I have DriveRack PA or PX hooked up between the amps and the mixer to handle feedback. My low volume project, doesn't need them at all. (I don't bother setting any of the filters. The active filters might kick in from time to time.) With a loud band, I have to set the monitor DRPX and the FOH DRPA (or PX depending upon what configuration I'm using.) Still the DriveRacks will notch the feedback quicker than I can reach for an EQ slider. Living on the edge of feedback isn't fun, but good anti-feedback units can make it easier to live with. It's just better to turn it all down a bit and not even be close.