Electro-Voice MTH 2/94A User's Manual
Contents
1. Mark IV Vertriebs GmbH Larchenstrasse 99 6230 Frankfort Main 80 West Germany 49 69 380 100 Mark IV Audio Japan Ltd 2 5 60 Izumi Suginami ku Tokyo 168 Japan 81 3 325 7900 Electro Voice Pty Unit 24 Block C Slough Business Park Slough Ave Silverwater N S W 2141 Australia 61 2 648 3455 This warranty gives you spacific legal rights which may vary from state to state or province to province Service and repair address for this product Electro Voice Inc 600 Cecil St Buchanan 49107 Specifications subject to change without notice ELECTRO VOICE INC 600 Cecil Street Buchanan Michigan 49107 MANUFACTURING PLANTS AT W BUCHANAN BE NEWPORT TN W SEVIERVILLE TN OKLAHOMA CITY OK GANANOQUE ONT lectro Voice Inc 1991 Part Number 531761 1412. SHOWN WITHOUT GRILLE SPECIFICATIONS Frequency Response Measured in Farfield Calculated to One Meter on Axis Swept One Third Octave Pink Noise One Watt into MB Midband 2 83 V at 500 Hz Anechoic Environment see Figure 1 150 20 000 Hz Recommended Crossover Frequencies 160 Hz 1 600 Hz Efficiency MB HF 25 25 Long Term Average Power Handling Capacity per EIA Standard RS 426A see Power Handling section MB HF 600 150 watts Short Term Power Handling Capacity 10 milliseconds MB HF 2 400 600 watts Maximum Long Term Average Midband Acoustic Output 180 watts Sound Pressure Level at One Meter Indicated Input Power Anechoic Environment Band Limited Pink Noise Signal MB HF 1 1 Watt 106 110 dB 600 150 Watts 134 132 dB 2 400 600 Watts 140 138 dB Dispersion Angle Included by 6 dB Down Points on Polar Responses Indicated One Third Octave Bands of Pink Noise 400 20 000 Hz Horizontal see Figure 3 90 15 20 900 20 000 Hz Vertical see Figure 3 40 20 5 Directivity Factor R Q 600 20 000 Hz Median see Figure 4 17 9 3 0 dB 8 5 dB Directivity Index D 600 20 000 Hz Median see Figure 4 12 5 dB 1 2 dB 3 5 dB Distortion 120 dB SPL at 1 Meter Shaped Spectrum see Figure 6 Second Harmonic 200 Hz 1 3 1 000 Hz 1 6 3 000 Hz 6 3 10 000 Hz 4 9 Distortion 120 dB SPL at 1 meter Shaped Spectrum see Figure 6 Third Harmonic 200 Hz 0 4 1 000 Hz
3. 5 92 ohms EIA equivalent impedance 29 8 volts true rms Amplifier clipping sets instantane ous peaks at 6 dB above the continouous power or 600 watts peak 59 6 volts peak This procedure provides a rigorous test of both thermal and mechanical failure modes CROSSOVER EQ AND TIME DELAY The usable frequency ranges of the individ ual sections of the MTH 2 94A are 150 2 000 Hz for the midbass and 1 200 20 000 Hz for the high frequency band Minimum crossover slopes of 12 dB per octave are recom mended Low frequency protection capacitors are included in the high frequency section with a 3 dB down point of 800 Hz The usable frequency response of the overall MTH 2 94A midbass high frequency loud speaker system is 150 20 000 Hz For maximum performance of the MTH 2 94A a full range application the addition of the Electro Voice MTL 2A low frequency loud speaker system is recommended This combination forms the 2 94 full range high level sound reinforcement system For maximum acoustic performance use the Electro Voice XEQ 3 electronic crossover equalizer time delay unit with the EQMT2 plug in modules The XEQ 3 is a three way electronic crossover with adjustable crossover frequen cies utilizing Linkwitz Riley 24 dB per octave filters and time delay equalization to achieve zero lobing error In addition the XEQ 3 offers high pass filtering to protect woofers from infrasonic frequencies and frequency response equa
