC Manual Version 3 2 10 01 112 119 APPENDIX 3 HOW DOES V DOSC BEHAVE WITH RESPECT TO WST CRITERIA The first Wavefront Sculpture Technology criterion STEP lt smallest A 2 over the frequency range of operation is fulfilled by a V DOSC array at low and mid frequencies With reference to Figure 51 The 15 speakers are separated by no more than 0 75 m and the crossover frequency is 200Hz corresponding to A 2 0 85 m The 7 speakers are separated by no more than 0 17 m and the crossover frequency is 300Hz corresponding to A 2 0 13 m max 0 75 m max 0 17 _ max 0 17 Figure 51 Front view of V DOSC array and vertically stacked DOSC waveguides We obviously ha
86. awk This plug and its outer housing are precisely constructed according to specific ratios between depth height and cone angle in order to produce the flat constant phase wavefront and tight manufacturing tolerances are obtained through the use of computer aided design and manufacturing CAD CAM techniques As shown in the AES preprint entitled Wavefront Sculpture Technology the deviation from a flat wavefront must be less than 5 4 at the highest operating frequency this corresponds to less than 5 mm of curvature at 16 kHz and experiments have shown that the DOSC waveguide provides less than 4 mm of curvature DOSC waveguide technology is patented on an international basis n 0331566 in Europe n 5163167 in North America L ACOUSTICS V DOSC Manual Version 3 2 10 01 114 119 APPENDIX 5 THE BORDER BETWEEN FRESNEL AND FRAUNHOFER REGIONS This appendix summarizes theory presented in Sound Fields Radiated by Multiple Sound Source Arrays AES preprint n 3269 presented at the 92nd AES convention in Vienna March 1992 Let s assume that the V DOSC array is flat and radiates a cylindrical wavefront The emerging wave will progressively expand to a spherical wave at a certain distance which depends on both the frequency and the height of the array V DOSC ARRAY A border FRESNEL FRAUNHOFER nearfield farfield CYLINDRICAL SPHERICAL Figure 54 Illustration of the Fresnel and Fraunhofer regions The bo
87. bbles we observe what is termed a chaotic wavefield If we throw a larger stone with total size and weight equivalent to the handful of pebbles then we see circular waves as was obtained with the single pebble except now with much larger amplitude If all of the individual pebbles of the handful could be glued together this would provide the same effect as the larger stone This illustrates the thinking behind V DOSC if we can build a single sound source from a number of individual speakers that can be separated for transport and handling then we have achieved our goal i e to provide a totally coherent predictable wavefield Therefore the initial specification at the beginning of the V DOSC research and development program was the design of a single acoustic source that was to be completely modular predictable and adjustable L ACOUSTICS V DOSC Manual Version 3 2 10 01 9 119 AAAA Figure I Wavefield interference for a conventional sound reinforcement system compared to a sculptured V DOSC wavefield b Wavefront Sculpture Principles As early as 1988 a preliminary system named Incremental had proven the feasibility of V DOSC From this experimental concept theoretical research was undertaken by Professor Marcel Urban and Dr Christian Heil The results of this research were presented during the 92nd AES convention in Vienna March 1992 preprint n 3269 The theory that was developed defines the acoustic coupling cond
88. cabinets adds 3 dB to the A weighted SPL anechoic or reflection free conditions direct sound only L ACOUSTICS V DOSC Manual Version 3 2 10 01 53 119 a Input Data Just as for the Cutview sheets user input data cells are in black and results are displayed in red To define a plan view of the audience area the user inputs x range and y distance off centre coordinates in the Contour and Contour 2 cells As coordinates are entered the display of the audience area is automatically updated and a mirror image drawing scheme is used so that only half the room needs to be defined It is only necessary to define Contour however Contour 2 is useful to represent balconies stage thrusts proscenium opening FOH location etc When V DOSC and dV DOSC arrays are defined in ARRAYI 2 and 1 2 Cutview sheets respectively they are automatically displayed in the H ISOCONTOUR sheet with the X Location of each array referenced to the defined Offset Distance taken from each arrays respective Cutview sheet The parameter Isocontour at Distance refers to the throw distance for the top element of the respective array and is given relative to the defined Offset Distance The user then enters the Console Output Signal dBu for each array i e output level of the mixing desk typically 0 VU on the console meter 4 dBu and the Continuous A weighted SPL is tabulated This corresponds to the SPL that would be obtained along the isoco
89. cators and amp clip indicators to verify system protection and gain structure L ACOUSTICS V DOSC Manual Version 3 2 10 01 35 119 Table 5 Approved Amplifier Input Sensitivities L ACOUSTICS LA 48 9 5 dBu 32 dB gain setting LAB GRUPPEN 4000 9 5 dBu 32 dB gain setting CROWN MA 5000VZ 9 2 dBu modified for 32 dB gain recommended 5 1 dBu 1 4 Vrms input sensitivity setting QSC POWERLITE 6 0 10 2 dBu 32 dB gain Once set it is possible to lock out limit thresholds for both BSS and XTA processors using the OWNER LOCK feature then storing the preset to another memory location 1 10 V DOSC PRESET SELECTION a V DOSC Preset Policy V DOSC presets are intended to be used as a reference for all Qualified V DOSC Technicians and Certified V DOSC Engineers According to L ACOUSTICS company policy key parameters are software protected and preset data is not freely communicated in order to preserve quality control confidentiality and to maintain the integrity of L ACOUSTICS system presets A lot of engineering and real world testing goes into determining optimum V DOSC presets detailed polar measurements and weighted spatial averaging are used to determine component equalization crossover points and crossover filter slopes for example As a result V DOSC presets give the user an optimum starting point system tuning should be done using band attenuation accurate subwoofer time alignment and system equalization not by altering
90. ce ring for a line array at observation point M If a circle of radius d is centered at M it intersects source i Recalling the condition that 2n 1 A 2 a second circle can be drawn with a radius of d 2 i e 0 in the expression for the path length difference If adjacent sources are inside the ring defined by 4 d A 2 then they do not cause cancellation they couple constructively If sources are outside the ring they may cause cancellation L ACOUSTICS V DOSC Manual Version 3 2 10 01 109 119 Decrease f Increase f Figure 47 The effect of varying frequency and listener position M on Fresnel rings As seen in Figure 47 when decreasing the frequency while maintaining the same listener position wavelengths get larger and the ring spacing gets bigger so that more sources fall within the ring and couple constructively at M Conversely as the frequency increases fewer sources fall within the ring and add constructively at M Maintaining the same frequency and therefore the same ring spacing and moving the position M closer to the array means that the radius of curvature of the rings is decreased therefore fewer sources fall within the ring Moving the listener position further away the radius of curvature increases and more sources fall within the constructive ring Now let s draw all circles with radii defined by 2n 1 A 2 The destructive areas where total cancellation occurs are shown in gray i
91. ck height adjustment blocks into the locating slots on the BUMPER and then lowering the screwjacks Note In some cases the front or rear pair of screwjacks can be omitted and the front or rear of the BUMPER laid directly on the stacking surface for added stability Aim the BUMPER in the correct direction to provide the desired amount of array rotation on or off stage Then raise the BUMPER at least 8 cm off the floor by rotating the screwjack wheels CW up CCW down This clearance is necessary so that screwjack wheels will not physically interfere with the dolley locator pins on the front of the bottom V DOSC enclosure Referring to the simulation results obtained using ARRAY the screwjacks are then adjusted to provide the required vertical angle for the lowest element NOTE A digital protractor or analog inclinometer is essential for performing angle measurements For stability reasons the maximum bumper tilt angle is 12 degrees It is important that the centre of gravity of the array remains within the footprint of the BUMPER i e with reference to the Gravity Abcissa value in the Mechanical Data cells of Array 2000 this value should be gt 0 42 mand lt 0 63 m The lowest element is then rolled up to the BUMPER while still on its dolley The dolley is unlocked then the element is lifted and placed on the BUMPER with the two rotating legs oriented upwards as a reference for cabinet orientation stacking runners on the cabinet
92. control is obtained down to as low as 80 Hz High SPL rejection outside of the defined coverage region also makes V DOSC an excellent solution in situations where environmental noise control is an issue for example in situations where outdoor amphitheatres are located close to residential areas The accuracy flexibility and predictability inherent in the V DOSC approach to sound reinforcement opens up many new horizons for sound design L ACOUSTICS V DOSC Manual Version 3 2 10 01 14 119 0 2 V DOSC TRAINING AND QUALIFICATIONS V DOSC is an innovative design which is based on a completely new approach to sound reinforcement It can provide fully predictable results to the extent that no other existing system is capable of However achieving the desired results requires following a rigorous procedure which may at first seem unusual to some sound designers and engineers Hopefully most of you will embrace this new technology and approach V DOSC with an open mind excited by the many new possibilities that such a system makes available However it can be hard to teach an old dog new tricks For those of you in this category the very first step to take is to forget your experience with other systems overcome your biases and forget all the tricks you have learned from past experience Try to accept the fact that THIS SYSTEM BEHAVES DIFFERENTLY V DOSC cannot be left in the hands of someone who has no experience with the system even if that
93. ct to the site angle of the top element which should be aimed at the rearmost part of the audience These cutview sheets are used to shape the vertical isocontour of either V DOSC or dV DOSC arrays to match the audience area Note Cutview sheets ARRAY and ARRAY2 are used to simulate V DOSC arrays while Cutview sheets dVARRAY and dVARRAY2 are used for dV DOSC In addition dVARRAY can be used to simulate dV DOSC used as downfill under V DOSC while dVARRAY2 can be used to simulate dV DOSC used as upfill longthrow on top of V DOSC The H ISOCONTOUR sheet displays the horizontal isocontour see Section 2 1 of all defined arrays projected onto a plan view of the audience area in the xy plane The SUB ARC sheet is used to calculate delay taps based on the physical configuration of a given subwoofer array for electronic arc processing see Section 3 4 g The ROOM DIM sheet can be used to help calculate xz cutview parameters based on room measurements The DATAcutview and DATAiso sheets are used for calculation purposes and should not be altered In general all input data should be entered into the cells in black Results are displayed in red L ACOUSTICS V DOSC Manual Version 3 2 10 01 48 119 CUTVIEW SHEETS ARRAYI ARRAY2 dV ARRAYI dV ARRAY2 a Input Data In AUDIENCE GEOMETRY cells the designer enters the distances and elevations that define the audience area according to a section view along the main zero degree axis of the sy
94. d 5 d IHOSOQ ra 297450212 8 3DN 31114 8 ISNA TIN v IH 2SOQ 9 Oll 280 QA 4 O12SOQ 975 8 12 95 8 32NvWTIC 8 32NvHTICH 9 IH 2SOQ x IW 280 QA OT12SO0Q 9 9158 1295 s Gua AE e HE H AH d 5 z 8 SONWH11N4 8 TIC x IH 2SOQ x 2609 9 012500 9 9158 1295 Fl 27450212 on f 00 amp DIHOSOQA NATIN a SONVETIN EN DNAT ___ 9 JONVHITI A _ i2soc WanssocA snsseras warn _ osoasa 8158066 _ SHO wols IHOSOCA 90125090 98581045 Ete IH dA IH O I OTSOWV 1 5 9 GIL SOTA O T SOA 90581295 We OI XU GA _ IHSSOGAP_ gojssogc __ eo1lcodg 985810445 acted IH AAP ACL GA IHSSOGAP_ 9orjssogc iH2soc WanmsocA o1lcodg 987581045 OIAFAG GA IHSSOGAP_ 8 015509 iH2soOgc osoasa 8058186 lt we IHXAGGA LUI HOSO TAP Q OTOSOQ AD GIL O T SOTA 49 91581295 We ans nun eiosoc osoasa snssra s ws IH AAA Wen nwa ei2soc WarnmsocA osoa ansaizas ws Wen Yna eio2soc
95. d completely fulfills the WST arrayability criteria defined above The key to the performance of the V DOSC element is the DOSC waveguide two devices are used in each enclosure to load two compression drivers All components of a V DOSC array are symmetrically arranged with respect to a plane vertically bisecting the array coplanar symmetry The enclosure contains 2X 15 loudspeakers connected separately 4X 7 midrange loudspeakers connected in series parallel and 2X 1 4 compression drivers connected in series which are mounted on 2X DOSC waveguides All components are weather resistant Although it is a 3 way design the enclosure is driven by 4 amplifier channels A V DOSC element is connected to the AMP RACK by V CABLE 7 m or 25 m length as required where the connector employed is an 8 pin Cannon CA COM of the bayonet locking type Each V DOSC element is provided with two connector sockets for direct connection and for paralleling of up to three enclosures elements are paralleled using V LINK DO 7 jumper cables The rectangular shape of the enclosure allows for easy stacking transport and handling A front mounted dolley board is provided for protection and transportation Stacking runners located on the bottom of the cabinet act as skid pads to protect the cabinet finish and mate with stacking runner recesses on the top of the enclosure for enhanced stability when stacking Cabinet dimensions were designed to allow for efficient
96. d up by approximately 8 dB or the low sub channels attenuated Since V DOSC and dV DOSC presets have been specifically engineered to provide an excellent starting point for system tuning it is always a good idea to set the desired ratios between high low and sub sections via simple attenuation and subjective listening before proceeding to perform detailed measurements and equalization Typically for 12 16 element V DOSC arrays the mid and high sections should both be increased by 3 6 dB to compensate for the enhanced low frequency coupling that occurs in larger arrays The frequency response for all presets is flat between 300 Hz and 4 kHz At higher frequencies the response is either flat or has a high frequency shelf of approximately 6 dB according to the selected preset i e smooth or bright LO or HI respectively Between 40 Hz and 160 Hz a low frequency contour of approximately IO dB is built into the preset Practically array coupling and room related effects will require equalization in the range of 160 Hz to 300 Hz Any other equalization will be the result of the engineer s subjective choice Due to the evenness of coverage afforded by dV DOSC and V DOSC equalization adjustments made at the mix position typically translate well throughout the audience Due to system coherence 2 dB changes on a graphic equalizer are dramatic When properly installed room related effects above 300 Hz are minimized and system performance translates
97. dles 1300 mm x 434 mm x 565 mm 51 27 x 17 1 x 22 2 108 kg 238 165 9 5 kg 21 Ibs for dolley L ACOUSTICS V DOSC Manual Version 3 2 10 01 96 119 Scale 1 20 Figure 40 V DOSC Element Line Drawing L ACOUSTICS V DOSC Manual Version 3 2 10 01 97 119 7 2 SB218 SUBWOOFER SPECIFICATIONS Frequency Response 28 Hz 140 Hz 3 dB Usable Bandwidth 25 Hz 200 Hz Sensitivity 2 83 V at Im 100 5 dB SPL 25 200 Hz freefield conditions Power rating 68 Vrms 1100 Wrms 4400 Wpeak long term pink noise with 6 dB crest factor Impedance 4 ohms Components 2 x 18 cone bass reflex 4 5 edgewound copper voice coil Material Baltic birch plywood Sealed screwed cabinet construction Finish Maroon gray Grill Black epoxy perforated steel with acoustically transparent foam Features Integrated flying hardware handles Dimension WxHxD 1300 mm x 550 mm x 700 mm 51 2 x 21 7 x 27 6 Weight 106 kg 233 165 9 5 kg 21 Ibs for dolley Scale 20 Figure 41 SB218 Subwoofer Line Drawing L ACOUSTICS V DOSC Manual Version 3 2 10 01 98 119 7 3 FLYING STRUCTURES a V DOSC Flying Bumper Dimension WxHxD 1262 mm x 140 mm x 1100 mm 49 5 8 x 5 4 8 x 43 3 8 Weight 61 5 kg 135 6 Ibs Scale 20 Figure 42 V DOSC Flying Bumper Line Drawing L ACOUSTICS V DOSC Manual Version 3 2 10 01 99 119 Table 12 Weights for flown V DOSC
