The set up on my bass has been questionable for some time, and i've been blowing speakers. I'm pretty sure the power section and drivers are working properly. That said, can improper setup and intonation send a potentially bad signal to the amp, causing the speakers to be overworked, i.e. sub-harmonic stuff?? I am tuned low a,d,g,c on a P-bass with 130 gauge strings btw.