ElectroVoice® MTH-2.5/42BT Manifold Technology® Mid-bass/High-Fre­ quency Sound Reinforce­ ment System • Sonically improved lower midrange • 40° x 20° constant-directivity pattern • Smaller MT trapezoidal enclosure • Rotatable MB & HF horns • 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 • Unique rigging scheme for flexible array design and quick assembly SHOWN WITHOUT GRILL • Available without rigging hardware SPECIFICATIONS Third Harmonic, MTH-2.5/42BT is an active, two-way, horn­ Frequency Response (measured in far 200 Hz: 0.8% loaded, 40° x 20° constant-directivity system field, calculated to one meter on axis, 1,000 Hz: 1.3% with a trapezoidal enclosure, utilizing two high­ swept sine wave, one watt into mid-bass 3,000 Hz: 0.1% power mid-bass drivers in the mid-bass fre­ section, anechoic environment; see 10,000 Hz: 1 .4% quency band and two high-power compression Figure 1): Transducer Complement, drivers in the high-frequency band . Both the 150-20,000 Hz MB: Two DL 1OX 10-inch drivers, mid-bass and high-frequency horns may be Recommended Crossover Frequencies: 40° x 40° fiberglass horn rotated in the enclosure. This configuration 160 Hz, 1,600 Hz HF: Two DH1A variant compression results in remarkably high acoustic output from Efficiency, MB/HF: drivers; HP42S, 40° x 20° horn a small enclosure. The MTH-2.5/42BT may be 16/25% Impedance (see Figures 2 & 7), combined with other members of the MT-2B Long-Term Average Power-Handling Nominal, MB/HF: and MT-4B loudspeaker family. The combina­ Capacity (per ANSI/EIA 426-A 1980; see 8/8 ohms tion of the MTH-2.5/42BT loudspeaker system Power Handling Section), Minimum, MB/HF: and the MTL-2B low-frequency loudspeaker MB/HF: 600/150 watts 4.917.2 ohms system form the MT-2/64B full-range system. Maximum Long-Term Average Mid-Band Input Connections: There are two models in the MTH-2.5/42BT Acoustic Output: Two Neutrik Speakon® NL4MP series: the MTH-2.5/42BTCF (carpeted fini 3h 130 watts Enclosure Materials, Structural, All with flying hardware), and the MTH-2.5/42BTC Sensitivity (SPL at one meter, indicated Versions: (carpeted finish without flying hardware). input power, anechoic environment, band­ 14-ply birch plywood limited pink-noise signal), MB/HF: Finish: The MTH-2.5/42BT mid-bass section utilizes 111 Watt: 105.5/116 dB Black carpet two high-efficiency, low-distortion DL 1OX 6001150 Watts: 133.5/138 dB Hanging: 10-inch mid-bass drivers coupled to a unique Beamwitlth (angle included by 6-dB-down Two-point flying system (tracks accept phase plug (U.S. Patent No. 4,718,517). An points on polar responses, indicated one­ New Haven NH 32102-1 fittings) Aperiodic Enhancer™ , this phase plug extends third-octave bands of pink noise; see Dimensions, the upper-end response by making use of the Figures 3 and 4), Height: 91.4 cm (36.00 in.) fact that only the apex area of the cone near the 900-20,000 Hz, Horizontal: Width at Front: 57.2 cm (22.50 in.) voice coil is in motion at the higher frequencies, 40° (+20°, _5°) Width at Back: 28.3 cm (11.13 in.) and automatically adjusts the acoustic loading 900-20,000 Hz, Vertical: Depth: 75.9 cm (29.88 in.) to maximize acoustic output. The output of the Side Angles: 15° each (30° wedge) 20° (+36°, _3°) four drivers is summed through a mid-bass Net Weight: Directivity Factor R. (Q), 800- to 20,000-Hz manifold (U.S. Patent No. 4.923,021) and 93.0 kg (205 Ib) Median (see Figure 5): coupled to a 40° x 20° constant-directivity horn. Shipping Weight: 31 .6 (+43.3, -16.0 ) The square mid-bass horn may be rotated to Directivity Index D;, 800- to 20,000-Hz 97.5 kg (215Ib) tailor the directionality of the system to match Median (see Figure 5): specific acoustic requirements. 15.0 dB (+3.5 dB, -3.1 dB) DESCRIPTION Distortion, 120 dB SPL at 1 Meter, Shaped The Electro-Voice MTH-2.5/42BT mid-bassI The MTH-2.5/42BT high-frequency section con­ Spectrum (see Figure 6), high-frequency loudspeaker system is a mem­ tains two modified DH1Amt-16 compression Second Harmonic, ber of the family of Manifold Technology® MT drivers manifolded onto a 40° x 20° constant­ 200 Hz:2.5% loudspeaker systems designed for high-level directivity horn. The modified DH1Amt-16 1,000 Hz: 1.4% sound reinforcement in concert-sound touring (1 .375-inch bolt-on version of the DH1 A, with a 3,000 Hz: 1.4% and permanent-installation applications. The modified magnetic structure) features a power- 10,000 Hz: 2.5% MTH-2.S/42BT SPECIFICATION GRAPHICS FIGURE 1 - Axial Frequency Response FIGURE 4 - Beamwidth vs. Frequency -HO 120 0. i:<II w W 110 ~~ ) g ': ID 11\ v, o .. 