98. e 28 ENDOSC AMPLIFIER RACK a a EEE 29 Wa FAN ELS sen an ee ee een 30 ES POWERING V DOS 33 129 V DOSC CONTROL za sn 34 a XTA DP224 DP226 Digital Signal Processors 34 b BSS FDS 355 FDS 366 Omnidrive Compact Digital Signal 34 c General Guidelines Regarding System Protection 1 2 6 2 0000 0000000000000000000000000000044 35 110 VEDOSG PRESET SELECTION en ee er 36 a V DOSG Preset Poly une een u 36 b General Description of V DOSC Presets 36 b BSS FDS 355 VERSION 6 0801 PRESETS FOR V DOSC 38 c BSS FDS 366 VERSION 6 0801 PRESETS FOR V DOSC 39 d XTA DP224 VERSION 6 0801 PRESETS FOR V DOSC 40 e XTA DP226 VERSION 6 0801 PRESETS FOR V DOSC 41 IH CONTROL OUTPUT PANEL uuu ayunanku u 42 KIZ MD24 MULETEDISTRO PANEL Sy 44 2 1 I
99. e array tends to flatten the aiming angles of individual enclosures SPACER blocks help to maintain the correct interelement angles The array is progressively raised and this procedure is repeated until all ANGLE straps and SPACER blocks have been connected to all elements Note that up to 8 dolley boards can be stacked according to the technique shown in Fig 36 u It is a good idea for someone to guide the array from behind as the system is flown the rotating legs on the bottom cabinet are useful as handles for this purpose Pay particular attention to steady the bottom element as it lifts off since it will want to flip forwards see Fig 36 v Before taking the system to trim float the array off the ground in order to tension the rear ratchet straps See Fig 36 w x Mounting a remote digital inclinometer on the top element and using a handheld digital inclinometer for the bottom element is the most accurate technique for matching the physical installation to what was simulated in ARRAY 2000 Essentially we want to adjust the ratchet straps so that the installed array has the correct Vertical Coverage Angle Cell P36 in ARRAY 2000 With reference to the remote inclinometer readout pretilt the array so that the top element is angled according to the Site 1 that was simulated in ARRAY 2000 Cell 124 Pretilting is important so that the ratchet straps will be tensioned while the array is in the final focus orientation since changes in c
100. e delay position to the stage 4 Focus the main LL L R and RR V DOSC arrays to a distance of 130 150 metres and locate delay positions at 100 120 metres with focus starting from 120 140 metres i e allow for 10 20 metre overlap between main array and delay system coverage 5 Time alignment of delays should be made on the axis of the reference source and the delayed source At a measurement point on this axis if the setting of the delay is such that the two sound waves arrive exactly at the same time the reference source will be ahead of the delay source at any other place off this axis Time domain based measurement equipment is essential for setting delay times see Section 5 2 regarding measurement procedures Alternatively Bushnell Yardage Pro rangefinder binoculars can provide a good starting point L ACOUSTICS V DOSC Manual Version 3 2 10 01 68 119 3 6 SAMPLE ARRAY CONFIGURATIONS Suggested array configurations are presented below for a variety of applications These examples are meant to provide a good starting point for detailed array design Installation parameters such as exact number of elements array height and element angling should be calculated using ARRAY on a case by case basis a Long amp Narrow Audience Format flat HORIZONTAL ISOCONTOUR 80 rated at 102 dB A weigted 70 or 114 dB SPL 60 50 40 Elts number dBV input 30 20 5 Headroom 5 5 9 9 o AUDIENCE CONTOUR 1 CONTOUR 2 2
101. ecessary do not reach for the graphic equalizer first Keep in mind that the best frequency response is not necessarily a flat line from 20 to 20k Hz see the above discussion on tonal balance 7 Duplicate settings for the other side and verify that both sides are the same 8 Measure the Left Right and Left Right response at the mix position and store the result 9 Measure the Left Right and Left Right response at several representative locations e g closer to the system equidistant between Left and Right arrays and within the defined coverage pattern and at the rear of the audience Store the results This is often difficult in open air situations since wind conditions can have an influence on the measurements A windscreen for your microphone can help make sure you are aware of the influence of this on the measured response 10 Compare all measurements to see if there is good correspondence i e system coverage is acceptable If there is good correspondence proceed to perform system equalization based on the average of all measurement locations If your analyzer allows you to apply different weighting give more weight to the console measurement double it in the averaging Use the parametric filters on the crossover inputs for performing system equalization Another useful eq approach invert the averaged measurement curve then use this as a target while electrically sweeping the equalizer and matching the eq curve to the t
102. ed by the height of the array up to 19m and broadens by 3 starting at 19 m For a person located less than 19m from the sound source frequencies below IkHz are radiated in spherical mode with an attenuation rate of 6 dB per doubling of distance All frequencies higher than IkHz propagate in cylindrical mode with an attenuation rate of 3 dB per doubling of distance 2000 He 52 2 112 43m 1000 Hz 2000 Hz 200 Hz L ACOUSTICS V DOSC Manual Version 3 2 10 01 116 119 Figure 55 Illustration of dborder and for a flat 12 element array APPENDIX 6 PATTERN CONTROL OF A CONSTANT CURVATURE ARRAY In practice the vertical coverage angle is controlled for frequencies greater than frequency F where 444 2 and N is the number of elements is angle between elements in degrees At F the vertical coverage angle is equal to the nominal value for the array i e N x A degrees At higher frequencies the coverage decreases to a value which is approximately equal to 2 3 of N x A This defines the minimum vertical coverage angle for the whole frequency range and is termed the beaming frequency F Vertical coverage angle then increases up to the nominal value at F defined by 4 77x10 2 AN For frequencies higher than F the vertical coverage angle is constant For instance a curved array comprised of 8 V DOSC elements with a constant curvature of A 4 pro
103. ed measurement tools such as TDS MLSSA SIM SMAART SpectraFOO for Macintosh allow the user to obtain better results provided these instruments are properly used of course Procedures using these measurement systems are identical to the techniques outlined above except for the fact that higher frequency and time domain resolution can be obtained along with time windowing capability to eliminate room reflections In addition impulse response domain measurements and the energy time curve ETC are excellent tools for time alignment of subwoofers and delay systems both in terms of accuracy and the actual time required for performing measurements and adjustments Signal averaging is generally very flexible and the ability to perform measurement weighting is possible with these measurement systems For fixed installations where system equalization is remotely located it is often useful to perform room measurements throughout a given array s coverage region then use a weighted spatial average to determine a house response curve The house curve is then inverted and used as an equalization target for adjusting the system equalizer which can be swept electronically using the analyzer and adjusted to meet the target curve Note if a fullrange crossover ouput is available this can be used to monitor the effects of input parametric filters very useful with Smaart use output 5 on the V DOSC X LO HI and 4W LO HI presets In general more sophisticated
104. em interference does in fact occur for the case of V DOSC however the main difference is that within the defined coverage region the interference is constructive while outside of the defined wavefield it is destructive see Appendix 2 For more details on how V DOSC satisfies WST criteria please refer to Appendix 3 For further information on the actual DOSC waveguide please see Appendix 4 V DOSC elements are vertically arrayed in two or four characteristic shaped columns Since elements of the array couple coherently the enclosures are physically smaller and fewer cabinets are required in comparison with conventional systems This makes V DOSC very cost effective for touring sound applications where transport space and handling time means money These properties also make V DOSC highly effective for fixed installation where compact size combined with predictable coverage is important One of the key benefits of WST is the predictability of the wavefront s shape Horizontally the entire V DOSC array has the same coverage angle as a single element 90 Vertically the coverage is directly determined by the number of arrayed elements and the specified angle of separation between them Given this predictability vertical coverage can be optimized to match specific audience area requirements A quick user friendly CAD spreadsheet helps the operator to determine how to focus the wavefield so that tonal balance and sound pressure levels are even
105. entre of gravity for the array due to changes in Site Angle 1 will affect interelement angles Using a handheld inclinometer on the bottom element tension the ratchet straps so that the bottom element site angle is equal to the Site Angle N in ARRAY 2000 where N the number of elements This procedure gives you exactly the Vertical Coverage angle for the array that was simulated in ARRAY 2000 When the system is taken to trim Site Angle 1 will have to be readjusted using the remote inclinometer readout or with reference to the laser see below since chain motors do not run at exactly the same speed Note DO NOT OVERTIGHTEN THE RATCHET STRAPS especially if the array is tilted upwards The goal is to simply take the slack out of the ANGLE straps Overtightening the ratchet straps can increase the angle between enclosures up to additional degree per cabinet the gap at the rear of the enclosures closes similar to a stacked system b Trim and Angle Adjustments At this point there are only two adjustments left i e the trim height of the array and the tilt angle of the first element The rear motor is used to set the proper height of the whole array Controlling the tilt angle is performed by the relative action of both two chain motors i e once the proper height has been set activating the front motor upwards or downwards varies the tilt angle NOTE Always fly the array without tilt initially Applying tilt before the ar
106. eral pieces of string or light rope can be run from the floor over the BUMPER and to the Maglite laser device or remote inclinometer in order to pull the instrument free and lower it after measurements have been performed As a final check mute mid and low channels and run pink noise through the system and listen to the high section coverage throughout the venue to verify that installation is correct If a DELTA PLATE is used on or off stage rotation of the entire array can also be adjusted Three motors are used in this case and a rotating shackle connects the DELTA PLATE to the BUMPER Together the two rear motors control the height of the array and the relative action between them controls the rotation As before the front motor controls the tilt angle Use the above described techniques to verify that L and R arrays are matched plus L L and R R arrays if installed Important things to note concerning the use of ratchet straps Tightly ratcheting flown arrays is not recommended for the following reasons Ratcheting increases the angle between flown enclosures up to an additional degree i e a 4 degree ANGLE strap can produce 5 degrees etc This increase in angle be non constant vertically along the array and is difficult to predict control typically the bottom elements are affected first 5 5 degree ANGLE strap can be modified to a 6 5 degree value with tight ratcheting and WST criteria will not be satisf
107. f avoiding potential phase shift problems due to overlapping crossover points and can work in virtually any situation provided that the results are subjectively acceptable V DOSC 3W 3WX presets provide another alternative for use with aux sub drive that helps to maximize the amount of low end coming from the V DOSC system itself with an additional margin of highpass filter protection for the low section i e 50 45 Hz HP filtering for 3W 3WX respectively versus 27 Hz for X The 3W and 3WX presets also take advantage of L R stereo linking The important thing to remember is how FOH engineers work with aux sub drive throw up the kick on the main system make it sound good then bring it up on the aux send It has to sum properly when the aux send is blended in so once subs are time aligned with respect to the main arrays the overall low end contour should be checked with differing aux send levels nominal 5 10 etc to make sure things respond linearly WARNING Always check the polarity of the subwoofer section to optimize low frequency performance J E Stage Stage Figure 26 The 218 as an effect The subwoofer array and V DOSC array are physically separated gt 6 m Dedicated presets have the 4W suffix and 80 Hz low pass filtering is employed for subwoofers Alternatively the X preset can be used with input B output 6 XTA 226 or BSS 366 or input B output 5 BSS 355 or stereo 3W 3WX presets can be employed with
108. fication procedures are described in Section 4 2 BAD II 2999 r3 at 4 E GOOD gt vertical N b ww Figure 23 Illustration of Flying Guidelines L ACOUSTICS V DOSC Manual Version 3 2 10 01 58 119 3 3 THE LEFT RIGHT CONFIGURATION a The Standard Configuration Although not the best technical solution the left right configuration meets both visual and practical criteria and is most commonly used V DOSC is a dramatic improvement over conventional systems but by nature the stereo imaging of a standard left right system is questionable for most of the audience and some compromise with respect to overall tonal balance has to be accepted The biggest problem for any left right system is non uniformity of tonal balance over the audience Typically an excess of low frequency energy builds up in the middle along a narrow path from the stage to the back of the venue This is often accompanied by a reduction of intelligibility over the same area The net result is a thick sound response in the middle aggressive when directly on axis with one side of the system and thin offstage These effects are due to the path length difference interference effects inherent in any left right system which in turn produce frequency and position dependent peaks and dips Figures 24 a b and c show techniques for optimizing low frequency tonal balance over the audience with a left right configurat
109. further back in the audience this is a highly desirable property that also results in reduced potential for hearing loss for both audiences and engineers alike Nearfield extension combined with the precision and predictability of V DOSC coverage is also effective in pushing back the critical distance in highly reverberant spaces critical distance is defined as the distance where the energy of the direct sound is equal to the reverberant energy In many situations it is extremely important to keep energy off the roof for example in outdoor sheds amphitheatres and arenas If we can excite less of the reverberant energy in the room and focus more energy on the audience we can effectively move back the critical distance in a given room Given the well defined vertical coverage of V DOSC the benefits of WST become immediately obvious in comparison with conventional systems when working in difficult rooms Finally another benefit of WST is the high degree of SPL rejection that is obtained outside of the defined wavefield Nominally as high as 20 dB this permits the installation of a V DOSC array behind or above microphones with exceptionally high feedback immunity Monitor engineers also enjoy working with V DOSC FOH systems since there is very little backwave on stage even at lower frequencies due to the coplanar symmetric arrangement and vertical line array configuration of the low section for larger arrays of up to 16 elements pattern
