The last time I let someone use my amp / cab ( they were going on before us)... by the time I got to plug in, the settings were all over the place ( not a big deal as easily re set) but...he'd somehow blown the little "tweeter" thing in the top corner of the cab..... As it happens I was at the time favouring a very bassy sound for what I was doing so didn't really care that much about the "squwarker" thing, I just pulled the wires off and carried on...but that's not really the point is it. The universal experience throughout seems to be that "you let people use your stuff, it gets Fkd.... "