Electro-Voice MTL-4B User's Manual
Contents
1. 4B may be combined with other members of the MT 4B and MT 2B loudspeaker family providing the array designer a variety of coverage angles acoustic output and enclosure sizes from which to choose For full range applications the MTL 4B may be combined with the MTH 4B or MTH 2B midbass mid frequency high frequency loudspeaker systems The MTH 4 64B and MTH 4 42B systems have rectangular enclo sures that are dimensionally identical to the MTL 4B For maximum acoustic performance of the MT loudspeaker systems the Electro Voice Dx34 digital electronic crossover equal ization time delay imiter unit is recommended Careful attention was paid to details to provide both the touring company and sound contractor a convenient and timesaving sound reinforce ment package The MT 4B dimensions were chosen for efficient truck pack and high density array design The systems may be stacked three high and three wide in a standard truck box enabling 14 000 watts of sound system to be accommodated in only three feet of truck floor length The two point rigging system of fers flexible array design and efficient assem bly To facilitate service a variety of screws washers and hex key wrenches are provided with each loudspeaker system In addition there are wiring diagram labels in convenient locations inside the enclosure FREQUENCY RESPONSE The MTL 4B frequency response shown in Figure 1 was measured both with and without equalization a2. for even coverage In these instances it may be possible to regain much of the effi ciency lost removing the low frequency sys tems from the floor by closely spacing the systems to increase the mutual coupling and by constructing the low frequency array in a manner that increases the low frequency direc tivity CROSSOVER EQ AND TIME DELAY The usable frequency range of the MTL 4B low frequency loudspeaker system is 32 200 Hz A crossover frequency of 160 Hz with 24 dB per octave slopes is recommended For full range applications one of the MTH 4B midbass mid frequency high frequency loudspeaker systems iS recommended for use with the MTL 4B For optimal acoustic performance the Electro Voice Dx34 digital electronic crossover equalization time delay unit is recommended The Dx34 is a programmable two in four out digital electronic unit which may be configured SPL In dB n m u 158 J Ww 1 pen s i eee FREQUENCY IN HERTZ FIGURE 2 Impedance vs Frequency 31 6 S TT rm r 10 LFI ALF PARALLELED I a az fh 16 r i Y R m lal x 2 mes al HH Mad IMPEDANCE i i FREQUENCY IN HERTZ FIGURE 3 Polar Response 5 dB PER DIVISION HORIZONTAL FIGURE 4 Beamwidth vs Frequency 360 y 300 BEAMWIDTH IN DEGREES GdB FREQUENCY IN HERT VERTICAL DIRECTIVITY INI FREQUENCY IN HERTZ FIGURE 6 Harmonic Distortion INI n
3. not apply to burned voice coils or malfunctions such as cone and or coil damage resulting from improperly designed enclosures Electro Voice active electronics as sociated with the speaker systems are quaran teed for three 3 years from the date of Original purchase Additional details are included in the Uniform Limited Warranty statement Electro Voice Flying Hardware including en closure mounted hardware and rigging accesso nes is guaranteed against malfunction due to defects in materials or workmanship for a period ofone 1 year from the date of original purchase Additional details are included in the Uniform Limited Warranty statement Electro Voice Accessories are guaranteed against malfunction due to defects in materials or workmanship for a period of one 1 yeartrom the date of original purchase Additional details are included in the Uniform Limited Warranty state ment Service and repair address for this product Electro Voice Inc 600 Cecil Street Buchanan Michigan 49107 616 695 6831 or 800 234 6831 Specifications subject to change without notice ELECTRO VOICE a MARK IV company 600 Cecil Street Buchanan Michigan 491 07 NEWPORT TN m SEVIERVILLE TN m OKLAHOMA CITY OK M GANANOQUE ONT Part Number 532447 9502