110. g structure is made of a rectangular steel main frame with heavy duty cross bracing Rigging accessories required for flying and stacking V DOSC include 8 shackles 4 steel slings 2 pear rings 4 screwjacks 2 ratchet straps plus ANGLE straps and SPACER blocks The two rotating legs Balanciers along with U shaped locking pins Axfixe located on the bumper are used to hang the first V DOSC element of the array There are also two vertically oriented Aeroquip flytrack E rails allowing for attachment of the first element to the BUMPER using the BUMP angle strap When flown the BUMPER is hung from two points spaced by 1 05 m 43 4 one front and one rear The center of gravity of the whole array is exactly vertical from the line joining these two points Motors can be attached to the central hole locations on the bumper or alternatively for additional safety factor when flying large arrays the two outer hole locations front and rear can be used for bridling using 4 steel slings 2 front 2 rear 8 shackles and 2 pear rings A unique feature of the V DOSC flying system is the fact that the relative action of the front and rear chain motors can adjust the vertical angle of the entire array since the array is connected rigidly to the BUMPER Although ANGLE straps determine the angle between adjacent V DOSC elements the rear rotating legs of the caterpillar type assembly provide the mechanical connection and bear the majority of the load As
111. ging conditions apply with respect to load distribution see below for further details The designer then chooses the angular spacing between elements from the available values 0 75 3 2 3 4 5 5 The red lines show the aiming directions of all elements where each line is aligned with the bottom of its respective enclosure Note that the displayed top element corresponds to the BUMPER not the first element of the V DOSC array XZ cells can be used to enter additional room features such as balcony profiles stage proscenium details FOH mix position etc b Optimization Procedure The calculated beam display indicates the effective vertical coverage of the array above F where F is defined as the low frequency limit of the clarity domain i e above F WST criteria are fully satisfied and cylindrical wave propagation applies see Appendix 6 for further details Intersection of beams with the audience square blocks impact zones represents the dispersion of sound pressure level over the audience The best results are achieved when the audience intersection points have equal spacing between them In this case the SPL decreases by 3 dB when doubling the distance see Figure 19 for details L ACOUSTICS V DOSC Manual Version 3 2 10 01 50 119 NON CONSTANT SPACING CONSTANT SPACING 4 Ar 2xA 6 dB attenuation per 3 dB attenuation per distance doubling distance doubling Figure 19 Optimizing Array Elemen
112. gs for a condensed point source line array at observation BOME M sun een ae 112 Figure 50 Destructive interference rings out of beamwidth for two kinds of line arrays condensed EE 113 Figure 51 Front view of V DOSC array and vertically stacked DOSC waveguides 114 Figure 52 Horn Generated acc aaa M vd V mad IR I UM Gees 15 Figure 53 DOSC Waveguide Internal 15 Figure 54 Illustration of the Fresnel and Fraunhofer regions 116 Figure 55 Illustration of dborder and Dv for a flat 12 element 118 Figure 56 Illustration of the variation of vertical coverage angle with frequency 118 LIST OF TABLES Table T FADOS Wiring Chart en ana ee a 3 Table 2 PAD02 Wiring Chapuna u u nee LEER 32 Table 3 Load and Power Ratings for V DOSC 33 Table 4 Recommended Power and Amplifier Power Ratings EIA IkHz 1 THD 33 Table 5 Approved Amplifier Input Sensitivities 36 Table BSS FDS
113. h pass filtered at 80 Hz Complimentary low high pass filtering helps to avoid phase problems due to overlapping sub and low operating bandwidths so that subs can be operated in positive polarity Excellent results can be obtained using the 4W preset however this solution is not recommended for high SPL applications since less low frequency energy is radiated by V DOSC due to the 80 Hz high pass filter Alternatively the X preset can be used with aux sub signal applied to input B and the sub drive signal taken from output 6 XTA DP226 or BSS 366 processors or output 5 BSS 355 When the X preset is used in this way the V DOSC low section is high pass filtered at 27 Hz and subs operate from 27 80 Hz with negative polarity note this corresponds to the previously named SB preset NOTE Subwoofers are usually installed on the floor next to each other to take advantage of the enhancement obtained due to floor coupling However this gain may be partly lost when the signal is shared with the flown V DOSC array due to path length differences and phase shift It is well known that time alignment is only valid in one direction and that phase shift is frequency dependent The most critical case occurs at the low pass frequency for the subwoofers 80 Hz since a 24 dB per octave crossover filter generates a phase shift of 180 At equal distance from the two sound sources this phase shift causes cancellation when both the flown array and ground stacked
114. he mix position the rear of the audience equidistant between the Left and Right Arrays Mute the highs and mids Individually feed the low channel of the main arrays then the subwoofers with pink noise and adjust the crossover output levels to obtain the same measured level Invert the sub polarity Feed subs and lows with pink noise and fine tune the delay adjustment by up to 5 msec from the geometric delay to obtain maximum cancellation If varying the subwoofer time delay has no effect then change the crossover preset and adjust the delay to provide maximum cancellation the polarity of the subs and confirm that maximum summation is obtained If a time domain measurement system is available a good trick to get better time resolution for subwoofer arrival time measurements is to increase the lowpass filter from 80 or 200 Hz to 5 kHz don t forget to put it back when you re finished 6 Check the overall tonal balance of one side select the correct preset and perform basic band attenuation using crossover output level adjustments sub low mid high ratios to achieve the desired tonal balance Record the result and store it in an available memory location Note For larger arrays 12 16 elements due to increased coupling of the low section mid and high section outputs should both be increased by 3 6 dB in order to achieve correct spectral balance Simple attenuation is generally all that is n
115. heir respective subwoofer arrays It is recommended that arc radii remain shallow so that the difference between T3 and T4 remains less than 5 msec Steeper arc radii will decorrelate L L and L V DOSC arrays to the extent that the L L array will be perceived as an echo with respect to the L array Apart from smoother low frequency coverage electronic arc processing of the main arrays has the added benefit of improved stereo perception since psychoacoustically such processing helps to localize the audience s attention towards the stage not the nearest speaker array Since they are used as an extension of the flown V DOSC systems subwoofer arrays for L L L R and R R can be low pass filtered at 200 Hz X preset while all central subwoofers are low pass filtered at 80 Hz Experiments are ongoing at L ACOUSTICS to determine optimum arc radii and subwoofer array configurations for various applications h Other Techniques for Reducing Centre Buildup Apart from electronic arc processing of a single centre line of subwoofers two other techniques are illustrated below For the case of L R arrays that are wrapped around stage corners the idea is that by directing energy of the individual L R sub arrays offstage reductions of the centre buildup are obtained For the case of the LCR sub array L R arrays are oriented at 45 degrees offstage for the same reason and instead of a single buildup between L R arrays as for L R split stacks with an LCR array
116. herent chaotic X wawveftield x wavefield de x illustrating x lt rejection out of beamwidth Figure 50 Destructive interference rings out of beamwidth for two kinds of line arrays condensed and standard The ideal situation is achieved when sound sources get so close to each other that they become equivalent to a flat ribbon a continuous linear source This solves the source separation problem at higher frequencies where the wavelength is smaller than the size of the drivers for example 2 cm at f 16 kHz since the chaotic multiple source wavefield is replaced by a single well defined wavefront With further analysis we show in the first AES preprint that optimized coupling can be achieved in two ways the first way is to minimize the spacing of sound source acoustic centers to less than half the smallest wavelength corresponding to the upper frequency of their operating bandwidth the second way is to shape the radiated wavefront of the sound sources into a flat isophasic ribbon with no more than 20 discontinuity of the radiating area In the second AES preprint entitled Wavefront Sculpture Technology these two WST Criteria were re derived based on an intuitive approach using Fresnel analysis and in addition it was shown that The deviation from flat wavefront must be less than 4 at the highest operating frequency this corresponds to less than 5 mm curvature at 16 kHz and the DOSC w
117. ied When ratchet straps overtightened and the array is excessively tilted upwards physical damage can result to the flytrack and or ANGLE strap fittings see above L ACOUSTICS has developed a SPACER block to eliminate the need for use of ratchet straps specifically for the case of arrays with upwards tilt L ACOUSTICS V DOSC Manual Version 3 2 10 01 79 119 Moderately ratcheting flown arrays IS recommended for the following reasons Ratchet straps introduce a continuously variable tweak factor that allows for fine tuning of coverage down front and greater ANGLE strap resolution when used correctly When the array is pointing downwards the centre of gravity shifts backwards and the top V DOSC elements tend to close naturally forming a flat long throw section this is desirable for flat audience open air festival situations For larger 12 16 element arrays even though 0 75degree ANGLE straps are used for the first 6 8 elements the actual obtained angles will be close to zero with no ratchet when the system is flown and the top element focussed downwards Moderate ratcheting then introduces the possibility of continuously variable angles between 0 to 0 75 degrees and the progression is monotonic as a function of height For example if a 16 element array is pointing 4 degrees down and 0 75 degree straps are used for the first 8 elements combined with moderate ratcheting actual values on the order of 0 0 0 25 0 25 0
118. iers with 32 dB gain as standard The L ACOUSTICS RKI2U rack contains 4 L ACOUSTICS LA 48 amplifiers and can power 1 1 2 2 3 3 V DOSC 4 4 SB218 subwoofers 6 6 dV DOSC or 6 6 ARCS When powering V DOSC 2 enclosures in parallel is the optimum load while 3 is more cost effective Powering 3 3 V DOSC elements is safe for the amplifiers but does not provide the same standard of sonic quality due to reduced headroom Powering 4 4 elements from a single amplifier rack is not recommended for normal operation but it is possible to do so in emergency situations When powering V DOSC 2 amplifier channels power the LF section since the 15 components are cabled separately one channel powers the MF and one channel powers the HF If we consider the four amplifiers in RKI2U as numbered 4 from top to bottom nominal impedance loads and amplifier channel assignments when powering a single V DOSC cabinet are 6 ohms on high frequency channel Amplifier 1 Channel A 1 8 ohms on mid frequency channel Amplifier 2 Channel A 2x8 ohms on both low frequency channels Amplifiers 3 4 Channel A When powering subwoofers each amplifier channel is assigned to one SB218 providing a 4 ohm load Multiple cabinet impedance loads and power ratings are summarized in Table 3 Recommended amplifier power output ratings are given in Table 4 Table 3 Load and Power Ratings for V DOSC ONE THREE V DOSC V DOSC SECTION LOAD PEAK RE
119. ing the two arrays becomes too great A standard distance of 20 m 65 ft is acceptable however if greater separation is specified one should avoid rotating the arrays onstage too much this emphasizes arrival time differences between the arrays thus degrading intelligibilty The decision as to whether to emphasize intelligibility or stereo imaging mainly depends on the application New age music obviously does not require the same type of configuration as speech reinforcement ZI o lih a FO 110 120 130 140 1 CN 1 110 120 130 140 130 Figure 25b Optimizing stereo imaging L ACOUSTICS V DOSC Manual Version 3 2 10 01 61 119 3 4 SUBWOOFERS Subwoofers are primarily used to extend the frequency response of the V DOSC system down to 30 Hz and to increase the overall SPL without increasing the potential for audience hearing loss a General Guidelines for the Use of Subwoofers The number of subwoofers to be used depends on 3 parameters Number of V DOSC Elements the standard number of subwoofers recommended is 5 V DOSC SB218 for example 3 2 6 4 9 6 12 8 15 10 Type of Program Material the standard subwoofer number is recommended for rock and pop music For intense heavy metal house music rap or techno 1 1 ratio is desirable for classical music or corporate events 2 1 is acceptable Type of Venue or Installation In open air when subs are ground stacked the quant
120. ing use note for ventilation purposes front and rear doors must always be removed during operation A high impact resistance polyethylene cover provides protection for the rack during transport so that no external case is required Four recessed Aeroquip flytrack sections are mounted on both sides of the amplifier rack for flown applications L ACOUSTICS V DOSC Manual Version 3 2 10 01 29 119 There are recesses in the top cover of each rack that allow racks to be stacked on top of each other with the castors still attached It is also possible to remove the casters on one amplifier rack place it on top of a second amp rack and then mechanically bolt the two racks together Overall the L ACOUSTICS amplifier rack provides an extremely efficient package in terms of power versus size and weight while at the same time maintaining flexibility for smaller scale and distributed system applications Please see the LA 48 specification sheet and user manual for a full description of features 1 7 V DOSC AMP PANELS C V DOSC AMP PANEL L ACOUSTICS 09 S oe PITIIIIS SEER IIIIIS D SIGNAL SIGNAL C INPUT OUTPUT Cj PADO2 2 amplifiers per rack z V DOSC AMP PANEL L ACOUSTICS Wee CHA o sss 3 o VAA 9 90 ose SS SS 2 S Beer CHB 2 SIGNAL SIGNAL C SPEAKERS CH A INPUT OUTPUT SPEAKERS CH B PAD04
121. ingle array as well as an estimate of the peak unweighted SPL for 2 arrays is also given Note that these unweighted SPL estimates do not include additional contributions due to subwoofers Vertical coverage of the array is calculated as the addition of intercabinet angles As discussed above this coverage becomes effective at F defined as the lowest frequency of the clarity domain For all frequencies higher than F the vertical coverage angle is controlled within the nominal vertical coverage angle Above F the vertical coverage angle perfectly matches the nominal value Some beaming vertical coverage narrowing may occur at F especially when the array is of constant curvature type Further theoretical details related to the calculation of F F and are given in Appendix 6 Finally MECHANICAL DATA gives an estimate as to the rear versus front motor and balancier versus BUMP angle strap load distribution These load distributions depend on the size and shape of the array as well as the array site angle equal to Site 1 which in turn affect the location of the centre of gravity Important things to note I ARRAY WEIGHT includes V DOSC enclosures the V DOSC BUMPER and angle strap weights only Loudspeaker cable weights steels and motor weights are not included 2 Calculation of the REAR LOAD is within 2096 error When the rear motor load goes to zero Maximum Site Angle is displayed 3 Calculation of the FRONT LOAD is within
