Here's the deal. I was practicing in the family room tonight and noticed a wavering in my volume level (not that high to begin with) . I stopped for a minute and started again and everything seemed fine. Tuned things off, took a break and came back. When I started again, there was a bad "vibration" or buzzing sound. It seems to be coming from both speakers and the tweeter. I tightened the screws on the speakers and the grill, checked the cable connections...no change. I have a yorkville xm100 and tried the bass in that (it's a Jack casady bass) and that sounds fine. The rig is a Warwick ProFet II amp, solid state and an Avatar B212. Have I fied something in the amp...fuse? Help...I don't have a clue!