4. the manifold chamber during instantaneous power peaks All versions of the MTL 4B are constructed of 0 75 inch thick 14 ply birch plywood and ex ae b ES SM Oq AN A A QF DI A d RI BET A e da step Ht Ba A ea A E a SR BRETT ea sak FEIN o tremely well braced to survive the rigors of the road The MTL 4BCF flying and MTL 4BC non flying systems are covered with black Ozite Super TNT carpeting the most rugged in the industry For permanent installation appli cations the MTL 4BPF flying and MTL 4BP non flying systems are available with a black textured paint finish The MTL 4BCF carpeted and MTL 4BPF painted systems incorporate a unique two point flying system All models feature a black nylon cloth grille The RD 1 removable dolly is available for use with the carpeted MTL 4BCF and MTL 4BC versions for portable applications APPLICATIONS The MTL 4B is ideal for any professional con cert sound touring or permanent installation application requiring high sound pressure lev els atlow frequencies with low distortion from a compact enclosure The Manifold Technology design maximizes the acoustic output per en closure frontal area acoustic output per enclo sure bulk volume and acoustic output per enclosure weight of the loudspeaker system This enables loudspeaker arrays to be con structed that are significantly smaller and lighter than would be obtainable with conventional loudspeaker system designs The MTL
5. Electro Voice SPECIFICATIONS Frequency Response measured in farfield calculated to one meter on axis swept one third octave pink noise one watt input anechoic environment see Figure 1 37 200 Hz Low Frequency 3 4B Down Point 42 Hz Usable Low Frequency Limit 10 dB down point 34 Hz Half Space Reference Efficiency 11 3 Long Term Average Power Handling Capacity per ANSI EIA 426 A 1980 see Power Handling Section 1 600 watts Maximum Long Term Average Midband Acoustic Output 181 watts Sensitivity SPL at one meter indicated input power anechoic environment band limited pink noise signal 1 Watt 101 5 dB 1 600 Watts 133 5 dB Beamwidth angle included by 6 dB down points on polar responses indicated one third octave bands of pink noise 80 160 Hz horizontal and vertical see Figures 3 and 4 177 37 Directivity Factor R Q 80 to 160 Hz Median see Figure 5 2 84 0 42 0 37 Directivity Index D 80 to 160 Hz Median see Figure 5 4 5 dB 0 6 dB 0 6 dB Distortion 0 1 Full Power Input see Figure 6 Second Harmonic 50 Hz 1 7 100 Hz 0 5 Third Harmonic 50 Hz 1 6 100 Hz 0 2 Transducer Complement Four DL18MT Box Tuning Frequency 37 Hz Impedance LF1 and LF2 paralleled see Figures 2 7 Nominal 2 0 ohms Minimum 2 0 ohms Input Connections Neutrik Speakon NL4MPR Enclosure Materials Structural All Versions 14 ply birch plywood Fini
6. e half the beamwidth of a single system in the plane that they are arrayed Adding additional systems will reduce the beamwidth further at low fre quencies Systems can be arrayed both hori zontally and vertically to increase directionality in both planes LOUDSPEAKER LOCATION Low frequency loudspeaker systems such as the MTL 4B are often located on the floor or close to walls This is often convenient and provides additional acoustic loading to increase the low frequency efficiency of the system Because there s typically little directional infor mation present in program material below 125 Hz the audible location of the low frequency loudspeaker systems will not be particularly evident with those systems located on the floor separated from the higher frequency systems positioned overhead for the desired locational cues and uniform audience coverage Other situations however may benefit from having the low frequency systems suspended overhead along with the higher frequency sys tems Floor space may be limited or sightlines may be a problem on the main floor seating area requiring low frequency systems to be suspended overhead higher crossover fre quencies or program material with low frequency locational cues may require the low frequency systems to be located near the higher fre quency systems or a particular geometric lay out of a venue and sound system may require low frequency systems to be suspended over head
7. e the back plate which can result in damage to the speakers Even if bottoming does not occur the subpassband signals waste amplifier power cause undue mechanical stress on the speakers and result in high levels of loudspeaker distortion USE IN MULTIPLES MTL 4B systems may be used in multiples to increase acoustic output When two loudspeaker systems are placed side by side a 6 dB in crease in maximum acoustic output power is possible at low frequencies assuming all woof ers are operating with the same polarity This increase occurs because at low frequencies the woofer cones from the two systems mutu ally couple acting as a single cone with twice the area and therefore twice the efficiency providing