122. ion 2 by focussing the arrays at different panning angles comb filtering interaction is lessened since their overlap region is reduced In addition the ear cannot resolve tightly spaced comb filtering notches at higher frequencies throughout the overlap region The array closest to the stage is usually the larger of the two arrays This array is considered as the time reference and any other array is delayed with respect to it This is valid for arrays fed with the same signal in a stereo configuration it is obvious that the left array is not delayed with respect to the right one or vice versa Experience has shown that this is a very flexible approach that can cover any type of audience An additional advantage of multiple arrays is improved resistance to wind effects in open air situations Another benefit is improved perception of stereo effects throughout the audience area something which should not be limited to just the mix position i e arrays can be run in cross panned stereo with L L right L left R right and R R left Beyond the basic solution of coverage problems multiple source arrays open up many possibilities for creating a spatial soundscape thus providing a powerful tool for sound design and creativity A number of suggested configurations suitable for use in a wide variety of situations are given below in Section 3 6 These suggested configurations should serve as a useful starting point for detailed sound design
123. ion In Figure 24 a the subwoofers are arranged in a vertical column and physically separated from the V DOSC array DSP presets to be used for this case have the 4W extension In Figure 24 b a center line array of subwoofers is used to augment or replace left and right vertical line arrays Electronic arc processing can significantly improve low end coverage for a single horizontal line array configuration especially for large scale systems when Left Left and Right Right arrays are added In Figure 24 c the subwoofers are flown directly beside the V DOSC arrays This configuration is a good solution to avoid the local excess of low frequency directly in front of subwoofers DSP presets to be used for this configuration have the X extension although 4W presets can also be used Typically adding several ground stacked subs per side supplies sufficient low end impact for the closest audience members Figure 24 d shows a non recommended configuration since the horizontal subwoofer arrays split L R stacks emphasize the center lobe by increasing the directivity This is only desirable for long and narrow audience configurations Please note that a detailed discussion of techniques for integrating subwoofers with V DOSC follows in Section 3 4 a L ACOUSTICS V DOSC Manual Version 3 2 10 01 59 119 11 12 oe Ze E ES ott Se pp RE
124. ions 2 through 1 7 Please note that specific multiconductor connector selection for system drive remains open for the user to define although L ACOUSTICS does recommend a specific connector type that is supplied with turnkey systems L ACOUSTICS recognizes the fact that multiconductor snakes and connectors represent a significant investment and many users already have their own internal standard that they must adhere to Therefore this part of the Universal Standard remains flexible Specific multiconductor connectors can be accomodated on special request the only components that need to be customized are the CONTROL RACK OUTPUT panel and the MULTI DISTRO panel Other elements that must remain standard in order to ensure compatibility include multiconductor line assignments crossover channel assignments and presets amplifier rack connectors for speaker connection amplifier rack connectors and channel assignments for signal distribution In addition L ACOUSTICS specifies only approved amplifiers and digital processors for use with V DOSC NOTE Some V DOSC systems available on the market do not comply with the Universal Standard and are considered non approved by L ACOUSTICS For the case of custom non standard systems L ACOUSTICS does not accept responsibility for misuse or misoperation and in some cases the warranty may be considered void L ACOUSTICS encourages all users to comply with the recommended standard as closely as possible in o
125. it is planned to hang 16 loudspeakers to the bumper The maximum load to hang is therefore 1 790 daN to which the weight of the tackles and links must be added 3 DESCRIPTION OF THE HANGING SYSTEM refer to sketch 14 in annex The bumper hanging frame is hanged by shackles links and 2 tackles to the load bearing structure of a building Under the bumper a set of loudspeakers maximum 16 is hanged There are connected at the back by U axes Laterally AVIA rails fixed to loudspeakers are inter connected by adjustable links The purpose of this system 1s to ensure an angular orientation between the loudspeakers for the sound diffusion Therefore only the system by U axes is provided to bear the weight of the loudspeakers Sketches 1 to 20 correspond to various parts of the hanging system 4 HOIST INSTRUCTIONS The hoist intervention is described in annex paragraph 3 3 Installation of a suspended 4 sheets Make sure before implementing the hoist that the anchorage points on the building have the capacity of bearing the loading planned refer to the load assumptions L ACOUSTICS V DOSC Manual Version 3 2 10 01 118 119 Affair Heil Acoustics V DOSC System Hanging system of loudspeakers CR51B950374C 5 ASSESSMENT ON THE HANGING SYSTEM a Technical dossier forwarded folios 1 to 20 assembly instructions attached Documents provided are satisfying as for the stability in reference to standards and rules of chapter II Refer
126. itions required for effectively arraying individual sound sources Relevant parameters include wavelength the shape of each source the surface area of each source and the relative source separation In brief the WST coupling conditions can be summarized as follows An assembly of individual sound sources arrayed with regular separation between the sources on a plane or curved continuous surface is equivalent to a single sound source having the same dimensions as the total assembly if one of the two following conditions is fulfilled 1 Shape The wavefronts generated by the individual sources are planar and the combined surface area of the sources fills at least 80 of the target surface area 2 Frequency The step or source separation defined as the distance between the acoustic centers of the individual sources is smaller than half the wavelength at all frequencies over the bandwidth of operation These two criteria form the basis of Wavefront Sculpture Technology referred to as WST throughout this text For further information more detailed theory is presented in Appendix 3 Additional WST Criteria were developed for the AES preprint entitled Wavefront Sculpture Technology that was prepared for the 11 Convention NYC Sept 2001 preprint not available The first two WST Criteria were re derived based on an intuitive approach using Fresnel analysis and in addition it was shown that 3 The deviation from a flat wavefront must
127. ity remains standard When flown additional subwoofers are required Indoors at least one subwoofer is required per 7 500 m volume b Combining V DOSC With Subwoofers In this section we present techniques for optimizing the coupling between a V DOSC array and subwoofers Two cases are considered depending on the intended purpose of the subwoofers i e in some applications subwoofers are used as an effect and are not driven with the same signal as the main system separate auxiliary send from the console while in other cases the subwoofers are used as a low frequency extension of the array and are driven with the same signal in 4 way mode A V DOSC array is capable of radiating frequencies down to 40 Hz at high level with good vertical pattern control due to the length of the array Taking advantage of this capability a V DOSC array is usually not high pass filtered higher than 27 Hz When adding subwoofers to the system part of the frequency range can overlap depending on the selected preset resulting in the potential for interference Techniques for controlling this interference and maximizing the combined response of low and sub channels are discussed below for the two different cases c The Subwoofer as an Effect In this case subwoofers are driven from a separate aux send off the console and there are several preset options For the 4W preset the subwoofer signal is low pass filtered at 80 Hz and the V DOSC low section is hig
128. kHz 0 1 THD nominal POWER 1300 W 8 ohms 2100 W 4 ohms 2400 W 2 ohms b CROWN MA 5000VZ The CROWN MA 5000VZ amplifier is nominally set at 1 4 Vrms input sensitivity This setting is equivalent to 2 9 dBV or 5 ldBu input sensitivity and provides a constant gain of 37 dB However in order to remain compatible with the 32 dB gain specified for the V DOSC standard a PIP card is required Please refer to the CROWN MA 5000VZ manual for a complete description of LED readouts different combinations of ODEP Signal IOC and l Load I Limit indications have different meanings A brief summary of important specifications follows INPUT SENSITIVITY 1 4Vrms 5 14 dBu GAIN 32 dB gain specified setting for V DOSC requires PIP card Maximum at kHz 0 1 THD POWER 300 W 8 ohms 1850 W 4 ohms 2400 W 2 ohms c Lab Gruppen 4000 For a detailed description of the 4000 please refer to the LAB GRUPPEN Users Manual A brief summary of important specifications follows INPUT SENSITIVITY 2 30 Vrms 9 5 dBu GAIN 32 dB gain specified setting for V DOSC available on request FIA kHz 1 THD POWER 1300 W 8 ohms 2100 W 4 ohms 2400 W 2 ohms L ACOUSTICS V DOSC Manual Version 3 2 10 01 106 119 APPENDIX WHY DO SEPARATED SOUND SOURCES INTERFERE When two sources are physically separated such as two speakers or two horns in an array the slightly different arrival times of the wavefronts radiated by the i
129. lown all ANGLE strap labels will be visible from the rear this is useful and makes for a cleaner installation see Fig 36 i Connect all elements to the AMP RACKS using V CABLEs and V LINK jumpers between elements for parallel operation NOTE it is best to connect cables from the AMP RACKS to the cabinets first and jumpers last in order to avoid cable reversal Longer cables can be routed over the BUMPER or secured using a spanset then velcro straps or tape used to secure cables to the U pins for strain relief see Fig 36 Route two ratchet straps through the U pins of the bottom enclosure and over the bumper Orient the ratchet strap so that the ratchet handle is accessible from the top outside once flown see Figs 36 m n Note as an alternative to ratchet straps SPACER blocks can be employed see Figs 36 i iv As a general rule ratchet straps are acceptable when the system is pointing downwards spacer blocks should be used when the system is pointing upwards Remove all dolley pins As the array is flown the cabinets will automatically lift off the dollies see Fig 36 o q Conduct a final inspection to make sure all cabling is correct correct ANGLE straps are in place and securely seated in the flytrack all U pins are fully inserted and all U pin safeties are locked in place Attach the rear chain motor to the rear BUMPER fly point using a shackle See Fig 36 p Do not connect the front chain motor yet this can be d
130. ls total The 84 pin MASS W6 connector accomodates these 24 drive channels 72 lines leaving 14 lines available for amplifier remote control It is important to have discrete drive for all four arrays for several reasons a discrete drive allows for the relative time alignment of all 4 arrays i e typically the L array will act as a time reference for the L L array while the R array acts as a time reference for the R R b different sized arrays will require different band attenuation and equalization i e typically the L L and R R arrays used for offstage coverage are smaller in terms of the number of elements c discrete drive for all four arrays allows for the creation of stereo over larger audience areas i e using the console s matrix outputs the stereo left signal can be applied to the L and R R arrays while stereo right can be sent to the R and L L arrays L ACOUSTICS V DOSC Manual Version 3 2 10 01 42 119 1 12 MD24 MULTI DISTRO PANEL L ACOUSTICS MD 24 MULTI DISTRO LEFT LEFT LEFT RIGHT RIGHT RIGHT A CEN CEN 3 3 OUT m 92226 NA NA NEA _ A B D Figure 13 V DOSC MD24 MULTI DISTRO Panel As seen in the system block diagram of Figure 4 a MULTI DISTRO panel is required onstage for distribution of MULTI return snake lines from the FOH A single MULTI DISTRO panel is required typically the MULTI DISTRO panel can be packaged separately and located either stage left or stage
131. ly distributed throughout the listening area Using this program array design can be conveniently performed on a case by case basis to optimize coverage for each venue according to the specific audience layout The configuration of transducers in a V DOSC element is symmetrical with respect to the plane of propagation of the wave i e the plane bisecting the horizontal coverage angle High frequency transducers are located in the middle mid frequency transducers are on both sides of the high section and low frequency transducers are laterally positioned on both ends Such a configuration is described as having COPLANAR SYMMETRY Coplanar symmetry is the cylindrical domain equivalent of the coaxial arrangement for individual spherical sources Essentially coplanar symmetry allows for homogeneous coverage of the sound field at any listening angle over the V DOSC array s 90 horizontal coverage window Coplanar symmetry also eliminates off axis acoustic cancellations at crossover frequencies so that polar lobing is not an issue Psychoacoustically coplanar symmetry is largely responsible for the exceptional stereo imaging properties that are characteristic of V DOSC The DOSC waveguide is registered under European patent n 0331566 and North American patent n 5 163167 Please see Appendix 4 for a description of the DOSC waveguide L ACOUSTICS V DOSC Manual Version 3 2 10 01 12 119 Figure 3 Copl
132. m dB AUDIENCE CONTOUR meters CONTOUR 1 CONTOUR 2 x 70 40 50 60 80 90 100 110 HORIZONTAL ISOCONTOUR SHEET Figure 21 ARRAY spreadsheet calculation example L ACOUSTICS V DOSC Manual Version 3 2 10 01 55 119 3 ELEMENTS OF SOUND DESIGN 3 1 MULTIPLE ARRAY CONCEPTS a Reducing Array Interaction It is well known that the collective radiation of sound by a number of loudspeakers located close to each other results in interference that creates frequency and position dependent interference lobes The only coherent way to couple loudspeakers is to meet Wavefront Sculpture Technology criteria which for the case of V DOSC is met in the vertical domain When the horizontal coverage of a V DOSC array 90 nominal 70 effective is not sufficient the solution is definitely not to place a second array directly beside the first one see Appendix for further elaboration The correct approach is to utilize a second array which is focused on another portion of the audience typically at 45 70 relative to the first array and spaced at least 6 7 meters approximately 20 ft away from the first array Given this separation interference only occurs in the low frequency range and there are no audible intelligibility losses for two reasons the first main cancellation is shifted lower in frequency example 24 Hz for 2 arrays of the same size spaced 7 metres and tends to be masked or filled in by room reverberat
