Bosch EVI-15
Contents
1. EVI 12 EVI 15 and EVI 28 Loudspeaker Systems Applications Guide Welcome to the world of Vari Intense horn technology from Electro Voice This Applications Guide is not intended as a very intense descrip tion of installation procedures but more as a partial description of applications and a discussion with the designer to help you understand this revolution ary technology and use the Electro Voice Vari In tense systems to install better sounding systems and significantly reduce time and material costs In a nutshell here are the major advantages of the new EVI systems e Rectangular coverage pattern Traditional horns deliver an elliptical pattern to the floor VI horns deliver a rectangular pattern which helps to fill in the corners of the room No more costly delay lines or cheap seats Even SPL front to back The unique patented throat and flare struc ture of the VI horn delivers a 6 10 dB hotter signal to the rear of the room eliminating ear strain at the back of the seating area and pain ful ears at the front Greater Intelligibility VI horns deliver sound to fill only the floorplan providing uniform direct field SPL and an order of magnitude less energy into the reverberant field This provides an increase in mid to high frequency intelligibility of 6 dB in most applications One horn replaces two With VI technology we ve eliminated the de structive interference which occurs betwe2. and inappropriate for highly reverberant rooms but the plots of the direct field SPL and its accompanying C50 ratio show a significant advantage to the VI system over a conventional 60 x 40 system As we all know high Q only helps when the polar response fits into the listening space as closely as possible Please keep this in mind when using Q as a bench mark for system intelligibility For those unfamiliar with the term C50 itis a measure of intelligibility defined by the acoustic power in the room in the first 50 msec divided by the power from 50 msec to infinity expressed in dB The minimum recom mended level of intelligibility is 0 dB roughly equiva lentto 10 Alcons A Note on Simulation Software Data files for AcoustaCADD and EASE are available from Electro Voice s BBS by special request or on Electro Voice s Website http www electrovoice com The figures have all been produced in EASE but with the current 10 resolu tion of the software much of the 2 resolution data we collect has been lost in the required averaging translation to the 10 degree format The net result is that 3dB of long throw SPL and 1 5 2dB of side fill level has been lost A higher resolution data file is needed to provide a real world realistic simula tion Figure 5 shows the raw 2 polar data with the averaged 10 data superimposed Also shown are floorplans from our 2 modeler DCSO the 5 degree AcoustaC ADD and 10 de
3. have no problems with interference and maintain very good tonality even far to the sides and to the back outside the equal SPL pattern area This effect is due to the precise matching of directivities in the midrange and treble giving aconsistent although noticeably quieter fre quency response out to nearly 50 feet in width and 65 70 feet in length from the same 18 foot height and 0 aiming angle This has the advantage of pro viding a much more uniform power response into the reverberant field ensuring that the inevitable reflections minimized by the VI concept are con sistentin tonal quality EVI 28 Installation The EVI 28 makes use of the same high fre quency horn as the EVI 12 and EVI 15 but in cludes a pair of high power high efficiency 8 woof ers in a very compact package The system 1s pro vided with a 2 000 Hz passive crossover featuring tweeter protection and a proprietary passive equal ization circuit that provides frequency shading am plitude shading and time delay to the two woofers An Acoustic Lens Filter on the grille helps to elimi nate spurious lobes and provides a degree of acous tic loading These features heavily modify the polar response of the two woofers providing an extremely uniform polar pattern with a shape that matches the VIhorn s unique SPL profile They also smooth the transition between woofers and the horn to mini mize horizontal lobes providing amazingly even coverage thro