4. Inc 135 Kalamazoo Ave Kalamazoo MI 49007 Whirlwind Music Distributors Inc Box 1075 Rochester NY 14603 Neutrik USA Inc 195 S3 Lehigh Ave Lakewood NJ 08701 Both the midbass and high frequency inputs present a nominal 8 ohm load to the amplifier however the HF compression drivers have a low frequency protection capacitor in series The pin out arrangement is as follows Pin 2 HF Pin 2 HF Pin 1 MB Pin 1 MB HANGING The MTH 2 94A has been conceived to fly from the outset It incorporates EV s exclusive two point hanging hardware permitting a wide range of aiming angles and maximum flexibility The cabinet is reinforced and structurally sound allowing the MTL 2A and the 2 94 to be combined to form tight arrays The tracks are recessed to avoid box to box interference when flying and during transportation The track mates with the Kinedyne 32102 1 and 32111 1 double stud ting fittings Electro Voice offers a complete line of flying accessories for use with the MT 2A flying systems Ey CAUTION The MTH 2 94A speaker systems should be suspended overhead only in accordance with the procedures and limita tions specified in the Flying Manual included with the flying loudspeakers HORN ROTATION Place MTH 2 94A on a flat surface with horns facing up Remove grille by pulling black ribbons Remove all screws from around both the horn s mouths Lift the midbass horn a
5. 1 6 3 000 Hz 0 6 10 000 Hz 0 3 Transducer Complement MB Two DL10X 90 x 40 fiberglass horn HF Two 1 variant compression drivers HP94 variant 90 x 40 horn impedance Nominal MB HF 8 ohms 8 ohms Minimum MB HF 5 6 ohms 7 7 ohms Input Connections Two Neutrik Speakon NL4MPR Enclosure Materials 14 ply birch plywood Finish Black Ozite Super TNT carpet Hanging Two point flying system tracks accept Kinedyne 32102 1 and 32111 1 fittings Electro Voice o MARK IV company FIGURE 1 Axial Frequency Response using Recommended Crossover Equalization 1 Meter into MB Section MTH 2 94A Manifold MidBass High Frequency Sound Reinforcement System Dimensions Height 91 4 cm 36 0 in Width 57 2 cm 22 5 in Depth 76 2 cm 29 9 in Net Weight 97 kg 214 Ib Shipping Weight 102 kg 224 Ib DESCRIPTION The Electro Voice MTH 2 94A Manifold Technology midbass high frequency loudspeaker system is designed for the touring sound and permanent installation markets The 2 94 is a two way active horn loaded system with two drivers manifolded together in each frequency band There are four drivers contained within the 2 94 compact dimensions The combination of the MTH 2 94A midbass high frequency loudspeaker system and the MTL 2A low frequency loudspeaker system form the three way active MT 2 94A concert sound loudspe
6. aker system Optimum per formance of the MT 2 94A is obtained when used with the XEQ 3 electronic crossover equalizer time delay unit with the dedicated EQMT2 plug in modules The midbass frequencies 160 1 600 Hz are reproduced by two DL10X 10 inch drivers The drivers are loaded by Electro Voice s proprietary aperiodic phase plug U S Patent No 4 718 517 for extended upper end response The phase plug makes use of the fact that at higher frequencies only the apex area of the cone near the voice coil is in motion and automatically adjusts acoustic loading to maximize high frequency output The outputs of the two drivers are summed using Electro Voice s patented Manifold Technology U S Patent 4 923 031 and 6 dB BEAMWIOTH IN DEGREES BEAMWIDTH IN DEGREES FIGURE 3 MTH 2 94A Beamwidth vs Frequency DIRECTIVITY FACTOR Rg DIRECTIVITY INDEX D 98 FIGURE 4 MTH 2 94A Directivity Factor and Directivity Index vs Frequency Response composite of both orientations BELT T BEAT a NT A AAA ATT TT TASTY T W PU ALN FREQUENCY FIGURE 5 2 94 Axial Frequency Response using Recommended Crossover Equalization Time Delay and MTL 2 Low Frequency System T AA lt j pests beet a hb LEVEL IN dB FIGURE 6 MTH 2 94A Harmonic Distortion FIGURE 2 MTH 2 94A Polar Response 120 dB SPL 1 me
7. inet is covered in black Ozite Super TNT carpet the most rugged available A black nylon cloth grille is supplied as standard When an extended low end response is needed the MTH 2 94A can be used with the MTL 2A low frequency loudspeaker system APPLICATIONS The MTH 2 94A is designed with the profes sional end user in mind Whether used in regional touring or fixed installations the MTH 2 94A delivers versatile high level low distortion wide coverage performance The relative lightweight and smail volume of the MTH 2 94A belies the performance obtain able with Manifold Technology The compact dimensions allow the construction of very tight