05 '"~1oo 1/ 1\ ..J Il. ~ : III f' ~ 20 90 -HORIZONTAL 0 ::I *VERTICAL A .. , , FREQUENCY IN HERTZ . .. .. ,- FREQUENCY IN HERTZ- - - t\ FIGURE 2 - Impedance vs. Frequency ~~ 100 I I I~ I I I IIII I I-HF Wi III ::Ii 31.5 f\ ::0: ~r. 0 / \... l...<' 0 W -HORIZONTAL 0 0 '" V\...,.. v I)\... z 10 / \ \'\r 1ft.,., *VERTICAL' A < '-V\.. , c MB- 1\ r-- . .. .. ,. ,- W -\. i-.r'- ../ Il. ~ FREQUENCY IN HERTZ-- - ~ 3.16 FIGURE 5 - Directivity vs. Frequency FREQUENCY IN HERTZ FIGURE 3 - Polar Response FREQUENCY IN HERTZ ~.,.,."~.' ,.' ~ ~.,.. 1251-k ,.. -250Hz . 1M' -100Hz FIGURE 6 - Harmonic Distortion 130 to" W ~'to" 120 , ' , ..' 1 " "\ 110 FUNDAMENTAL ! "."IItf ! 10' •I . lit' I 1I •· ,.. 1 kHz . '10' 2 kHz . 110" 4 kHz - - - 100 <D 'C :;;; 90 2nd HARMONIC l- -'c.. (f) '\. 80 IJ '\ It' 'II' • kHz '10" 111 kHz 70 r! \ 1'\ J \ 'j •• I 60 1/1 fl 3rd HARMONIC II , 11C,.... l1li" .. 50 I IIII \If ..........:"'.,'" 2030 50 100 200 500 1000 2000 5000 10000 20000 '10" 125Hz ,... 250Hz ,.. 500Hz .' - . - . - FREQUENCY IN HERTZ 2nd HARMONIC __ 3rd HARMONIC ............ .•.-~~ FIGURE 7 - Wiring Diagram · ,..,. -1 kHz ~~110' 2kHz 1111" 4kHz HF (' OHMS NOM.) . - ... 2, D-"CG"'R"'E"'E"'N------'------'''''''='''' 110' ,kHz ,... 1I11dtz. RED RED ·tIt"'e'"5 dB PER· - . - HORIZONTAL--- 1. OIVISION VERTICAL--- MB R..-JOHMS (I OHMS NOM.) ·long box axis vertical 1, l BLACK BLACK ful motor structure and titanium diaphragm for in an anechoic environment using a swept sine­ CROSSOVER, EQ AND SIGNAL DELAY maximum linear acoustic output, extended high­ wave signal. The Dx34digital electronic unit was The usable frequency ranges of the individual frequency response and accurate transient re­ used to provide the necessary crossover filters, MTH-2.5/42BT sections are 150-2,000 Hz for sponse. The outputs of the two drivers are equalization and signal delay. No high-pass the mid-bass section and 1,200-20,000 Hz for summed through the MTA-22 high-frequency crossover filters were applied to the low end of the high-frequency section. Crossoverfrequen­ manifold (U.S. Patent No. 4,629,029) and the mid-bass section. One watt of power (2.83 cies of 160 and 1,600 Hz with 24-dB-per-octave coupled to an HP64S hom. The HP64S is a volts rms at 500 Hz) was applied to the mid band slopes are recommended. For full-range appli­ member of the HP TransPlanar™ horn series of the mid-bass section. The sound pressure cations, one of the MTL-2B low-frequency loud­ (U.S. Patent No. 4,685,532) that features level was normalized for an equivalent one­ speaker systems is recommended for use with beam width-control vanes as part of the meterdistance. the MTH-2.5/42BT. For optimal acoustic perfor­ waveguide to correct the very-high-frequency mance, the Electro-Voice Dx34 digital elec­ beamwidth anomalies that typically plague DIRECTIVITY tronic crossover/equalization/signal-delay unit 2.0-inch-throat horns. The square high­ The directional response of the MTH-2.5/42BT is recommended. frequency horns may be rotated to tailor the was measured in an anechoic environment at a directionality of the system to match specific distance of 6.1 meters (20 feet) using 1/3- The Dx34 is a programmable, two-in/four-out acoustic requirements. octave filtered pink noise. A full spherical mea­ digital electronic unit which may be configured surement system was used. The Dx34 digital for stereo two-way, mono three-way plus All versions of the MTH-2.5/42BT are constructed electronic unit was used to provide thE) neces­ subwoofer, or mono four-way operation. Each of 0.75-inch thick, 14-ply birch plywood and are sary crossover filters, equalization and signal output section includes crossover filters, equal­ extremely well braced to survive the rigors of the delay. The polar response of the loudspeaker ization, limiting, signal delay, polarity and gain road. The MTH-2.5/42BTCF (flying) and MTH- system at selected 1/3-octave frequencies is adjustment; the parameters of which all may be 2.5/42BTC (nonflying) systems are covered with shown in Figure 3. The frequencies selected programmed and stored by the user. In the black Ozite Super TNT carpeting, the most rug­ are fully representative of the polar response of mono three-way configuration, the Dx34 in­ ged in the industry. The the system. The beamwidth of the system utiliz­ cludes a factory preset for optimal performance MTH-2.5/42BTCF system incorporates a two­ ing the complete 1/3-octave polar data is shown ofthe MT -2/42B loudspeaker system (the MTH- point flying system.