If you need to supply sound to a fairly small room, say 31'14 feet x 32 feet x 10 feet high or a room volume of 10,000 cubic feet, the system design shown in Figures 8 and 9 shows a typical setup that will usually work well.
The system shown is one that would be a typical portable setup using a pair of E-V 512-2 speaker systems. For increased dispersion and coverage in the midrange, a pair of 515-3's could be used in place of the S12-2 'sin this particular room, either the 512-2's or the 515-3's, when hooked up to a two-channel power amplifier capable of producing 50 watts per channel with both channels driving an 8 ohm load (such as the TAPCO CP120), will be able to produce average midband sound pressure levels of 106 dB in the reverberant field of the room. Figure 6 in the "Room Reverberation Swamps Your ~ice" section starting on page 4 will refresh your memory on the concept of reverberant field. System headroom before amplifier clipping is also great enough to reproduce 116 dB short-duration peaks (10 dB above the long-term average level), so your vocals and instruments will stay clean and undistorted. Remember, these 5PL's are the most this system can do - chances are you will need only 85 to 100 dB depending on the type of material you are playing. You may want to refer back to the chart in Figure 7. For increased dispersion and higher sound pressure level, a pair of Dominators could be used in place of the S12-2's. The Dominators, because their efficiency is about 15% compared to 5% for the S15-3, will be capable of producing 111dB average sound pressure levels, with peak sound pressure level capability of 121 dB. Figure 10 shows the "block diagram" - which shows how things are connected together - for a complete system employing one channel of the p6wer amplifier per speaker. This connection will produce a "monaural" system, which is more practical than "stereo" in such a setup. With a stereo arrangement, you would risk having part of the music on one side, and part on the other, with only the people near the middle of the room hearing it all.
For more headroom and higher sound pressure level capability a two channel power amplifier capable of producing 150 watts per channel with both channels driving an 8 ohm load (such as the TAPCO CP5OO) could be used in place of the 50-watt-per-channel power amplifier previously described. With the 150-watt-per-channel power amplifier, the S12-2,5 or 515-3's could generate average sound pressure levels of 111 dB and peak sound pressure levels of 121 dB. The Dominators would be capable 0 producing 116 dB average sound pressure levels with peak level capability of 126 dB. If you wanted a mixer with reverb, you could use the TAPCO 6000R in place of the TAPCO 6000C1 mixer shown. Other substitutions and additions could be mad to suit your own personal needs. If you are designing a system to be permanently installed in the same room, you could mount a pair of P112-2 or PI1S-3 speaker systems on the wall dos to the location shown in Figures 8 and 9.
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