4. re F T O D x amp e C5 Direct Field SPL A I eS yeh ee east cSt en en E Ho o q sE PER XS mimi Ln Lon n qu pu 13 IN A TYPICAL UNDER BALCONY APPLICATION THE EVI 28 IS MOUNTED WITH THE TOP SURFACE 8 PARALLEL TO THE FLOOR FOR A 65 FOOT THROW WITH RESTRICTED SPL INTO THE REAR WALKWAY 10 FEET 1 IN A ICAL SMALL ROO APPLICATION THE EVI 28 IS MOUNTED Figure 12 SO THE 5 DEGREE DOWN ANGLE POINTS TOWARD THE FAR WALL AT A LI E ABOVE STANDING OR SEATED HEAD HEIGHT FOR A 30 FOOT THROW FROM A 9 FOOT CEILING THE SPL DROPS OFF QUICKLY PAST E NEARFIELD ANGLE i f T 5 0 40 00 9 FEET di L f f ZE dE Ey E C C C C C C 1 J 1 1 j 7 ey 30 FEET Figure 14 BOLTS AND CABLING CHAINS MUST N BE RATED FOR OVERHEAD LIFTING SEE TEXT Figure 13 BOLTS AND CABLING CHAINS MUST BE RATED FOR OVERHEAD LIFTING NOT SUPPLIED PULL UP STRAP ATTACHED TO 3 8 16 FORGED SHOULDER 3 8 16 FORGED SHOULDER EYEBOLT SEE TEXT EYEBOLT SUPPLIED WITH PULL UP STRAP 14 5 MAX Figure 15 ElectroVoice 600 Cecil Street Buchanan M
5. I 49107 800 234 6831 616 695 6831 616 695 1304 Fax OTelex Communications Inc 1998 Litho in U S A Part Number 534762 9822
6. ON TI o pL Figure 6 60 EVI SYSTEM MOUNTED HEIGHT AND T 20 8 8 AIMING ANGLE a E 110 Direct Field SPL C50 t ide Figure 7 EVI SYSTEM MOUNTED AT 18 HEIGHT AND 10 AIMING ANGLE EVI SYSTEM MOUNTED AT 22 HEIGHT AND 10 AIMING ANGLE Direct Field SPL E p EERE HEEE C50 Ej E e E E Er 10 Figure 8 EVI SYSTEM MOUNTED BACK TO BACK AT 30 HEIGHT AND 5 AIMING ANGLE Direct Field SPL Figure 9 EVI SYSTEM MOUNTED HEIGHT AND AIMING ANG AT 25 15 Direct Field SPL AAA ng i Se ee oe oe Oe A eee a N I DEDOS EJ EISE ES Se LR e RET ERASERS AR E AUN dB Ob O E aaa AAA E De See ee See SRS Seen EDES MEMES T SM ERES O A Eee eo mH L noo oe eee BS i Sea ven Eene veendam za kade Ne NES MEME Oban Be Be eee Et ee eee et EME dl N Ct OPES MN E M Ge rc p H em menu coi ud Lopepeseser sr Fale Hz EN dl ee MENTES SaaS leeks fii ook Sees eee en No NS EX SE EH EN 3388 ab Di a HE SE ME HHEHUEIHEEHEEES HH HHEHHIHHBHE EASTER OE lo ee Gelb eed ee Bisse LI EIE p RE Eoo psum n Ln bn o n Ln n Ln Ln eoe Gi Lo e PD llo mS MTO C50 Da E Saomondma 12 Figure 10 240 2 EVI SYSTEM MOUNTED E m H E m o it E
7. by at least 15 more than sufficient for nearly any application see Figure 15 The brackets are sup plied with friction washers that will prevent the en closure from rotating over time but to be abso lutely certain the installer should use a set screw in the threaded hole to fix the enclosure permanently in position The described hanging methods are rated for suspending only one speaker with a minimum of an 8 1 safety factor Hanging any additional weight from the speaker will exceed its strength rating and create an unsafe condition A Sampling of EVI Applications Now that the technical details are covered here are a few ideas on applications that the EVI systems will cover with far more uniform sound and lower overall cost than any conventional enclosure The first and most obvious application is in a church or some other well defined space that has a fairly tall ceiling and proportions of roughly 2 x 3 see Figure 1 In this application the EVI systems can easily replace a central cluster or distributed sys tem with a single low cost enclosure and still main tain a more uniform sound distribution Figure 2 shows a similar room but with a somewhat longer throw where the EVI systems also perform very well Many auditoriums and theatres are much wider than a typical set of church pews so Figure 6 shows a fairly standard auditorium floor plan and possible mounting locations Any interference between the systems will be co
8. com passed the same 36 foot width but at least 64 feet in length an additional 10 feet of extension Of course the front row position has moved back about 5 feet with the change in angle as shown but this is easy to account for when initially positioning the system and is exactly what happens if you take a conventional system and change the angle For rooms that are closer to square tilting the loud speaker system down by 15 provides a very clean square pattern In this case the offset to the first row 1s about 0 25 times the height of the system For example a tall square room 1s about 60 feet wide and only 65 feet long Tilting the enclosure down by 15 at a 30 foot mounting height makes a 60 foot wide by 60 foot long pattern The offset to the first row is 0 25 multiplied by the 30 foot height or about 7 5 feet forward from the back of the en closure Minor adjustments in aiming will make the SPL fill the room very evenly with no loss in tonality in the corners and high overall intelligibility By contrast a typical two way system witha 60 x 40 CD horn in the same mounting location as Figures and 2 see Figure 3 produced a floor plan that sounded tonally fairly consistent with a 20 to 24 foot width and 30 foot depth with an offset of nine feet to the front row On paper this seems like adequate performance but in the room it has very noticeable 6 dB or greater variation 1n overall level from side to center and