133. n oom IL A FNIT k Y i eal M oy i ak Em w CIEC AP OSOQ A Zl SA vv WELLSAS Figure 4b Example System Configuration 18 119 10 01 L ACOUSTICS V DOSC Manual Version 3 2 c V DOSC System Components V DOSC Full range 3 way loudspeaker enclosure meeting WAVEFRONT SCULPTURE TECHNOLOGY criteria with coplanar symmetric arrangement of drivers 2 SB218 Complementary subwoofer for high level extended bandwidth applications 3 CONTROL RACK Control rack for system drive containing digital processors with custom engineered system presets CO24 control output panel 4 AMP RACK RKI2U Complete amplifier rack containing four L ACOUSTICS LA 48 amplifiers and V DOSC PADO4 AMP panel Also includes PADOSEC mains distribution panel Can be configured for powering V DOSC elements 2 way fill enclosures or subwoofers 5 CONTROL OUTPUT PANEL CO24 Output panel for the CONTROL RACK with Ix 84 pin MASS connector 4x 19 pin male CA COM connectors 24x female XLR inputs on the internal side x male female 4 pin XLR pair for amplifier remote control monitoring Used for connecting digital signal processor outputs and amplifier remote control monitoring to MULTI return snake lines 6 V DOSC AMP PANEL 04 Amp rack panel suitable f
134. n Figure 48 White areas are constructive interference zones gt A NCcrements Ta UU Figure 48 Destructive and constructive interference rings for a line array at observation point M L ACOUSTICS V DOSC Manual Version 3 2 10 01 110 119 We can now compare the number of sound sources inside the constructive rings to the number of sources inside the destructive rings When these numbers are almost equal sound sources are globally conflicting and produce an incoherent wavefield at M When there are significantly more sound sources within the constructive rings the same collection of sound sources produces a coherent wavefield at M It should be noted that this method is due to Fresnel he used this type of analysis to describe light interference at the beginning of the century If we repeat this analysis for different M locations we can draw a map that shows where the sound field is coherent or incoherent When it appears that there is no constructive wavefield over a given area we declare the wavefield to be chaotic If we can define an area where the wavefront is highly constructive the sound pressure level will be much higher than in a destructive area We can thus define the effective coverage of the array for this given frequency The goal for the sound designer is to clearly identify an area where the wavefield is coherent not just for a given frequency but for the whole frequency range
135. ndices elaborate on a number of technical aspects by providing additional theoretical details L ACOUSTICS V DOSC Manual Version 3 2 10 01 3 119 TABLE OF CONTENTS 0 1 WAVEFRONT SCULPTURE TECHNOLOGY FUNDAMENTALS 9 a The Sound Reinforcement Problem 9 b Wavefront Sculpture Principles sense I ER Ela 10 BIG SENE Se luti r uu xu aa en eu 0 2 V DOSC TRAINING AND QUALIFICATIONS 15 THE QUALIFIED V DOSC TECHNICIAN OYT san 5 THE GERTIEIED Y DOSC ENGINEER u mA a Seeds 15 I V DOSC THE UNIVERSAL STANDARD l6 IDENTIFICATION OF THE COMPONENTS OF THE 5 5 2 l6 a Universal Standard uu ee l6 b General V DOSC System Block Diagram 17 C V DOSG System Components seinri ae 19 LZ ELEMENT SPEEIRIEATIONS innen 24 3 V DOSERLIINGSESTEM aan er ee ee ee Mae ee ee 25 1 4 SBZTIG SUBWOOFERSPEGIFICATIONS Bei us 27 1 3 3B2 IS FEFING BAR a e
136. ndividual sources cause frequency and position dependent constructive and destructive interference This in turn leads to problems in terms of coverage pattern control intelligibility and frequency response consistency Figure 44 The Interference Problem If P is the sound pressure produced by S at point M and P the pressure produced by S at point M the complex sound pressure P resulting from the addition of the two speakers at point M is formally calculated as If both sources radiate the same pressure the real part of the complex sound pressure at is considered at time t t d c the expression simplifies to P 1 2n C where the path length difference d d od From the simplified expression it is seen that the second source causes a frequency dependent phase shift given by 09 2r f dd c When 2 where n 0 1 2 3 integer pressure cancellations occur since cos 2n I n 1 As a consequence pressure cancellation occurs for all frequencies that satisfy the condition 2f d c 2n where n is an integer L ACOUSTICS V DOSC Manual Version 3 2 10 01 107 119 For example when 0 33 m i e dt msec this yields cancellations at 500Hz 1500Hz 2500Hz producing what audio engineers term comb filtering in the frequency response The biggest problem with comb filtering is the fact that these cancellations are not consisten
137. ng from onstage In addition system predelay can also be effective in improving overall gain before feedback In some cases alignment with the instrumental backline guitar amplifier stacks kick drum is effective and the distance can be determined using simple geometry In other cases time alignment with the drum monitor monitor sidefills or the monitor front line may prove more effective Generally the loudest element on stage makes for a good time reference In smaller venues where the monitor system energy reflects off the back wall and roof then interferes with the energy generated by the band itself and then with the main PA system predelay is not as straightforward and the best results are obtained subjectively Predelay can be applied before or after performing the detailed measurements outlined in the following section just be sure that the correct relative delay is also applied to your subwoofers and to fill arrays and downfill systems Finally many users have reported good results when using program compression limiting on the main mix i e before the digital processor inputs Using a high quality compressor limiter eg SSL dbx 1605 XTA SIDD or other high quality equivalent and just a touch of compression e g 1 2 dB with a 1 5 to 2 ratio this allows the mix to sit better on the system and prevents transients from jumping out of the mix In addition by calibrating the limiter threshold to the digital processor clip poin
138. ngful Measuring two sources radiating the same signal simultaneously creates interference due to path length differences dramatically altering the L ACOUSTICS V DOSC Manual Version 3 2 10 01 87 119 frequency response In such cases the RTA display is misleading Some analyzers RTA from Sound Technology for instance provide two de correlated independent pink noise outputs This allows for simultaneous measurements on a Left Right system while avoiding path difference interference effects Positioning the measurement microphone on a stand at a typical height of between 1 2 m 3 6 ft produces a measured frequency response with a dip in the low mid frequencies This is due to acoustic cancellation between the direct wave and the reflected wave from the ground which arrives a few milliseconds later This dip in the frequency response is not due to the system and should not be equalized This can be checked by performing a second measurement where the microphone is placed on the floor and comparing the results More sophisticated measurement systems such as TDS and MLSSA allow the user to apply a time window to remove reflections from the measurement however this is can be at the expense of low frequency resolution For the above reason when there is no physical obstacle acting as a barrier between the source and the microphone it is always preferable to place the measurement microphone on the floor If the floor is absorbent for example
139. ntour of each array The Console Output Signal can be increased to up to 7 dBu at this point the amount of headroom available in the system goes to zero and the user has an indication as to the peak A weighted SPL that will be available along the isocontour Further increases in the Console Output Signal will produce a CLIP indication reflecting amplifier clip The user can also define the y coordinates for each array distance off center line and the azimuth angle in degrees i e aiming or panning angle of the array Note to simulate a centre cluster simply set Y location equal to zero b Optimization Procedure Typically the optimization procedure begins by using the ARRAYI ARRAY2 dV ARRAYI or dV ARRAY2 Cutview sheets to determine the number of array elements for Al A2 A3 and A4 H ISOCONTOUR is then used for adjustment of array separation and panning angles in order to ensure adequate audience coverage at a desired A weighted SPL and to match coverage to the audience area In some cases when horizontal coverage is an important design issue simulation can start with the H ISOCONTOUR sheet first in order to predetermine the 0 and 45 degree axes prior to more detailed Cutview simulation c Output Data Output data is directly displayed as the projection of the horizontal isocontour on the defined audience area The A weighted SPL and amount of headroom in the system are given for each array Note that the displayed ISOCONTOU
140. ocus and use the dBA estimates as a guideline only In ARRAY GEOMETRICAL DATA cells the physical dimensions of the array are displayed including the Overall Depth of the Array in the x dimension referenced to the downstage rigging point the Overall Height of the Array in the z dimension and the Bottom Element Elevation referenced to floor level The bottom element elevation is used for flying the system and the Depth Height information is useful to determine if the array will physically fit in a given space scaffold bay clearance to proscenium wall etc Please see Figure 20 for further details UPSTAGE FLY DOWNSTAGE HEIGHT MOTOR BUMPER ELEVATION SITE ANGLE SIZE OF FULL SITE ANGLE 2 SITE ANGLE 3 BOTTOM ELEMENT J ELEVATION SITE ANGLE 4 i 1 ii REFERENCE ORIGIN LEVEL i x m X AXIS a RANGE LAST ELEMENT FRONT BUMPER REAR ABSCISSA ABSCISSA Figure 20 Physical Rigging Parameters for ARRAY ACOUSTICAL PREDICTION data gives the continuous unweighted SPL of the array referenced to m and the unweighted SPL of the array at a selected distance enter the distance in the black cell L ACOUSTICS V DOSC Manual Version 3 2 10 01 52 119 This calculation is based on a 200 Hz reference frequency and correlates well with the unweighted SPL as opposed to the A weighted element by element SPL estimate The peak unweighted SPL for a s
141. of the sound source How can we achieve this goal The logical first step is to minimize the distance between sound sources By doing this for a given frequency we have a better chance of maximizing the number of sources within the first constructive ring This situation is more likely to be achieved on the main axis perpendicular to the line array as shown in Figure 49 Note that in Figure 49 the source separation is smaller than in Figure 48 so that more sources lie within the first constructive ring Deviating from the main axis as in Figure 50 the number of sources within the first constructive ring decreases progessively until there are equal numbers of constructive and destructive sources and the area then becomes totally incoherent Clear separation between coherent and incoherent wave fields defines the consistency of the main coverage region coherent wavefield defines the beamwidth Figure 49 Constructive interference rings for a condensed point source line array at observation point M L ACOUSTICS V DOSC Manual Version 3 2 10 01 I11 119 wan wm m a a 1 I i i 1 1 1 4 L 1 am aaa aan w m inco
142. on of Stacking Guidelines b Flying Guidelines The flying system is rated for a maximum of 16 V DOSC elements Particular attention must be paid to the height at which the array is flown when predicting the vertical coverage in ARRAY 2000 Cutview sheets One will discover that in many cases it is easier to optimize coverage at a certain height versus any other height As a rough guideline the elevation of a 12 element arena system is typically between 11 15 m 36 50 ft depending on the geometry of the audience Note that the angular configuration of the array should not be adjusted by considering the on axis cutview alone always consider the audience geometry off the main axis especially from 35 to 45 off axis on the offstage side It is important to be sure to check that you are not lacking in offstage coverage and require additional fill systems It is quite common to have venues where there are two sections of the audience area that have two different slopes In this case coverage of the areas which are close to the borderline must be determined carefully and V DOSC arrays should be focused differently on the two sections Finally to effectively complete any V DOSC installation either stacked or flown the operator has to carefully verify by actual measurement that the parameters in ARRAY 2000 Cutview sheets have been implemented correctly Tools that are useful for this purpose are described in Chapter 6 Detailed flying and veri
143. one once the first few cabinets are flown Note For added safety factor when flying large arrays bridling should be employed For bridling 2 steel slings are attached to the outer points on the bumper using shackles then joined using a pear ring for attachment to the motor requires 2 steel slings 4 shackles pear ring per point With three people available one person runs the chain motors while the other two attach ANGLE straps and insert SPACER blocks as the array is lifted Stagehands can be assigned the tasks of steadying the array from behind providing necessary cable slack and removing stacking dolley boards With one person on either side of the array raise the rear chain motor The first element is rigidly attached to the bumper and other elements of the array bend automatically since they are connected by the rear pivoting legs When the first element leaves the ground stop raising the array Note that the dolley boards automatically fall off as the cabinets lift off see Fig 36 q The front motor is lowered so that the front fly point on the BUMPER can be mechanically connected to the chain motor see Fig 36 r Note A m 3 ft steel extension stinger is required for the front downstage motor attachment point in order to prevent the motor chain bag from hanging down in front of the array Raise the front motor to the same height as the rear motor to level the BUMPER Attach the laser and or remote inclinometer on top
144. or 4 amplifier per rack configurations Connectors include 2x 8 pin female CA COM for loudspeaker connection male 19 pin for input signal connection Ix male I9 pin CA COM for jumping to other amp racks 2x COMB for changing between 2 way 3 way and subwoofer operating modes 2 pairs of 4x male XLR and 4x Speakon fanouts on the internal side for connecting signal to amplifier inputs and outputs 7 V DOSC AMP PANEL PADO2 Amp rack panel suitable for 2 amplifier per rack configurations Connectors include x 8 pin female CA COM for loudspeaker connection Ix male 19 pin CA COM for input signal connection male 19 pin for jumping to other amp racks COMB for changing between 2 way 3 way and subwoofer operating modes 4x male XLR and 4x Speakon fanouts on the internal side for connecting signal to amplifier inputs and outputs 8 MULTI DISTRO PANEL MD24 Stage distribution panel with x 84 pin MASS connector for connection of MULTI return snake from FOH 4x 19 pin male CA COM for distribution of Left Left Left Right Right Right signal lines x male female 4 pin XLR pair for distribution of amplifier remote control 9 BUMPER2 Flying structure for hanging a V DOSC array Can also be inverted and used as an adjustable base for stacking a V DOSC array 10 ANGLE STRAPS Used to provide spacing between V DOSC elements when stacked or flown Values 0 75 or 5 59 1 3 2 3 4
145. ourse on days off The ROOM DIM sheet is provided in ARRAY 2000 to assist in calculating cutview data from room measurements see Figure 18 for details Note the calculation of elevation Z2 is susceptible to small errors in distance measurements and should always be verified with a tape measure whenever possible Combined distance angle measurements are typically more accurate than distance only measurements when calculating Z2 L ACOUSTICS V DOSC Manual Version 3 2 10 01 49 119 Elevation Measure Laser Elevation or Laser Elevation 4 Di 02 De A D3 Room Dimension Sheet Calculation X1 X2 72 Figure 18 Parameters for the ROOM DIM Utility Sheet ARRAY In V DOSC ARRAY I cells the designer enters the number of V DOSC elements 16 maximum the elevation of the bumper and the autofocus adjust angle Normally ARRAY 2000 automatically focusses the top element to the rear of the audience geometry that is defined in Cutview Autofocus adjust can be used to adjust the overall focus of the array and DOES NOT CORRESPOND TO THE OFFSET ANGLE OF THE BUMPER For safety reasons the maximum upward tilt angle for the array given by Site to next is approximately 5 degrees The results of detailed mechanical load calculations are displayed in the MECHANICAL DATA cells in ARRAY 2000 software to determine exact array tilt angle limits NOTE Always refer to the MECHANICAL DATA cells in ARRAY 2000 to verify that safe rig
