User manual ELECTRO-VOICE MH6040AC DATASHEET

[. . . ] Manifolding allows the output of two or more drivers to be summed without the usual detrimental interference problems in the passband. There are a number of additional advantages to manifolding, including reduced distortion (see Figure 5) and increased efficiency at certain frequencies. There is also redundancy built into the system; in the unlikely event of a driver failure, one remains available. The DLX10-SH drivers are contained and sealed within fiberglass covers optimally tuned for maximum low-end performance and displacement control. [. . . ] Directivity The axial directivity factor R q of the MH6040AC 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. Directivity index (Di) was taken over the same frequency range. Beamwidth Plots of the MH6040AC's 6-dB-down total included beamwidth angles are shown in Figure 6 for each of the one-third-octave center frequencies noted. Polar Response The directional characteristics of the MH6040AC were obtained by selecting the horizontal and vertical details from a full set of polar data measured in EV's large anechoic chamber. The measurement microphone was placed 6. 1 m (20 ft) from the center of rotation of the horn which, in turn, is 0. 94 m (3. 08 ft) behind the mouth of the horn. Polarity of the DL10X-SH Drivers For Manifold Technology® to operate correctly, the drivers must be operated "in phase. " In other words, for parallel connection, the DL10X-SH's must be connected so the negative terminals of the drivers are connected together, and the positive terminals are connected together. Service In the unlikely event the MH6040AC requires service, each DL10X-SH easily can be replaced or serviced by removing the back cover and then removing the driver. A service data sheet is available from ElectroVoice. 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 conditions. A random-noise input signal is used because it contains many frequencies simultaneously, just like real voice or instrument program. The signal contains more energy at extremely high and low frequencies than typical actual program, adding an extra margin of reliability. The test combines 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 average, just like actual program. The long-term average level stresses the speaker thermally (heat). The instantaneous peaks test mechanical reliability (cone excursion). Note that the sine-wave test signals sometimes used have a much less demanding peak value relative to their average level. In actual use, longterm average levels exist from several seconds on up. The test performed lasts for eight hours, adding another extra level of confidence. Specifically, the MH6040AC mid-band section is designed to withstand the power test described in EIA Standard RS-426A. The EIA test spectrum is applied for eight hours. [. . . ] Exclusions and Limitations: The Limited Warranty does not apply to: (a) exterior finish or appearance; (b) certain specific items described in the individual product-line statement(s) below, 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 owner's 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 ElectroVoice Service or any of its authorized service representatives. Obtaining Warranty Service: To obtain warranty service, a customer must deliver the product, prepaid, to Electro-Voice Service 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 Service at 600 Cecil Street, Buchanan, MI 49107 (800/234-6831 or FAX 616/695-4743). Incidental and Consequential Damages Excluded: Product repair or replacement and return to the customer are the only remedies provided to the customer. [. . . ]