9. en long and short throw horns We ve also elimi nated the cost of a properly designed two horn system which must include another power am plifier channel for good power control and impedance matching Labor savings in the box With structural rigging from the factory these systems will fly more conveniently and in less time than many competitive products In addi tion less time is spent on the aiming and repo sitioning that is required with traditional long throw short throw horn combinations This will save you additional money Installation procedures for any conventional loudspeaker are fairly well defined and easy to un derstand find an appropriate hanging height and position that affords a clear path to the listening area such as above the center of a stage or above the lectern in a church and aim the loudspeaker to wards the center or just to the rear of center of the room With this method you hope to cover the majority of the room with fairly consistent sound but the mid and high frequencies never seem to fill perfectly Itis frequently aimed a little too far back and there is a large amount of slap echo or the front row 1s too loud the back row too soft and the front and back row corners sound muted due to a lack of high frequency energy Other solutions to filling the room have been suggested and imple mented including a dual horn format one long throw and one short throw This method works fairly well but e
10. gree EASE By comparing the 2 5 and 10 resolution you can eas ily see the apparent loss in direct field SPL This loss shows up as a series of steps along the length of the room and an artificially narrowed throw with less SPL in the corners than would be achieved in a real world installation Please keep this in mind when using simulation software Hanging EVI Systems For the EVI 12 and EVI 15 the physical mounting of the systems have been designed to be as easy as possible with two simple options avail able By far the easiest solution is to use the op tional sturdy cost effective EVI 12MB or EVI 15MB U Brackets that mount to the 3 8 16 T nut locations on the sides of the enclosure The sup plied forged shoulder eyebolt must be used in the t nut location on the lower back side of the system as a pull up point see figure 13 With this arrangement the U Bracket holds approximately 80 of the weight of the system and the pull up point pro vides a convenient method of adjusting the aiming angle The U Brackets have easy to install bolt patterns and include three sets of OmniMount 100 bolt patterns For most applications this will be the preferred methodology as itis fast aesthetically pleasing flexible and inexpensive However this method will not work in all applications so we have included a second set of T nut locations on the top of the enclosure so that the hanging cables can be completely out of view from bel
11. in some aiming cases over 10 dB of variation from front to back as well as a pronounced lemon shape The sides of the first three to five rows in a church and the last few rows were noticeably muted and much lower in overall level As mentioned before a two horn system can work fairly well but the physical offsets required for installation inevitably result in some amount of destructive interference throughout the room see Figure 4 Figure 4 was produced using a 90 x 40 CD horn aimed down by 65 and a 60 x 40 horn aimed down by 30 The actual physical offsets were used to simulate the floor response in direct field SPL The displayed figure agrees very well with the measured response show ing a 14 dB variation at 4kHz in a distance of 3 feet horizontally Tonal changes as a result of interfer ence pattern change versus frequency were clearly audible in an acoustically well behaved room but were overall much less audible than for a single sys tem with aconventional CD horn Locating drivers and horns closer together than possible with me dium format horns will produce somewhat better results but will always result in fairly severe lobing Polar measurements in 2 increments show the lobing very well but the smoothing required for trans lation to the EASE 10 resolution database will elimi nate the vast majority of peaks and dips resulting in what appears to be a fairly smooth simulation In contrast the new VI systems