146. out cables for speaker testing CA COM to banana leads L ACOUSTICS V DOSC Manual Version 3 2 10 01 93 119 6 3 SPARE PARTS Speakers HF driver complete HF diaphragm 7 midrange speaker complete 5 speaker complete 5 speaker recone kit 8 speaker 220 mm magnet complete 8 speaker 220 mm magnet recone kit 8 speaker 260 mm magnet recone kit old style Connectors HP 2 HS 21 HP FO7I HP PHI5I HS PHI5I BEI8I HS BEI82 HS BEI8I Female Panel Mount Speaker Connector 8 conductor CC 8B EF Male Panel Mount Speaker Connector 8 conductor EM Female Speaker Connector Line 8 conductor Male Speaker Connector Line 8 conductor CC 8B FF CC 8B FM Male Extension Cable Connector Line 8 conductor CC FPM Female Extension Cable Connector Line 8 conductor CC 8B Male Panel Mount Link Connector 19 conductor Female Link Connector Line 19 conductor Speakon Connector Line 4 conductor Speakon Connector Panel Mount 4 conductor COMB Connector 25 pin COMB Connector 37 pin Accessories Locking Pin 4 5 mm diameter for U Pins Lanyard for CA GOUP45 Locking Pin 6 mm diameter for dolley board Lanyard for CA GOUP6 Cabinet handle Dolley board caster Magnet for rotating leg U Pin Left Balancier Cover plastic Right Balancier Cover plastic Bumper shackle ANGLE strap shackle ANGLE strap fitting SB
147. plifiers powering the high frequency section of the lower V DOSC elements should be progressively reduced However such attenuation results in a global loss of energy d 90 x 10 un 112 dB SPL i 4x25 ap 106 dB A am d at 30 SMS ab 27 II 1 ap no 90 20 112 dB SPL 4x5 J 103 dB A ShL j in at 30 m ku AR 2 2 90 x20 RU s ERE 18 dB SPL 8 25 A 2 106 dB A Sl at 30 Burn 10 01 47 119 L ACOUSTICS V DOSC Manual Version 3 2 Figure 16 Constant Curvature Array Examples Figure 16 shows the influence of array curvature on the SPL within the defined vertical coverage sector and how this varies relative to the frequency range Assume that the array consists of 4 V DOSC elements and covers a vertical angular sector of S If the angular spacing A is divided by 2 the value of S is also divided by 2 in the clarity domain but remains unchanged at low frequencies By comparison considering an 8 element V DOSC array covering the same sector S the SPL increases by 3 dB in the clarity domain A weighted and by 6 dB at lower frequencies unweighted d Variable Curvature V DOSC Array The ability of V DOSC to perform Wavefront Sculpture allows the designer to adapt the wavefront to suit specific audience requirements through the use of variable curvature array
148. quence of coplanar symmetry Horizontal coverage of a V DOSC array is independent of both the number of arrayed elements and the vertical configuration of the array Horizontal coverage for the entire array remains equal to the horizontal coverage angle of a single V DOSC element i e 90 from 630 to 12 5kHz To summarize a V DOSC array has a constant horizontal coverage angle of 90 in the horizontal plane from 630 to 12 5k Hz with 6 dB points at 45 off axis b Effective Coverage in the Horizontal Plane In practice strict adherence to polar specifications does not reflect the effective coverage of a sound system when it comes to the real world Although a V DOSC array is in fact radiating 6 dB less at 45 off axis this is generally not acceptable for most sound engineers and audiences A SPL window of 3 dB is more acceptable for defining the coverage of a system with constant distance and for a V DOSC array of arbitrary height the 3 dB coverage window is 70 from 630 to 12 5 kHz For sound design purposes we will use a concept that takes into account the relative distance from the array at different angles having the same SPL These isobaric constant SPL curves or isocontours are obtained by re formatting polar curves on a linear scale The horizontal projection of the isocontour can then be used directly to predict the effective coverage of a V DOSC array in the horizontal plane By overlaying the isocontour on a plan
149. ray is entirely flown can produce excessive stress on ANGLE strap fittings especially if excessive upwards tilt is applied Once flown the maximum upwards tilt is approximately 5 degrees always refer to the mechanical data provided in ARRAY 2000 to confirm that rigging limits are not exceeded Depending on the tools available there are a number of possible techniques for trimming and angling the array For trim height measurement one end of a tape measure can be fixed to the bottom wall of the bottom element at the rear of the enclosure by using some duct tape The tape measure is then L ACOUSTICS V DOSC Manual Version 3 2 10 01 78 119 used to raise the array to the proper height based on the geometrical data which was pre calculated using ARRAY and can be pulled loose afterwards Under dark conditions indoors a small flashlight can be attached at the junction between the top and the second elements The final trim angle adjustment is checked from the rearmost seats of the audience when the light can be seen through the gap separating the first and the second elements the angle of the array is correct Under daylight conditions outdoors the trim angle can be visually checked from the rearmost audience section flashlight not required If the gap between the top and second elements is clearly visible then the focus is correct Note Bushnell Rangefinder glasses can also be useful for checking gaps between cabinets at long di
150. rder between CYLINDRICAL near field Fresnel and SPHERICAL far field Fraunhofer zones can be expressed as 2 3 3 Aborder 2 H F 3H x where H height of the array in m F frequency expressed in kilohertz Iborder extension of the cylindrical soundfield with respect to the source in m In the Fresnel region the wavefront is cylindrical and expands only in the horizontal dimension nominally 90 for V DOSC The height of the wavefront is equal to the height of the array In the Fraunhofer region the wavefront is spherical and expands in both horizontal amp vertical dimensions The horizontal coverage angle is nominally 90 and the vertical coverage angle is 2 Af 0 6 D 2sin 3HF where D is the vertical coverage angle angle in L ACOUSTICS V DOSC Manual Version 3 2 10 01 115 119 The two following tables display numeric data for and D with respect the number of V DOSC elements arrayed Table 16 Border in m Between Cylindrical Fresnel and Spherical Fraunhofer Zones Freq 2 Elements 4 Elements 8 Elements 12 Elements Hz 0 9 m 1 8 5 4 border m 2 9 4 Elements 8 Elements 12 Elements H 1 8m H 3 6m H 5 4m At kHz a flat V DOSC array of 8 elements H 3 6 m radiates a wavefield that is cylindrical over distance of 19 m Beyond this distance the wavefield becomes spherical and the coverage angle is 6 i e the wavefront at kHz is defin
151. rder to maintain approved status L ACOUSTICS V DOSC Manual Version 3 2 10 01 16 119 b General V DOSC System Block Diagram A general block diagram representation of V DOSC system components cabling and signal flow is given in Figure 4 Please refer to this for a general overview of the system THEE 51 E m ist 81 85 25 9 AVA t X T N3W313 2SOQ A X 9 3245 319NV X S YOLINOWMOULNOD ualtdr Tdv asnoH 1 3991 Of div ens po TENY OF TIN TINd a ST OG 318 2 ANITA D I Pee eee eee eee eee eee eee Pe Cee eee eee eee eee ee eee EEE EEE TEE t WOQ D 5745 gt c lt stod 318v25 19 95 Fi sevsasd ese ANN ND div TANVd OULSIC LINW 8Ilcasxp DSOQ AP THA 3NI1 d IN3W313 ISOQ A X 9 3354 3I9NV X S U Wu3di dna 0 WOO 11 55082 Wd 9 SINIT LHOW 71331 174170 10414935 HO4 NOVY 34055320394 WLISIG
152. rding CA COM line assignments PADO2 and PADO4 wiring plus COMB connector wiring please refer to Tables and 2 below L ACOUSTICS V DOSC Manual Version 3 2 10 01 30 119 Table I PAD04 Wiring Chart PAD 04 COMB PANEL AMPLIFIER WIRING CHANNEL ASSIGNMENTS 19 WIRING A grd HF BE HEN gmi SUB gnd HF FILL LF FILL Gl mu rom m gio oc CHANNEL B BROWN XLR Input BLUE Speakon Output VIOLET XLR Input GREEN t Speakon Qutput WHITE XLR Input COMB WIRING COMB WIRING 26 CHANNEL A SUB 0 37 TO AMPLIFIER TO SPEAKER CONNECTOR WIRING SUB D 37 SIGNAL XLR COLOR BROWN AMPI CH VIOLET AMP2 WHITE AMP CH A ORANGE AMP CH A XLR Pl M LA 48 1 LA 48 4 1 1 1 1 BLUE CH AMPS CH A YELLOW AMP4 CHA CHANNEL B SUB 0 37 TO AMPLIFIER TO SPEAKER CONNECTOR WIRING SUB D 37 B SIGNAL SIGNAL gmd BROWN t t AMP1 VIOLET uL AMP CH B WHITE EE AMP3 ORANGE bad 1 2 3 1 2 3 1 2 d 1 2 3 LA 48 1 CHE LA 48 2 CH B LA 48 3 CHB LA 4B 4 CHE BLUE AMP1 CH B GREEN AMP CH B RED att CH B YELLOW 44 AMP CHANNEL ASSIGNMENT 4 SUB A LF FILL LOWI B SUB A HF FILL AMP CHANNEL ASSIGNMENT
153. rds the rearmost seats of the audience Alternatively from the highest section of audience area if you can see the upper wall of the top V DOSC element you are out of the coverage pattern More precise aiming can be accomplished by placing a laser pointer or similar device on the upper wall of the top enclosure A similar visual check can also be made with respect to the lower wall of the bottom element of the array to ensure that closest members of the audience are covered Connection of the array to the AMP RACKS can be performed as soon as stacking is complete To avoid confusion connect cables to the AMP RACKS first and parallel jumpers between V DOSC elements last this way reversal of cable sex is avoided i e the output of the rack is female which can be confusing to the average stagehand Remember to parallel 3 V DOSC elements maximum When unstacking the array first remove all loudspeaker cabling As each V DOSC enclosure is unstacked remove the SPACER blocks first since this makes it easier to remove the U shaped locking pins when disconnecting the rotating legs Dolley boards can be attached and enclosures directly unstacked onto their wheels b Safety Rules CAUTION NO MORE THAN 6 V DOSC ELEMENTS SHOULD BE STACKED TOGETHER ON ONE BUMPER INSTABILITY CAN OCCUR EITHER WHEN TILTING THE ARRAY OR UNDER HARD WIND CONDITIONS ALWAYS USE ANGLE STRAPS BETWEEN ENCLOSURES Always test the strength of the supporting floor each scre
154. rear ratchet straps can be employed to provide the correct angle between elements in conjunction with the ANGLE straps NOTE For safety reasons a stacked array should not exceed more than 6 elements high The DELTA PLATE rigging accessory is available to allow for pan adjustment of flown V DOSC arrays The relative action of the 2 rear motors controls the rotation of the array as shown in the figure below MOTEUR 2 MOTEUR wee 4 MAN 22 CHAINES i MOTEUR 3 BUMP DELTA V DOSC BUMPER V DOSC 16 max La fonction du BUMP DELTA est de faire pivoter le systeme V DOSC en ajustant la longueur des chaines a l aide des moteurs et 2 L ACOUSTICS V DOSC Manual Version 3 2 10 01 26 119 1 4 SB2 18 SUBWOOFER SPECIFICATIONS Dimension WxHxD 1 300mm x 550mm x 700mm 51 2 x 21 7 x 27 6 Weight 106 kg 234 lbs j 26 Figure 8 SB218 Subwoofer Front and Rear Views The SB218 subwoofer enclosure has been specifically designed to complement V DOSC although it may also be used in other applications Phase response of the V DOSC element and the SB218 are compatible throughout the 80 200 Hz region providing optimum coupling for a wide range of crossover frequencies With the addition of SB218 subwoofers the low frequency response of the V DOSC system is extended down to 25 Hz The enclosure is of bass reflex type with a large area port enhancing large signal dynamic capability
155. rray cannot be tampered with by unauthorized people Always cover motors with plastic in outdoor installations where motors may be exposed to rain ANGLE straps are required at all times When V DOSC arrays are flown with no tilt on the BUMPER and top element all weight is borne by the rear pivoting legs However as the array is tilted upwards weight is also borne by the ANGLE straps The more the array is tilted upwards the more weight is carried by the ANGLE straps For this reason never tilt the array upwards by more than 5 degrees For the same reason always fly the array flat then apply tilt once all cabinets are flown Never overtighten the ratchet straps especially if the array is tilted upwards L ACOUSTICS V DOSC Manual Version 2 00 30 11 01 VDOSC MANUAL V3 2 1001 doc 85 121 5 V DOSC SYSTEM OPERATION WARNING The V DOSC system is capable of producing high sound pressure levels Hearing loss or damage can occur with prolonged exposure to high SPLs Please operate your system responsibly at all times An SPL meter on the mix console is highly recommended as a reference Prior to describing system operation and tuning procedures subjective criteria are first considered in order to discuss the objectives of system setup 5 1 SUBJECTIVE LISTENING AND TONAL BALANCE The overall tonal balance of the system depends on both the musical program and on the target SPL Leq or average SPL For large scale rock concerts typical sound
156. s Since each V DOSC element produces a flat isophasic wavefront it is possible to couple as many elements as is needed in one vertical sector in order to focus energy in this direction This is accomplished by reducing the angular spacing A between elements within this sector or conversely by increasing A up to a maximum of 5 in order to lower the SPL in another direction This is the basic principle that allows energy to be more uniform throughout the audience Shaping the vertical isocontour is the key to Wavefront Sculpture Technology The ARRAY 2000 spreadsheet allows the designer to shape the vertical isocontour of a V DOSC array by displaying the results of various angular spacing selections and the following section gives complete details on variable curvature array design 2 3 COVERAGE PREDICTIONS USING ARRAY 2000 L ACOUSTICS has developed a fast easy to use prediction spreadsheet named ARRAY 2000 ARRAY 2000 operates under EXCEL version 97 and is available for both Windows and Macintosh The spreadsheet can predict coverage for flat constant curvature and variable curvature arrays The first four worksheets represent vertical cut views section elevations of the audience in the xz plane and show the intersection of the vertical aiming direction of each element with the audience impact zones The direction of each element is calculated automatically according to the user input angles A All angles are referenced with respe
157. s improved up close while at the same time bass coverage is smoother throughout the audience For a single horizontal line of subs SUB ARC presets are provided for all digital processors to provide a useful starting point Delay arc processing is also useful for larger systems involving LL L R and RR arrays with associated vertical subwoofer line arrays in conjunction with a central horizontal line array see Figure 24 To date it has been found that the optimum arc radius is equal to half the length of the central line array Delay taps are calculated geometrically based on this arc radius and the physical distance of a given subwoofer group off the center line reference y axis An EXCEL spreadsheet tool to perform delay and offset calculations is available in ARRAY SUB ARC The LL and RR subwoofer line arrays are then time aligned to the central horizontal line by taking measurements on their main aiming axis In practice the center subwoofer group acts as the time reference is applied to compensate for any offset due to physical placement and to include predelay for time alignment of the subwoofers with the instrument backline kick drum monitor sidefills or monitor front line as desired The predelay is then added to the calculated relative arc delays T2 T3 and T4 in order to maintain the electronic subwoofer arc L L and arrays are delayed by T4 TI L and R arrays are delayed by T3 TI to maintain proper alignment with t
