i'm using a Yamaha EMX66M 600 watt powered mixer w/12 in Peaveys...4pc live (i'm not recording) rock band w/vocals only going through the mixer/pa. any rule of thumb as to eq settings on the graphic equalizer? (i.e. add some freq "X"/or cut on freq "y"). and what are the sweet frequencies to boost for fullness and the "in frontness" that vocals need?