12. lligi bility and even SPL throughout the listening area Q vs Intelligibility The Q of a system is a good measure of the system s directivity and in some ways a good mea sure of whether the system s in room response will be consistent across the frequency range A typi cal 12 inch two way system with a 60 x 40 horn will maintain a fairly constant Q from 16 30 or 12 15 dB normally about 26 or 14dB from 3 000 20 000 Hz and a 90 x 40 a Q of 13 15 11 12dB Very high directivity horns such as a 40 x 20 will have an average Q in the range of 45 16 5 dB and very low directivity horns like a 120 x 40 will have a Q of 7 9 8 5 9 5 dB It is generally thought that a high directivity horn will have greater intelligibility across a given pattern area than a lower Q device and this 1s true 1n most cases Also true in most cases is that a standard horn pat tern will not fill a typical floorplan thus drastically reducing the effectiveness of the higher Q In direct comparison the VI horn pattern will fill a majority of floorplans with direct field sound rather than re lying on reverberant energy to fill in the gaps in overall sound quality and quantity The Q of the VI systems are very consistent from 1 000 20 000 Hz with a range of 10 18 10 12 5 dB and an aver age Q of 13 5 11 5dB or consistent with the overall directivity of a 90 x 40 system This might lead you to believe that the VI systems are low Q
13. loor pattern does not fit the VI horn exactly then it cannot be used at all This is not the case and 1f it were the case we could not use standard constant directivity horns in most applications either The larger VI systems have an optimum room that is approximately twice the height in width and three times the height in length This 1s the ideal condi tion but the figures and descriptions that follow should give you a good feel for the wide range ca pabilities of the systems EVI 12 and EVI 15 Installation The nominal floorplan that the system will cover with equal SPL is approximately two units wide by three units long where the height of the loudspeaker defines the size of the unit For ex ample if the loudspeaker is 18 feet above the floor it will typically cover a floorplan of about 36 feet wide by 54 feet long In this typical installation see Fig ure 1 the back panel of the loudspeaker is mounted approximately 0 6 units about 11 feet back from the first row and has a nominal angle of the top of the enclosure parallel to the floor or slightly tilted back 2 to 3 degrees For rooms that are much longer than normal the VI systems are very easy to aim and position to fill the entire length Experi ments in actual listening rooms have shown that with the same mounting height of 18 feet but with the front of the enclosure tilted up by approximately 10 see Figure 2 the total floorplan now en
14. m causing interference patterns 1n the listening area Since an EVI 28 has a very smooth and rapid drop off towards directly below the cabinet you can actually stand right in front of the speaker see Figure 12 without ear strain or heavy microphone feedback The remark able absence of lobes to the rear allows the system to be mounted directly overhead to target a par ticular area without disturbing the audience below or behind the cabinet For example FIGURE 11 shows a typical under balcony application that has a floor with an upward slope of 5 The speaker is mounted 10 feet above the seated head height so the horizontal width is fixed at approximately 20 feet The enclosure is tilted back by 5 to provide a 50 foot throw with the outskirts of the pattern filling in the rear aisle area with tonally accurate but reduced overall SPL If the under balcony seating area is only 35 feet deep then the enclosure should be tilted down by about 10 relative to the floor in order to prevent excess slap echo and preserve intelligibility Figure 12 shows a typical small room application perfect for a 20 foot by 30 foot boardroom or meeting hall In this case the head height is actually defined by a standing height of approximately 6 feet so the long throw axis should be very close to hori zontal Then the included 40 degree angle points directly towards the entire listening area minimizing slap echo while retaining a full width high inte
