I have a Peavey 4x10 rated 350w @ 4 ohm 700w peak. I'm pushing it with a Ampeg rated at 450w @ 4 ohm (so yeah, I'm probably over powering it). I normally use my sr506 with this set up and havn't had a problem. However, I used my passive p bass (the pickups are hotter than my active bass). I have been pushing it hard to get loud enough to be heard over 2 guiturds. Around the 3rd set the cab started distorting and breaking up pretty bad. I swapped basses and the sound was still there. I can't see any physical damage, but I've never blown a speaker and don't know what to look for, so I wanted to know if I have done just that.