a 3 dB increase in sound pressure level The second 3 dB comes from the dou bling of the power capacity by adding a second system Mutual coupling occurs when the cen ter to center spacing between the two loud speaker systems is approximately one half wavelengthorless When the spacingis greater than one half wavelength as would occur if two systems were widely spaced the maximum acoustic power output increase is limited to the 3 dB power handling increase Additional sound pressure level can also occur from the increased directivity that results when multiple systems are closely arrayed together If two systems are placed side by side the beamwidth of the combined systems al low frequencies will be approximately on
8. h i DIRECTIVITY FACT 10054111 90 tt I i k ka 7777 gt ul 70 60 H 50 11 Ll _ Li u KH 2nd HARMONIC 3rd HARMONIC 40 11 E rn n 159 me Lid K Tun kur FREQUENCY IN HERTZ FIGURE 7 Wiring Diagram WHITE WHITE 2 _ _ _ ____ LF2 4 OHMS MOM Ane 3 0 OHMS 2 Oo _ BLUE Sie tag D RED T ss E AA AAA LF1 4 OHMS NOM Roc 3 0 OHMS E BA 2 BLACK 1 TERMINAL IS RED TERMINAL IS BLACK for stereo two way mono three way plus sub woofer or mono four way operation Each out put section includes crossover filters equaliza tion limiting time delay polarity and gain ad section nas equalization specitically matched to the loudspeaker system and time delay set to achieve zero lobing error and time alignment between frequency bands In addition the out put levels of each frequency band are set so that with the output level controls set in the zero dB position the loudspeaker system will have a flat frequency response in an anechoic envi ronment when used with amplifiers having iden tical gain ELECTRICAL CONNECTION AND SYSTEM WIRING Electrical connections to the MTL 4B are made on the back of the enclosure viaa 4 pin connec tor There are two connectors on the input panel to allow paralleling of other MTL 4B systems The Neutrik Speakon NL4MPR is
9. ll up points are usu ally unnecessary Furthermore all of the flying EY MANUFACTURING PLANTS AT E BUCHANAN MI m Electro Voice Inc 1995 mg Litho in U S A MT 4B and MT 2B loudspeaker models include the same rigging hardware allowing the differ ent models to be mixed as necessary through out an array the enclosure or on the top and bottom and may be daisy chained together as long as the safety factor is 5 1 or greater and local regula tons are met Electro Voice offers a line of flying hardware accessories for use with the MT loudspeaker systems CAUTION The MT loudspeaker systems should be suspended overhead only in ac cordance with the procedures and limita tions specified in the MT Flying Manual and manual update notices FIELD SERVICE In the unlikely event that the MTL 48 should require service the 18 inch woofers can be accessed from the front of the enclosure by removing the grille using a 42 Phillips screw driver The woofers can be unbolted using a 9 32 inch hex key wrench and slid straight out of the manifold chamber There is a wiring diagram label for the system located on the underside of the input panel As a further ser vice Convenience a hardware kit that includes a 5 32 inch hex key and an assortment of spare screws and washers are included with every MTL 4B loudspeaker system A woofer failure will require the entire driver to be returned to an authorized Electro Voice service center f
10. mbination of the MTL 4B loudspeaker system and the MTH 4B midbass mid frequency high frequency loudspeaker systems form the MT 4B full range system There are four models in the MTL 4B series the MTL 4BCF carpeted finish with flying hardware the MTL 4BC carpeted finish without flying hardware the MTL 4BPF painted finish with flying hardware and the MTL 4BP painted finish without flying hardware The MTL 4B is a vented box design comprised of four DL18MT 18 inch woofers each facing into a manifold chamber at the center of the enclosure This manifolding technique U S Patent No 4 733 749 results in increased acoustic loading yielding increased low fre quency efficiency and reduced distortion over conventional direct radiating designs in a re markably small enclosure The MTL 4B is typi cally 2 3 dB more efficient than horn loaded enclosures of equivalent size in the 40 80 Hz range Additionally by having the motor struc ture on the outside of the enclosure this radical design allows for efficient heat transfer from the loudspeakers to minimize thermal build up dur ing extended periods of high power operation The DL18MT 18 inch woofer was designed specifically for manifolding to achieve optimal performance in the MTL 4B enclosure Its long voice coil design assures linear low distortion output at high power levels while its robust mechanical design is capable of withstanding the high acoustic pressures developed in
