Voice-only System Design Using the M4: Rent Com Inc: Audio Visual, Video, Projection, Presentation Rental AV Equipment

Voice-only System Design Using the M4

Voice-only applications, such as paging and warning systems, are often required to operate in difficult environments or over very long distances. The characteristics of the M4 make it ideal for these applications. Let us consider the design parameters for such a system.

A human voice has the highest power output in the 500Hz octave band. Consonants of speech (essential for articulation) are centered in the 2kHz octave band. A good voice device should provide high acoustic output and pattern control over a passband that extends to either side of these two critical octave bands.

The unequalized response of the M4 is from 200Hz to 2000Hz. Given the M4's robust construction, this can be equalized within 3dB of flat response out to 4kHz, extending its response through the articulation range for human voice. Used with the proper horn, M4 completely satisfies the requirements for a high-level, voice-only system. The chart shows the levels that can be delivered by a single M4 at various distances with two typical horns. As always, these are conservative estimates based on the M4's capabilities at the lower limit of its passband. With proper equalization, M4 can typically exceed these levels by 3dB.