15. ncentrated in the center aisle where sound quality is not as critical The EVI 12 EVI 15 and EVI 28 systems are also ideal for re placing distributed arrays providing much more uniform coverage at a lower cost See Figure 7 for an idea on how the same auditorium floor plan could be easily covered in a surround style arrangement with just two EVI systems per side rather than four distributed arrays Although not providing the high est intelligibility or smoothest response itis appli cable to cinemas and some musical preferences This has the advantages of cutting installation time amplifier channels additional delay lines and at the same time providing superior coverage A gymnasium is another perfect application for the EVI systems covering each grandstand from a pair of centrally located EVI systems see Figure 8 In addition you can cover the entire gymna sium from either a single lengthwise oriented sys tem or with a pair of widthwise spaced systems with lower SPL coverage on the floor of the gymnasium than in the stands so the players are not disturbed by announcements see Figure 9 When the EVI 12 and EVI 15 systems are tilted up approximately 15 their coverage pattern lengthens to match a level EVI 28 at 5 times the height In such cases the systems work very well to replace a distributed system along a very long fairly wide corridor where very high SPLs are not required on a continuous basis such as an airport c
16. ncounters several problems the added expense of another horn driver combination the vastly increased time to physically install and then tune the level and aiming of two horns the 1n evitable destructive interference patterns through out the listening area the expense of another ampli fier channel to achieve correct impedance match ing and the need for a very aesthetically clean in stallation with no odd looking to the customer dangling horns Another solution is to have a horn that is variable angle in order to throw a narrow pattern to the back of the room The problem with this concept is that this doesn t take into account the drop in SPL between the near throw about 25 feet and the far throw about 70 feet so the high frequencies are about 10 dB down in the back of the room To solve all of these problems the Vari In tense horns were invented yet another innovation in the long tradition of Electro Voice When properly aimed the Vari Intense horns can provide extremely even SPL throughout an entire room filling in the corners without pushing too much energy at the back wall thus avoiding slap echo The rules of fixed installation have just changed The Electro Voice EVI 12 EVI 15 and EVI 28 enclosures are the first in a new generation of problem solving systems The new systems are designed as a package with easy mounting refin ishing ability lightweight compact and unobtrusive size and shape and the clas
17. oncourse with 15 to 20 foot ceilings where a speaker would be placed about every 75 feet See Figure 10 for approximate mounting locations and floorplan coverage These are but a few of the widely varied applications where the new EVI 12 EVI 15 and EVI 28 systems will easily outperform a conven tional system The extremely uniform coverage of the systems are fairly insensitive to placement re quire only afew simple calculations to find the best mounting location and the aiming angle is no more or less sensitive than a conventional loudspeaker This makes installation nearly foolproof Even installation in non optimal conditions will produce remarkably even coverage and high intelligibility As questions arise you may feel free to con tact us at 800 234 6831 or FAX at 616 695 1304 NOTE All figures are direct field SPL and C50 produced in EASE with interference turned on when applicable All plots depict the intended listening areas only and do not include the offset distance to the first row For example the first set of plots on figure 3 depict the same 54 x 36 area as figure 1 See notes on simulation software Figure EVI SYSTEM MOUNTED AT 18 HEIGHT AND 0 AIMING ANGLE TOP PARALLEL TO FLOOR Direct Field SPL C50 Figure 2 EVI SYSTEM Direct Field SPL D Direct Field SPL C50 Figure4 Direct Field SPL Vertical Polar e ER