158. scia Eee 74 Figure 36 Photo sequence showing the steps involved in flying V DOSC 85 Figure 37 Array Elements of 3 Way System 93 Figure 38 Array Elements of 4 Way System Design 93 Figure 39 Recommended Installation Tools 96 Figure 40 V DOSC Element Line Drawing er an 98 Figure 41 SB218 Subwoofer Line Drawing 99 Figure 42 V DOSC Flying Bumper Line Drawing 100 Figure 43 SB218 Flying Bar Line Drawing 101 Figure 44 Ie Interference Problem ee eek 108 Figure 45 Comb filtering due to path length differences between 09 Figure 46 Destructive interference ring for a line array at observation point 110 Figure 47 The effect of varying frequency and listener position on Fresnel rings Figure 48 Destructive constructive interference rings for a line array at observation point M L ACOUSTICS V DOSC Manual Version 3 2 10 01 7 119 Figure 49 Constructive interference rin
159. separate subwoofer processing L ACOUSTICS V DOSC Manual Version 3 2 10 01 63 119 d The SB218 as an Extension of the Array In this situation the system is operated in 4 way mode and the input signal of the subwoofer is identical to that of the V DOSC array The 18 speakers of the SB218 and the 15 section of the V DOSC enclosure operate over the same frequency range and identical crossover points are used in order to avoid phase shift problems Crossover presets with the X suffix X stands for eXtension should be used since these presets provide dedicated equalization for low and subwoofer channels For 4 way operation the operator should optimize physical coupling of the subwoofer and V DOSC arrays This is practically achieved by keeping the SB218 array physically close to the V DOSC array Two configurations are proposed Fly the SB218 array on the offstage side no more than 3 m from the V DOSC array axis to axis Stack the SB218 array under beside offstage or behind the V DOSC array no more than 3 m from the V DOSC array axis to axis OR Low Flown SUBS Frequency extension lt 3m Stacked SUBS Stage Stage Figure 27 The subwoofer array as an extension of the V DOSC system Arrays are coupled to extend the low frequency response with separation or offset of no more than 3m recommended Dedicated presets have the X suffix and 200 Hz low pass filtering is employed for the subwoofer section effective 120 Hz LPF wi
160. should be on the bottom and the rear V DOSC logo in the correct orientation Adjust the front to back position of the enclosure on the BUMPER by aligning the Aeroquip flytrack sections of the enclosure and the BUMPER Mechanically connect the first element to the BUMPER by lifting the rotating legs of the BUMPER up and locking them into the rear rails of the V DOSC element using the U pins Verify the tilt angle for the first element using a digital protractor or analog inclinometer use the stacking runner recess on top of the cabinet for alignment of the measurement tool and perform any required tilt adjustments using the screwjacks A second V DOSC element is then stacked on top of the first and mechanically connected using the rotating legs and U pins in the same way The two elements are then connected using the desired ANGLE straps and two SPACER blocks are tightly wedged in between the first and second elements to remove all slack in the ANGLE straps this sets the correct tilt angle for the second element Never use a single SPACER block in the center of the cabinets the wood thickness is only 15 mm at this point and the overall weight of the stack could cause damage to the bottom enclosures Verify the tilt angle for the second element using a digital protractor or analog inclinometer and perform any necessary adjustments NOTE Since the rear edges of the cabinets are touching when enclosures are stacked this introduces an additional
161. signal processor NOTE For the CROWN MA 5000VZ in the 1 4 Vrms input sensitivity setting not recommended since this corresponds to 36 dB gain this is equivalent to 5 dBu so limiter thresholds must be lowered It is highly recommended that users modify their CROWN MA 5000VZ amplifiers to 32 dB gain in accordance with the V DOSC Network Standard Apart from limiter calibration issues gain structure differences become an issue when using a mixture of LA 48 and MA 5000 amplifiers within the same system if all amplifiers are not at 32 dB standard gain XTA and BSS limiter thresholds are user accessible and should be set at 9 dBu for LA 48 or 5 dBu for CROWN in the 1 4 Vrms setting for all bands Exact settings will depend on individual engineer preferences and the type of music or application which in turn determines how hard the V DOSC system is being operated When additional crossover limiting is desirable limit thresholds can be set Ito 3 dBu below the amplifier input sensitivity This further prevents transients from driving the amplifier into clipping which can result in speaker damage NOTE Setting limit thresholds to the amplifier input sensitivity is important since this calibrates the output meter display of the crossover to correspond to the amplifier clip point This gives the system operator a direct visual indication as to how hard the system is being operated The L ACOUSTICS LA 48 is an excellent power match for the V DOSC
162. stances Coverage up close can be checked by visually checking to see that the top wall of the bottom enclosure is in line with the desired aiming angle for the closest members of the audience For final angle adjustments a pair of radios is useful while one person walks the room and visually inspects the array while a second person operates the motors A more precise technique is to use a laser pointer or laser level attached to the top of the first element Trim angle adjustments are then given by the focus of the laser on the audience no walking to the back of the venue is required although a set of binoculars can be useful in locating the laser beam Coverage up close can be checked by attaching the laser device to the lower wall of the bottom enclosure Obviously array focus using lasers is difficult to perform outdoors under daylight conditions As described above mounting a remote digital inclinometer on the top element and using a handheld digital inclinometer is very useful for tensioning ratchet straps and verifying that the overall vertical coverage angle of the array matches what was simulated in ARRAY 2000 Once the system is flown to trim the tilt of the array can be set using the remote inclinometer and setting the tilt Site Angle It is important to perform this final adjustment once the array is at the correct trim height since chain motors typically do not run at exactly the same speed For all of the above alternatives sev
163. stem The origin of the x axis is referenced to the top rear corner of the top element while the origin of the z axis is at floor level i e the x axis is distance or range along the desired array axis and the z axis is height above floor level A second cut view can also be specified at an off axis angle within the coverage pattern of the array Typically the second cut view is taken at 45 offstage in order to confirm coverage throughout all portions of the audience The listening level cell is the effective hearing level or ear height relative to floor level 1 2 metres for a seated audience 2 metres for standing Cutview Cutview 2 Plan View Section View Figure 17 Defining Cutview Dimensions Although detailed blueprints are not necessarily required the more information that can be obtained on a venue for defining the audience geometry the better Typically plan and section views are available for most venues upon request In situations where such documentation does not exist there are a number of options use a tape measure or laser range finder on site to perform dimensional measurements Alternatively L ACOUSTICS has had good results with the Bushnell Yardage Pro 600 for field measurements Apart from being useful for defining room geometry this tool can also be used for determining delay time settings during system tuning for locating laser beams during array trim and angle adjustment and even on the golf c
164. system and the LA 48 clip limiter is sonically very transparent The LA 48 clip limiter works by monitoring the output and comparing the distortion produced between the input and output of the amplifier If the distortion exceeds 1 THD for any reason voltage or current clipping the limiter reduces the input signal proportionally 2 msec attack 150 msec release Under normal operation LA 48 clip limiting is inaudible and L ACOUSTICS recommends leaving the Channel A and B clip limiters switched on rear panel button depressed at all times NOTE The LA48 has a comparatively low input sensitivity 9 5 dBu versus the Crown 5000 5 dBu in the 1 4 Vrms setting This means that in practice it can be necessary to equally scale up the individual crossover channel output gains in order to have sufficient drive capability note this has been done for Version 5 preset library release see section 1 10 b for details It is far better to use the output drive capability of the processor DACs and analog output section rather than overdrive the input ADCs so do not be afraid to increase the channel output gains in order to achieve a comfortable gain structure This will also depend on how hot or cold the FOH mix engineer likes to run his console When in doubt disconnect all loudspeaker cables and run pink noise from the console at nominal level through the crossover to the power amplifiers and examine crossover input output levels crossover limiter indi
165. t this provides an additional level of system protection by preventing digital clipping of the processor inputs Program compression limiting before the processor inputs also provides another level of control when dealing with over zealous guest engineers in a festival situation 5 2 MEASUREMENT PROCEDURE Tuning and equalization of a V DOSC system is a relatively simple procedure i e given the prediction tools and array design concepts outlined in Chapter 3 the precise flying stacking procedures described in Chapter 4 and dedicated digital processor presets an excellent starting point for system tuning is immediately obtained upon installation Generally speaking little equalization is required and one third octave real time analysis RTA is sufficient for equalization measurements Alternatively TDS MLSSA SIM SMAART or Spectrafoo analysis can be used to obtain higher resolution or for time delay measurements When properly installed coverage should be very homogeneous and 3 measurement locations are sufficient for system tuning one in the near audience area one at the mix position and one at the rear of the audience It should be verified that the global shape of the frequency responses at these locations is similar before proceeding to perform detailed equalization a Measurement Caveats Interpreting measurements correctly requires awareness of a few pitfalls Here are some typical ones Measurement of one source is meani
166. t Focus By Adjusting For Equal Spacing Typically optimum coverage is obtained iteratively by varying the height of the array and the element angles to next 2 to next etc The designer manually performs the optimization by visually referring to the spacing between audience intersection points after making changes to the array Once equal spacing has been achieved the designer has successfully optimized the performance of the system by shaping the array s vertical isocontour to match the geometry of the audience Angle strap values bottom element elevation site angles for top and bottom elements and trim height parameters are then recorded and used for actual installation of the system see Output Data Note There is a difference between NOMINAL ANGLES for FLOWN versus STACKED arrays When V DOSC enclosures are stacked the rear corners of cabinets are touching due to gravity and when flown there is a small gap This difference approx cm over the depth of the cabinet corresponds to an additional I degree for stacked versus flown systems Therefore to model stacked system coverage users should enter 1 75 2 3 3 0 4 0 5 0 do not use instead of 0 75 1 3 2 0 3 0 4 0 5 5 c Output Data In the columns adjacent to where angle strap values are entered the site angles i e what you would measure if you put a digital inclinometer on 1 2 etc elements and the wavepath throw distance for each element are tabulated
167. t devoid of shortcomings Typically the problems are as follows Tonal balance has an exaggerated low boost for the closest members of the audience Locating front fill apron fill loudspeakers close to the subwoofers can help offset this Low end can spill back onstage and cause feedback problems for the stage monitoring system Restricted projection due to audience absorption and modified thermal conditions this problem is likely to occur with any ground stacked configuration Mutual radiation pressure may wear the drivers located at the center of the array For the central ground stacked configuration the subwoofers are not acoustically coupled with the main V DOSC arrays They are processed separately and are fed with an independent signal from an auxiliary output See section c for a description of preset options and sub drive processing d E 111 1 Figure 28 Central location ground stacked subwoofer configuration L ACOUSTICS V DOSC Manual Version 3 2 10 01 65 119 g Electronic Delay Arc Processing For large scale applications an interesting technique for controlling the central ground stacked horizontal line array is to use delay processing to electronically arc the array Cabinets are grouped in blocks of four symmetrically about the central axis and the delay is progressively increased for offstage groups Electronic arcing in this manner can successfully decouple sections of the array so that tonal balance i
168. t with frequency since the time differences change depending on the observer location M SPL fg 3f 0 fo To f Figure 45 Comb filtering due to path length differences between sources As discussed in Section 3 la the principles of 2 source interference can be used in sound design when considering multiple V DOSC arrays since in effect the main and offstage V DOSC arrays act as 2 coherent sound sources When a separation of 6 8 metres is maintained between the 2 V DOSC arrays this shifts the first null seen in Figure 45 fo down to approximately 15 25 Hz and this cancellation is inaudible The second and third nulls 3fo 5fo tend to be filled in or masked by room reverberation Higher frequency cancellations 7fo and higher are too tightly spaced for the ear to resolve plus focussing the aiming axes of the two arrays at different angles helps to minimize the area over which comb filtering interaction takes place L ACOUSTICS V DOSC Manual Version 3 2 10 01 108 119 APPENDIX 2 FURTHER EXPLANATIONS REGARDING WST CRITERIA A detailed formulation of Wavefront Sculpture Technology Criteria was developed in Sound Fields Radiated by Multiple Sound Source Arrays AES preprint n 3269 presented at the 92nd AES convention in Vienna March 1992 Further theoretical research was developed in Wavefront Sculpture Technology prepared for the 111 AES Convention NYC Sept 2001 preprint not available at the time of this manual revision
169. th additional channel eq In both cases time alignment should be optimized via measurement see Section 5 2 b When subs are stacked underneath as an extension this has the benefits of exceptional vertical pattern control at very low frequencies combined with perfect coupling since almost no discontinuity in low frequency radiation occurs from the top of the array to the ground WARNING This set up only works when using the correct preset Because of the nature of the filters the subwoofers do not sound as most sound engineers would expect Listening to the system section by section may confuse them It is important for the CVE to maintain control of the adjustments in order to prevent any gross errors due to misalignment The collective performance of all speakers should normally produce incomparable low frequency far field projection 4W presets can be also be used when subs are physically installed as an extension of V DOSC although with 80 Hz high pass filtering there is reduced low end energy coming from the V DOSC system itself At the same time there is a higher degree of excursion protection for the low section due to the 80 Hz high pass filter Apart from these technical issues the choice between 4W or X presets is a matter of subjective taste e Flown Subwoofers The benefits of flown subwoofers include L ACOUSTICS V DOSC Manual Version 3 2 10 01 64 119 Improved low frequency summation and throw when subs are flown close to