arrays Itis possible and often beneficial to use the MTH 2 94A as a stand alone device for example in pure speech reproduction However the MTL 2A low frequency loud speaker system has been designed to compliment the MTH 2 94A and produce a fully integrated full range sound system The cabinets are dimensionally identical and have matching hardware The dimensions of the MTH 2 94A were selected to allow efficient truck packing All fittings and fixtures are recessed to allow easy packing and unobtrusive installations The 90 x40 coverage pattern is independent of cabinet orientation The midbass and high frequency horns are mounted rom the front and are independent of their respective drivers see Horn Rotation section and are rotatable This means it is possible to u
8. ivity type horn The high frequency section shall have two 1 3 inch compression drivers each having a 16 ohm 3 0 inch diameter voice coil constructed of edge wound rectangular aluminum wire mounted on a 0 0015 inch thick titanium diaphragm and shall be capable of handling a 75 watt 1 000 10 000 Hz pink noise signal with a 6 dB crest factors for 2 hours as per AES2 1984 and ANSI 54 26 1984 standards These two drivers shall be manifolded onto a single 90 x 40 constant directivity type horn The loudspeaker system shall produce a horizontal beamwidth of 90 15 20 from 400 to 20 000 Hz and a vertical beamwidth of 40 20 5 from 900 to 20 000 Hz The loudspeaker system shall have a uniform on axis frequency response from 160 20 000 Hz when used with the Electro Voice XEQ 3 electronic crossover with crossover frequency at 1 600 Hz The overall system shall have an efficiency of 25 E Litho in U S A a MARK IV company The loudspeaker system shall have an enclosure constructed of 75 inch 14 ply birch plywood and shall have a black nylon grille The loudspeaker enclosure shall be rectangularly shaped Dimensions shall be 36 0 inches high 22 5 inches wide and 29 9 inches deep Weight shall be 214 Ib The loudspeaker system shall be the MTH 2 94A WARRANTY Limited Electro Voice MT Speakers and Speaker Systems excluding active electronics are guaranteed for five years from date of purchase against
9. lization in each frequency band through the use of plug in modules Optimum performance of the MTH 2 94A and MTL 2A loudspeaker systems is obtained when used with the XEQ 3 with crossover frequencies at 160 Hz and 1 600 Hz and with EQMT2 plug in modules a package of three EQ modules dedicated to the MT 2 94A system Information is included with the EQMT2 package detailing the front panel setting necessary to achieve the performance described in this data sheet CONNECTIONS Electrical connections are made on the back of the MTH 2 94A via 4 pin connector The midbass has two 8 ohm loudspeakers however the acoustic loading of the midbass phase plugs and horn increases their electrical impedance to 16 ohms each The two loudspeakers are wired in parallel resulting in an 8 ohm load accessed by two pins of the connector The high frequency section has two 16 ohm drivers wired in parallel resulting in an 8 ohm load accessed by the remaining two pins of the connector There are two connectors on the enclosure to allow paralleling of other MTH 2 94A systems The Neutrik Speakon NL4MPR_ panel mount connector is used for both connections One mating Neutrik Speakon NL4FC cable end connector is supplied with each system Neutrik Speakoncables connectors and wiring accessories are available from Pro Co Sound Inc and Whirlwind Music Distributors Inc To find your local Pro Co Whirlwind or Neutrik dealer contact Pro Sound