18. ow see Figure 14 The front pair of hanging points should carry ap proximately 50 Ibs of the enclosure s weight with the required pull up point taking the balance of the weight about 5 Ib The T nut locations are intended to be used only with forged shoulder eyebolts with a minimum tensile strength of 350 kg 770 Ib The inexpensive EBK 1 kit includes three eyebolts especially helpful when access to quality forged shoulder eyebolts is limited Please keep in mind that the center of gravity is designed to be behind the main hanging points This means that the back of the system will rotate as much as 50 degrees down allowing easy aiming adjustment to virtually any angle Please note the pull up location on the lower section of the back panel of the enclosure MUST be used to hang the system in order to provide a safe stable mounting system The pull up point pro vides an additive safety as itis capable of holding the speaker system with a safety factor of at least 5 1 in the unlikely event of a failure in the main load bearing system For the EVI 28 the mounting holes are posi tioned very near the center of gravity for easy aim ing The U brackets may be rotated all the way around the back of the enclosure allowing easy 1n stallation and aiming The maximum vertical angle that may be reached is approximately 35 less if the loudspeaker is mounted flush against a ceiling In this case the enclosure may be rotated upwards
19. sic musical sound that Electro Voice is known for The new small format VI horn maintains consistent directional control down to 2 000 Hz Inthe EVI 12 and EVI 15 the VI horn 1s optimally crossed over to an specially angled woofer Note the 12 1n driver in the EVI 121s at a different angle than the 15 1n driver in the EVI 15 optimizing the floor pattern with the differ ing directivities of the two drivers In the EVI 28 the VI horn is crossed over to a pair of vertically arrayed 8 inch woofers with a proprietary technique that provides delay amplitude and frequency shad ing to the two woofers The EVI 12 EVI 15 and EVI 28 systems are installed just like any conventional loudspeaker keeping in mind a few simple guidelines Let me preface these guidelines with a simple but impor tant comment the VI systems are extremely versa tile and will work in a large variety of applications They will work well with tall ceilings short ceilings rectangular rooms slightly trapezoidal rooms and a whole host of odd shapes so long as the coverage area 1s fairly close to rectangular The larger EVI 12 and EVI 15 have been tested in rooms with 12 foot ceilings and performed very well although with reduced width of throw A single EVI 12 was installed in a room 75 foot by 150 foot and an average RT60 of 4 5 in the mid band and performed very well with good intelligibility and a minimum of slap echo It has been thought in the past that if the f
20. ugh the crossover point This extends the VI characteristic down to 500 Hz in an extremely compact enclosure The high frequency horn in the EVI 28 is mounted tilted 15 back relative to the EVI 12 and EVI 15 Along with the polar steering in the woofer s crossover this arranges the dispersion for long throws relative to the mounting height The recommended operational vertical angle is minus 5 from the top surface of the enclosure to minus 45 defining a maximum used vertical dispersion of 40 The standard aiming of the system when it is mounted above a flat floor 1s with the top of the enclosure parallel to the floor In this orientation the system will provide even SPL over a floorplan that is approximately twice as wide as the mounting height and five times as long Tilting the enclosure down by approximately 10 to 15 relative to the slope of the floor will produce a floorplan the same as an EVI 12 or EVI 15 At the standard aiming the 45 nearfield operational angle defines an ap proximate offset to the first useable row of one half the height of the speaker system above the listening plane In a typical installation the top surface of the loud speaker will point slightly above the head height of the furthest targeted seating or standing area This will ensure the minimum amount of slap echo from the back wall In an under balcony situation the sharp cutoff above the zero degree axis prevents early ceiling reflections fro
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