11. nd crossover filters on axis in the tarfield in an anechoic environment using a swept sine wave signal When measured with an electronics the Dx34 digital electronic unit was used to provide the necessary crossover filters and equalization With the crossover in place a high pass protection filter was applied to the low end of the low frequency section One watt of power 1 414 volts rms at 70 Hz was applied to the midband of the low fre quency section The sound pressure level was normalized for an equivalent one meter dis tance DIRECTIVITY The directional response of the MTL 4B was measured in an anechoic environment at a distance of 6 1 meters 20 feet using 1 3 octave filtered pink noise A full spherical mea surement system was used The polar response of the loudspeaker system at selected 1 3 octave frequencies is shown in Figure 3 The frequencies selected are fully representative of the polar response of the system The beamwidth of the system utilizing the complete 1 3 octave polar data is shown in Figure 4 The Directivity Factor Q R and Directivity Index D are shown in Figure 5 Complete AcoustaCADD data is available for the MTL 4B loudspeaker system DISTORTION Distortion for the MTL 4B shown in Figure 6 was measured on axis in the farfield in an anechoic environment ata level of 0 1 times the full power rating 160 watts as per the AES standard The sound pressure level was nor malized for an equi
12. or repair The following parts are available from the Electro Voice Service Department in Buchanan Michigan MTL 4B Service Data Sheet 532486 LF 818 882 DL18MT Driver ARCHITECTS AND ENGINEERS SPECIFICATIONS The loudspeaker system shall be a low fre quency system and shall operate from 37 200 Hz with a sensitivity of 101 5 dB for one watt at one meter The system shall consist of four 18 inch woofers manifolded at the center of a vented box enclosure have a total input im pedance of 2 ohms and have a power rating of 1 600 watts as per ANSI EIA 426 A The loud speaker system shall have an enclosure con structed from 0 75 inch thick 14 ply birch ply wood be finished with a black carpet ora black textured paint have a black nylon grille and have a two point rigging system that will accept Kinedyne 32102 1 of 32111 1 type double stud ring fittings if applicable The loudspeaker enclosure shall be 36 00 inches high 36 00 inches wide and 29 88 inches deep and weigh 263 pounds The loudspeaker system shall be the Electro Voice MTL 4B MTL 4BCF MTL 4BC MTL 4BPF or MTL 4BP UNIFORM LIMITED WARRANTY Electro Voice products are guaranteed against malfunction due to defects in materials or work mansh n for a snecifiac nodad amnagta m A or in the individual product data sheet or owner s manual c malfunction resulting from use or operation of the product other than as specified in the product data sheet or owne
13. rs manual d malfunction resulting from misuse or abuse of the product or e malfunction occurring at any time after repairs have been made to the product by anyone other than Electro Voice or any of its authorized service representatives Obtaining Warranty Service To obtain warranty service a customer must deliver the product prepaid to Electro Voice or any of its authorized service representatives together with proof of purchase of the product in the form of a bill of sale or receipted invoice A list of authorized service representatives is available from Electro Voice at 600 Cecil Street Buchanan MI 49107 616 695 6831 or 800 234 6831 Incidental and Conse quential Damages Excluded Product repair or replacement and return to the customer are the only remedies provided to the customer Electro Voice shall not be liable for any incidental or consequential damages including without limita tion injury to persons or property or loss of use Some states do not allow the exclusion or limita lion of incidental or consequential damages so the above limitation or exclusion may not apply to you Other Rights This warranty gives you specific legal rights and you may also have other rights which vary from state to state Electro Voice Speakers and Speaker Systems are guaranteed against malfunction due to de fects in materials or workmanship for a period of five 5 years from the date of original purchase The Limited Warranty does
