[Lonman]

Problem is with the eliminators is that how it works is it senses frequency spikes basically over a certain threshold & will cut that frequency. Now what can happen is you get a powerful singer that can naturally create these spikes without it actually being feedback, but it will still cut those frequencies which actually starts harming the sound. The cheaper ones like the Behringer are pretty much worthless in this respect. There are others that are a little spendy that actually work well when set correctly. Sabine makes a decent one & dbx also has a pretty decent one.

A good 31 band eq can be very effective & along with Jim, the ringout of the system needs to be done 3-4 times until you are at the typical volume level you would be running. Also when pulling those frequencies down, I also pull down the 2 adjacent frequencies a smidge.