170. the first case the angle between all adjacent elements is constant while for the second case it varies within the defined range of 0 to 5 L ACOUSTICS V DOSC Manual Version 2 00 30 11 01 VDOSC MANUAL V3 2 1001 doc 46 121 Constant Curvature V DOSC Array For a constant curvature array the vertical coverage angle is nominally N x where N is the number of elements in the array and is the constant angle between each adjacent element For example a curved array of 8 V DOSC elements can provide a maximum vertical coverage of 8 x 5 40 while still satisfying WST criteria The constant curvature array is the simplest type of curved V DOSC array This configuration should only be used for smaller sized arrays or when the geometry of the audience is unknown Since an array of constant curvature radiates the same amount of energy in all directions over the nominal vertical coverage range N x this type of array is of practical use only when the entire audience is sitting at the same distance from the array However in most venues a V DOSC array will have to cover an audience sitting at varying distances from the array A constant curvature array would produce excessive SPLs in the first rows compared to the remote audience even when the vertical coverage angle is correct Therefore a constant angular spacing between elements is generally not useful for most applications If this configuration is used the gain of the am
171. the V DOSC arrays since the subwoofers act as an extension of the system Due to the longer wavelengths at low frequencies floor coupling is still obtained with flown subwoofers Supposed reductions due to lack of floor coupling are offset by reduced audience absorption plus the reduction of subwoofer energy for the first 20 metres is actually due to the vertical directivity that is introduced by vertically line arraying subs not lack of floor coupling Time alignment of subwoofers to the main left right V DOSC arrays is greatly simplified since the physical path length difference problem of ground stacked subs versus flown V DOSC is no longer a factor that varies with listening position Overall this improves low frequency summation and coherency for the entire audience Elimination of local low frequency buildup for the audience down front in the first few rows Adding several ground stacked subs per side or a centre line will provide sufficient low end impact for the first 20 metres Cleaner staging and better sightlines f Central Location Ground Stacked This configuration optimizes the radiated energy All subwoofers are acoustically coupled and the floor if solid concrete for instance acts as a mirror and virtually doubles the number of subs Given the same number of subs the overall pressure obtained by ground stacking in this manner is simply not achievable in any other configuration The central ground stack solution is no
172. truck packing for a variety of trailers of standard sizes Flying a V DOSC array is particularly easy fast and secure The V DOSC element features a unique flying system where built in flying hardware extends from cabinet to cabinet to the hanging points on the BUMPER flying structure in a caterpillar like fashion Two rotating legs Balanciers are located on the rear of each cabinet and are physically attached to the other cabinets using U pins Axfixe Cabinets are physically connected while lined up on the floor and the complete array is flown all at once in comparison with other systems where cabinets are flown row by row The only external L ACOUSTICS V DOSC Manual Version 3 2 10 01 24 119 parts needed are ANGLE straps and SPACER blocks these accessories are used to adjust the angle between adjacent elements in the array see Chapter 4 for full details on flying and stacking V DOSC The bandwidth of the V DOSC array is 50 Hz to 20 kHz 3 dB For rock applications the addition of SB218 subwoofers is recommended in order to extend the response to 25 Hz and to increase the available headroom in the extreme low frequency range Please see Section 3 4 for full details on using V DOSC with subwoofers 1 3 V DOSC FLYING SYSTEM ES ME Lu lo Dimension WxHxD 1262mm x 140mm x 1100mm p Ber 49 5 8 x 5 4 8 x 43 3 8 4 per Weight 61 5 kg 135 6 Ibs _FLYTRACK Figure 7 V DOSC BUMPER The BUMPER flyin
173. ts that their transport handling and installation would simply not be practical In practice conventional horn loaded loudspeakers are typically assembled in a fan shaped array following the angle determined by the horizontal coverage angle of each enclosure in an attempt to reduce overlapping zones that cause destructive interference With this type of arrangement the optimum clarity available in one direction can only be provided by the individual enclosure facing in this direction Attempts at flattening the array in order to achieve greater throw and higher sound pressure levels results in severe interference in an uncontrolled way affecting coverage pattern control intelligibility and overall sound quality Even when arrayed according to specification always an optimum compromise since the polar response of individual horns varies with frequency the sound waves radiated by individual loudspeakers do not couple coherently see Appendix thus the conventional system approach is fundamentally flawed Furthermore the chaotic sound fields created by interfering sound sources waste acoustic energy thus requiring more power than a single coherent source would in order to achieve the same sound pressure level To illustrate this consider what happens when we throw pebbles in the water If we throw one pebble into the water we can see circular waves expanding from the place where it disturbed the surface If we throw a handful of pe
174. ve to fulfill the second WST criterion at higher frequencies since it is not possible to satisfy the first one for these frequencies This is achieved by mounting a DOSC waveguide on the exit of each driver this shapes the wavefront into a rectangular constant phase source Arraying DOSC waveguides and drivers then creates a flat isophasic ribbon that fulfills the second WST criterion i e the overall radiating area is more the 80 of the target area provided that the angle is less than 5 degrees between enclosures L ACOUSTICS V DOSC Manual Version 3 2 10 01 113 119 APPENDIX 4 HOW DOES THE DOSC WAVEGUIDE WORK There is no mysticism surrounding the DOSC waveguide It is simply the result of careful analysis of the wave path through the waveguide and the resulting wave front shape CONICAL HORN CONSTANT DIRECTIVITY HORN Figure 52 Horn Generated Wavefronts With respect to Figure 52 the wavefront emerging from a horn is the result of constant time arrivals for all possible wave paths radiated by the driver exit The two examples shown in Figure 52 produce more or less curved wavefronts that obviously cannot meet the second WST criterion Figure 53 DOSC Waveguide Internal Section By comparison the DOSC waveguide acts as a time alignment plug delaying the arrival times of every possible wave path to be the same value at the rectangular exit of the device The internal plug is a truncated conical piece that looks like a tomah
175. verage anne 58 3 25 MERED ORFLOWN Nenn 57 a stacking Guidelines 5 arate siete tar RE Ba 58 BD Flying Gul de e 59 3 3 THE LEFT RIGHT CONFIGURATION u han aaa an 60 The St andard Coniie ratiou u uuu ku us an 60 b Tradeoffs Between Intelligibility and Stereo Imaging 62 3 4 SUBWOOFERS asien 63 a General Guidelines for the Use of Subwoofers 63 b Combining V DOSC With Subwocotfers 63 C The Subwoofer asan uuu css cise abre deti eoe dae e obe ha eet T 63 d The SB218 as an Extension of the Array EB 65 Flow SUBWOBIErS nee 65 b Central Location Ground StIcked ise eee I BER Ha 66 h Other Techniques for Reducing Centre Buildup 67 3S DELAT STS ERE ee 69 a Delay System Installa tiO mer ra aq 69 3 6 SAMPLE ARRAY CONFIGURATIONS E E AEE 70 a Long Narrow Audience Format lat 70 b Wide
176. vides constant 32 vertical coverage above F 1388 Hz with narrower coverage between F 201 Hz and and with a broadening of coverage below F subject to the laws of diffraction that govern spherical wave propagation degrees nominal coverage NA F F frequency Figure 56 Illustration of the variation of vertical coverage angle with frequency L ACOUSTICS V DOSC Manual Version 3 2 10 01 117 119 APPENDIX 7 V DOSC RIGGING CERTIFICATION Affair Heil Acoustics V DOSC System B REAU Hanging system of loudspeakers VERITAS N CR51B950374C 1 PURPOSE OF THE REPORT The present report deals with an hanging system device of loudspeakers for the V DOSC system of HEIL ACOUSTICS Our mission consists in checking the stability of the works in reference 10 applicable French and European standards We have checked the shop drawings to be used for the manufacturing A site visit enabled us to check the manufacturing of an hanging system and to be present at a hoist intervention n a real usage configuration 2 REFERENCES Applicable rules Rules 66 for steel AL rules for aluminium July 1976 CB 71 rules for timber speaker boxes e European rules for steel Eurocode 3 DAN Rules of the F d ration Europeeene de Manutention for the sizing of the structure specified on drawings b Load assumption Proper weight of the bumper 62 daN Fitted speaker 108 daN In a maximum configuration
177. view model of the venue the sound designer can adjust the aiming axis or panning of each array to get the best coverage results for a given audience layout The horizontal isocontour for V DOSC is averaged from 630 Hz to 12 5 kHz since the horizontal coverage of the array is stable and remains constant over this frequency range This also gives good consistency over what we call the clarity range since it is this bandwidth that is largely responsible for the perceived intelligibility For lower frequencies the isocontour is not preserved and becomes more omnidirectional as the horizontal coverage angle increases at lower frequencies For simulation purposes L ACOUSTICS provides horizontal isocontour data in the H isocontour sheet in ARRAY 2000 For further details on how to use this data in sound design please see Section 2 3 L ACOUSTICS V DOSC Manual Version 3 2 10 01 44 119 Figure 14 Horizontal V DOSC isocontour averaged from 630 Hz 16 kHz 50 Figure 15 Horizontal V DOSC isocontour averaged from 32 Hz 630 Hz L ACOUSTICS V DOSC Manual Version 2 00 30 11 01 VDOSC MANUAL V3 2 1001 45 121 2 2 WAVEFRONT SCULPTURE IN THE VERTICAL PLANE a Flat V DOSC Array Flying or stacking V DOSC elements with no angular spacing between enclosures produces a flat array In this case the whole array behaves acoustically like a vertically oriented flat continuous isophasic ribbon and radiates a CYLINDRICAL WAVEFIELD The cylindric
178. well from venue to venue Essentially the dV DOSC and V DOSC systems serve as an accurate reference monitor allowing the FOH engineer to concentrate on the fine details of his mix A common problem with FOH engineers who are not familiar with V DOSC and dV DOSC is the tendency to over equalize the midband section since they are not accustomed to the nearfield listening experience over this frequency bandwidth The CVE accompanying the V DOSC or dV L ACOUSTICS V DOSC Manual Version 3 2 10 01 86 119 DOSC system should attempt to dissuade over equalization and educate the guest engineer whenever possible A better solution is not to equalize the mid band section but to simply reduce the level of vocals etc in the mix Several strategically placed parametric notches can be highly effective in compensating for room reverberation modes For performing this equalization use the parametric filters available on the inputs of the digital processor for higher resolution not the graphic In a festival situation an effective approach is to perform basic equalization using the input parametric filters then turn the system over to the guest FOH engineer with house graphic eqs set flat Typically guest engineers are more comfortable with a graphic eq for quick adjustments on the fly After each act the graphic can be reset for the next engineer System predelay is commonly used to improve the combined integration of the main FOH system with the sound comi
179. while minimizing non linearity due to port turbulence The 8218 contains 2X 18 drivers connected in parallel with a nominal impedance of 4 ohms Rear panel connection is made via a 4 pin Speakon connector and SUB CABLEs are used for connection to amplifier racks The SB218 has two side mounted vertically oriented Aeroquip flytrack sections for flying enclosures vertically in a line array configuration as an extension of the V DOSC array L ACOUSTICS V DOSC Manual Version 3 2 10 01 27 119 1 5 SB218 FLYING BAR The flying system for constructing an SB218 line array consists of one steel bar four shackles and two chains incorporating Aeroquip studs The Aeroquip studs are connected to the Aeroquip flytrack located on each side of the SB218 The flying assembly is rated for up to 8 subwoofer enclosures at a 5 1 safety factor Note when attaching shackles and fittings to the chains it is easier to preattach prior to flying Lay the chain out flat and remove any twists Shackles are then attached every chain links i e with a separation of I I chain links between each shackle Figure 9 SB218 Flying Bar L ACOUSTICS V DOSC Manual Version 3 2 10 01 28 119 1 6 V DOSC AMPLIFIER RACK Figure 10 LLACOUSTICS Amplifier Rack RKI2U The L ACOUSTICS amplifier rack RKI2U is 12 rack units high and contains 4 L ACOUSTICS LA 48 amplifiers Overall external dimensions are 77 cm high including casters x 61 cm wide x 58 cm deep 30 3 x 26 4 x
180. wind sound wave refraction due to temperature and humidity gradients or very large distances gt 150 m may create the need for a delay system typically in open air situations The use and tuning of delay systems in open air situations is far from straightforward since the correct delay time setting is typically valid only over a limited area In addition wind temperature and humidity variations along with other random phenomena can affect the speed of sound thus invalidating the delay time settings a Delay System Installation There are a few principles that should be applied when installing delay systems Avoid installing delays wherehe adjustments cannot be made secure use security panels or password protection whenever possible 2 Overdelaying up to 15 ms is acceptable due to the Haas effect and may provide a safety margin Greater than 5 ms is not acceptable since the delayed sound will be perceived as a distinct echo behind the main signal In some situations speech it is advised to underdelay in order to optimize the off axis intelligibility and clarity behind the delayed system 3 Spread different sources with different delayed waves instead of grouping them in a single location This allows for broader coverage by the delayed sources and produces more homogeneous SPL over the delay covered area If possible physically locate the delay positions along an arc with a radius equal to the distance from the furthest offstag
181. wjack may bear up to a 350 kg load Use plywood sheets or steel plates under individual screwjack feet in order to help distribute the load The maximum downward or upward tilt angle of the bumper is 12 degrees When stacking on scaffold platforms for delay towers omitting the front 2 screwjacks and ratchet strapping the BUMPER to the platform can improve stability L ACOUSTICS V DOSC Manual Version 3 2 10 01 75 119 4 2 INSTALLATION OF A FLOWN SYSTEM a Flying and Connecting Flying a V DOSC array is fast and easy When properly prepared and organized handling time can be significantly reduced especially in comparison with conventional systems Installation is optimum when 3 people are available 16 V DOSC can be flown in 20 minutes although it is possible for 2 people to fly V DOSC Please refer to the sequence of photos shown in Figure 36 with respect to the following description of flying procedures Preliminary Preparations All geometric data for the flying the array i e bottom element elevation inter element angles site angles has been pre calculated using ARRAY 2000 and mechanical data has been checked for safe rigging conditions Two independent flying points are available one behind the other with a spacing of 05 meters 43 4 between points and with the desired onstage rotation angle for the array Alternatively three points can be used along with a swivel shackle connecting a delta plate to the rear BUMPER

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