Something else to keep in mind with sound reinforcement is to use the BIGGEST amps you can find, 2x power rating of drivers isn't out of line. You never want to allow your amps to clip running at the power levels you will be using, much better to let the drivers see too much power than not enough with a bunch of distortion in the signal, sure fire way to fry a speaker.Ideally you want an amp that is big enough that it's basically idling the whole time , nice clean signal. JBLPro.com has some good tech articles about PA aplications. Kelly