10. malfunction due to defects in workmanship and materials Electro Voice MT flying hardware rigging straps and enclosure mounted hardware is guaranteed for one year from date of original purchase against malfunction due to defects in workmanship and materials Electro Voice MT accessories including dollies are guaranteed for one year from date of original purchase against maifunction due to defects in workmanship and materials If such malfunction occurs unit will be repaired or replaced at our option without charge for materials or labor if delivered prepaid to the proper Electro Voice service facility Unit will be returned prepaid Warranty does not extend to finish appearance items burned coils or malfunction due to abuse or operation under other than specified conditions nor does it extend to incidental or consequential damages Some states do not allow the exclusion or limitation of incidental or consequential damages so the above exclusion may not apply to you Repair by other than Electro Voice or its authorized service agencies will void this guarantee A list of authorized service centers is available from Electro Voice Inc 600 Cecil St Buchanan 49107 616 695 6831 and Electro Voice West 8234 Doe Ave Visalia CA 93291 209 651 7777 Or Mark IV Audio Canada Inc 345 Herbert St Gananoque Ontario K7G2V1 Canada 613 382 2141 Mark IV Audio A G Keltenstrasse 5 CH 2563 Ipsach Switzerland 41 32 51 6833
11. nd rotate through 90 Lower horn back into cabinet Make sure the rear flange of the horn is seated correctly Repeat procedure with the high frequency horn Special care must be taken to locate and seal the rear flange into Electro Voice s new proprietary sealing gasket Replace all screws tighten down firmly but do not over tighten It is also possible to re orient the EV logo on the grille by removing the central screw rotating the logo and replacing the screw Replace the grille DRIVER ACCESS It is possible to access the high frequency compression drivers by removing the cabinet handles To access the midbass drivers it is necessary to remove the midbass horn and remove the manifold assembly Full details of these procedures can be found in the Service Data sheet available from the Service Depart ment in Buchanan Michigan ARCHITECTS AND ENGINEERS SPECIFICATIONS The loudspeaker system shall be a two way active midbass high frequency system with two drivers manifolded in each frequency band for a total of four drivers The midbass section shall have two 10 inch drivers each having an 8 ohm 2 5 inch diameter voice coil constructed of edge wound rectangular aluminum wire and shall be capable of handling a 300 watt shaped pink noise signal with 6 dB crest factor for 8 hours as per EIA RS 426 A standard These two drivers shall each be loaded on a phase plug and manifolded onto a single 90 x 40 constant direct
12. ne third octave bands Crossover equalization and time delay were set as recommended in the Crossover EQ and Time Delay section Beamwidths are illustrated in Figure 3 and directivity factors R Q and directivity indexes D in Figure 4 These figures show how smooth and controlled the 2 94 is over its entire operating range AcoustaCADD data is available for the 2 94 DISTORTION Using the recommended crossover equalization and time delay distortion for the MTH 2 94A was measured in the farfield with an input power that would result in a sound pressure level of 120 dB at one meter A frequency spectrum typical of contemporary close miked rock music was employed Plots of second and third order harmonic distortion are shown in Figure 6 POWER HANDLING CAPACITY To our knowledge Electro Voice was the first U S manufacturer to develop and publish a power test closely related to real life condi tions First we use a random noise input signal because it contains many frequencies simultaneously just like real voice or instrument program Second our signal contains more energy at extremely high and low frequencies than typical actual program adding an extra measure of reliability Third the test signal includes not only the overall long term average or continuous level which our ears interpret as loudness but also short duration peaks which are many times higher than the average just like act
