User manual ELECTRO-VOICE DC30B

[. . . ] Each driver is integrally mounted to the fiberglass horn bell via a heavy-duty mounting bracket and propri- Ring-Mode Decoupling (RMDTM) The MH4020AC controls both acoustical and mechanical ring modes to provide dramatically increased intelligibility, using techniques learned from the development of the Electro-Voice X-ArrayTM concert speakers. There is much less coloration of the sound from resonating sources, leaving only the intended sound to be heard by the audience. Installation Suspending any object is potentially dangerous and should only be attempted by individuals who have a thorough knowledge of the techniques and regulations of rigging items overhead. Electro-Voice strongly recommends that the MH4020AC be suspended in accordance with all current national, federal, state and local regulations. [. . . ] Equalization can be easily applied with a graphic equalizer to give a flat response. The high-frequency compression driver can be equalized with a graphic equalizer or an EQ module inserted into the Electro-Voice XEQ-2 (two-way) or XEQ-3 (two-way or three-way) active crossover/equalizer. The EQ module should be selected to suit the particular compression driver and the HP420A horn (see relevant data sheet). Because of its use in large arenas, where air loss can be significant, it is recommended that the system be equalized "on site" for optimum results. The XEQ-3 and the mid-bass EQ module from the EQMT-2 can be used to provide a good starting point for the equalization. 2 Electro-Voice strongly recommends the use of a 100-Hz high-pass filter to protect the drivers from unnecessary excursion and thermal stress. Connections The four DL10X-SH drivers in the MH4020AC horn have a nominal impedance of 16 ohms each and can be accessed individually and driven independently. However, it is more typical to combine the drivers. Figure 9 illustrates some different combinations. It is particularly important to bear in mind the impedance of any cabling and specifications of the amplifier before selecting a specific combination. Whatever the combination selected, the polarity of the drivers must be considered (see Figure 9 and Polarity of the DL10X-SH Drivers section). Directivity The axial directivity factor R of the MH4020AC was computed at each of the one-third-octave center frequencies over the frequency range noted from the horizontal/ vertical polars shown in Figure 7. This shaped signal MH4020AC Coaxial Stadium Horn System MH4020AC Coaxial Stadium Horn System is then further filtered with an 80-Hz, 12-dBper-octave high-pass filter to prevent out-ofpassband displacement. The amplifier is set to provide 1, 200 watts into the 6. 9-ohm EIA equivalent impedance (91. 0 volts). Amplifier clipping sets instantaneous peaks at 6 dB above the continuous power or 4, 800 watts peak (182. 0 volts). During this test, the midband section is not high passed at 1, 600 Hz. The high-frequency section's power handling is dependent on the selected driver combination. Please refer to the relevant engineering data sheet. Architects' and Engineers' Specifications The horn shall be of the constant-directivity type. It shall produce a horizontal beamwidth (6-dB-down angle) of 40°, deviating no more than +20°/­5° from this angle over the range of 350 Hz to 20 kHz. It shall produce a vertical beamwidth of 20°, deviating no more than +30°/­5°over the frequency range of 350 Hz to 20 kHz. In addition, it shall provide an acoustic load to below 100 Hz. The MH4020AC mid-bass section shall operate over the range of 100 Hz to 4, 000 Hz, with a recommended crossover frequency of 1, 600 Hz, and be driven by four 10-inch, weather-resistant drivers with high-technology cones of Kevlar® and epoxy. 1 The patented Manifold Technology® technique shall be exploited and result in a power-handling capacity of 1, 200 watts per EIA Standard RS426A. [. . . ] Some states do not allow the exclusion or limitation 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 defects in materials or workmanship for a period of five (5) years from the date of original purchase. The Limited Warranty does not apply to burned voice coils or malfunctions such as cone and/or coil damage resulting from improperly designed enclosures. [. . . ]