Properly applied, the results attained can be dramatic. In many cases installations in highly reverberant spaces or acoustically difficult spaces have produced the first intelligible speech ever created by a sound system. However, be careful not to consider these products magical or superheroes. The laws of physics and acoustics still apply.
The products in this roundup are largely defined by three major performance criteria.
First, the distance they are capable of reaching with intelligibly speech, which is broken down into small, medium, large, and very large spaces. The definition of those breakdowns for the purpose of this roundup is as follows:
Second, the maximum Sound Pressure Level (dbSPL) the speaker is capable of producing.
Third, the lowest frequency achievable where the speaker can still maintain pattern control and steering capability.
These three criteria will help you decide which products might meet the application you have in mind.
The maximum distance specification is to some degree theoretical, since the actual performance of any product will depend on the acoustics of the space, the amount of reverberation or bounce present, the height and aiming of the array and a number of other factors. The specifications we list (taken from manufacturer supplied data) are for reference and side-by-side comparison purposes, and as they say your mileage may vary.
Maximum Sound Pressure level is a function of two things, the size of the array and the number and size of the loudspeakers contained in the array. The larger the array, the louder it will (theoretically) get. Driver size, while important, is not always vital to the overall performance of the array. Driver size can have some influence on the third criteria, low frequency limits. It is strongly recommended that you do not use driver size as a comparison