13. se the 2 94 either horizontally or vertically without losing the desired coverage pattern itis strongly recommended that when the 2 94 is operated in isolation or with the MTL 2A that an XEQ 3 electronic crossover equalizer time delay unit be used The dedicated EQMT2 EQ modules should be used and the setup described in the Crossover EQ and Time Delay section followed FREQUENCY RESPONSE The 2 94 frequency response shown in Figure 1 was measured on axis in the farfield in an anechoic environment using a swept one third octave input and calculated to a one meter equivalent distance by using the inverse square law The MTH 2 94A system was set up using the XEQ 3 electronic cross over equalizer time delay unit and the EQMT2 plug in modules with the crossover frequency at 1 600 Hz and no crossover on the bottom of the midbass section One watt of power 2 83 V at 500 Hz was delivered to the midband of the midbass section The frequency response of the complete MT 2 94A system the MTH 2 94A and the MTL 2A together using the XEQ 3 with one watt 2 83 V at 500 Hz being delivered to the midbass section of the MTH 2 94A is shown in Figure 5 DIRECTIVITY Directional information is provided for both horn orientations Figure 2 illustrates the directional characteristics of the MTH 2 94A The measurements were taken in EV s large anechoic chamber at a distance of 20 feet using pink noise at selected o
14. ter using typical 4 octave 4 volts at 20 feet nominal music frequency spectrum fed directly into a new 90 40 fiberglass horn The horn provides a uniform coverage pattern with exceptional control and natural sound A special feature of the horn is that it is structurally independent of the drivers This makes it very easy to re orient the horn to suit prevailing circumstances see Horn Rotation section The higher frequencies 1 600 20 000 Hz are reproduced by two modified DH1A com pression drivers manifolded on the MTA 22 U S Patent No 4 629 029 and mounted on a special modified H94 90 x 40 constant directivity horn The HP series horn U S Patent No 4 685 532 features integral fiberglass and zinc construction which helps eliminate unwanted vibrations and allows the construction of beamwidth control vanes special waveguides in the horn throat that correct for very high frequency dispersion anomalies The HP94 is also structurally independent of its drivers allowing it to be easily removed and matched to the orientation of the midbass horn see Horn Rotation section The MTH 2 94A is designed to survive the rigors of the road 14 ply birch plywood is used throughout the external cabinet Electro Voice s unique two point flying system is installed as standard The Kinedyne quick release tracks are recessed below the surface to prevent damage and mechanical interference see Hanging section The cab
15. ual program The long term average level stresses the speaker thermally heat The instantaneous peaks test mechanical reliability cone and diaphragm excursion Note that the sine wave test signals sometimes used have a much less demand ing peak value relative to their average level In actual use long term average levels exist from several seconds on up but we apply the long term average for hours adding another extra measure of reliabilty Specifically the MTH 2 94A is designed to withstand the power test described in EIA Standard RS 426A The EIA test spectrum is applied for eight hours To obtain the spectrum the output of a white noise generator white noise is a particular type of random noise with equal energy per band width in Hz is fed to a shaping filter with 6 dB per octave slopes below 40 Hz and above 318 Hz When measured with the usual constant percentage analyzer one third octave this shaping filter produces a spectrum whose 3 dB down points are at 100 Hz and 1 200 Hz This shaped signal is then divided into the two frequency bands of operation using the recommended crossover equalization and time delay The midbass frequency amplifier was adjusted to deliver 600 watts into the 3 45 ohm ElA equivalent impedance 45 5 volts true rms Amplifier clipping sets instantaneous peaks at 6 dB above the continuous power or 2 400 watts peak 91 0 volts peak The high frequency was adjusted to deliver 150 watts into
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