Today there are 7 basic sound system designs and many variations of each. Since there is no written official standard for trades people to follow, the performance of a system's design can vary tremendously. When ceiling height permits, the speaker is mounted between 25 to 32 feet high. Generally this gives excellent coverage and first reflections are off people and not back walls. This coverage pattern greatly reduces common feedback problems.
Speakers creates overlapping interference patterns which creates dead spots.
For best performance, expensive, high quality, well behaved speakers should be mounted as close to the ceiling as possible. Very high cost system to do. Generally not very good for music unless you can double the cost of an already system design. System requires 70 volts distribution An amplifier for ever row of speakers Not recommended for minister who like to roam around with wireless microphones. Speakers creates overlapping interference patterns which creates dead spots.