Well, this is my perdicament. I'm in a local metal band who plays at extreme volume levels. The amp i'm currently using is a 400w 1x15 Peavy Mark 3 Combo, which although very powerful, cannot match their volume. I was wondering if hooking up a 4x10 400w cabinet would help kick up my sound a couple extra volume levels? The back of my combo has two outputs for hooking up extentions and I was thinking I could use a Y cable and hook up the extention? Would more speakers help me get to the higher levels I need to reach, which are only about 200watts more? I really don't want to end up getting a 1000w 8x10 combo if at all possible, due to the extreme expense. Any help on the subject would be benifical.