14. sh MTL 4AC MTL 4ACF Black carpet MTL 4AP MTL 4APF Black textured paint Hanging MTL 4ACF and MTL 4APF only Two point flying system tracks accept Kinedyne 32102 1 and 32111 1 fittings Dimensions Height 91 4 cm 36 00 in Width 91 4 cm 36 00 in Depth 75 9 cm 29 88 in Net Weight 119 kg 263 Ib Shipping Weight 141 kg 311 Ib DESCRIPTION The Electro Voice MTL 4B low frequency loud speaker system is a member of the family of Manifold Technology MT loudspeaker sys tems designed for high level sound reinforce ment in concert sound touring and permanent installation applications The MTL 4B is a manifolded vented box low frequency system with a rectangular enclosure utilizing four high MTL 4B Manifold Technology Low Frequency Sound Reinforcement System DL18MT woofers for high impact reliable bass e Larger MT rectangular enclosure High acoustic output low distortion Manifold Technology enables smaller and lighter loudspeaker arrays MT systems with different coverage patterns and output capabilities may be mixed and matched e Unique rigging scheme for flexible array design and quick assembly e Available without rigging hardware Available carpeted or painted power 18 inch woofers This configuration re sults in remarkably high acoustic output from a small enciosure The MTL 4B may be com bined with other members of the MT 4B and MT 2B loudspeaker family The co
15. used for both connections One mating Neutrik Spea kon NL4FC cable end connector is supplied with each loudspeaker system The pin assign ments are as follows Pin 14 LF1 Pin 1 LF1 Pin 2 LF2 Pin 2 LF2 The MTL 4B has four 8 ohm woofers wired in paralleled pairs resulting in two nominal 4 ohm loads with one pair connected to Pins 1 1 and the other pair to Pins 2 2 A wiring dia gram of the loudspeaker system is shown in Figure 7 The electrical impedance versus fre quency is shown in Figure 2 FLYING THE MT SYSTEMS A manual entitled the MT Flying Manual is available from Electro Voice and is included with each flying MT loudspeaker system A brief introductory overview is included here The MT Flying Manual should be consulted for com plete structural specifications and detailed in formation on safely suspending and using the MT systems The MTL 4BCF carpeted and MTL 4BPF painted are versions of the MTL 4B loud Speaker system that include flying hardware The MT systems incorporate a unique two point flying system that permits a wide range of vertical angle adjustment and offers maximum flexibility in array design and implementation for both touring sound and permanent installa tions The quick release aircraft L track type hardware design allows arrays of loudspeakers to be assembled and disassembled very quickly and offers such flexibility in the vertical angling of cabinets that pu
16. valent one meter distance Plots of second and third harmonic distortion are shown referenced to the fundamental POWER HANDLING CAPACITY Electro Voice components and systems are manufactured to exacting standards to ensure reliability in continuous use in arduous real life conditions Besides utilizing industry standard power tests extreme in house power tests which push the performance boundaries of the loudspeakers are also performed for an extra measure of reliability The MT systems are rated as per the ANSI EIA 426 A Loudspeaker Power Rating Full Range Test which uses a shaped random noise signal to simulate typi cal music to test the mechanical and thermal capabilities of the loudspeakers Specifically the MTL 4B passes the ANSI EIA 426 A power test with the following test parameters LF Section LF1 amp LF2 paralleled oor 1 600 watts total Test Voltages 52 5 volts rms 105 volts peak Ron 1 15 x A 1 73 ohms SUBPASSBAND SPEAKER PROTECTION Below the enclosure tuning frequency cone excursion increases rapidly with little increase in acoustic output Itis therefore highly recom mended that a high pass filter be used to pro tect the system against subpassband signals A high pass filter 3 dB down at 32 Hz with a minimum slope of 12 dB per octave is sufficient to provide adequate protection for the MTL 4B Without protection subpassband signals may bottom the woofers i e cause the voice coils to strik
Download Pdf Manuals
Related Search