I'm sure this has been covered before but I don't have time to scour forums for this specific topic. So sorry if I'm rehashing old crap, and all apologies (get over it) to those who may be butt-hurt over seeing the same stuff repeated on forums lol I have a GK 400RB/115 combo, bought used, it sounded fantastic in the store and at mid volumes at home, but when I cranked it at practice, the speakers were farting like they ate 12 buckets of beans the day before. Bad distortion (clean channel), no increase in volume after about 3/4 turned up on both volume controls, absolutely no low end (had to turn bass boost and EQ bass levels to zero to alleviate the distortion) and keep all tone knobs on my bass mid-level to keep tone flat. My sound sucked. I realize I'm limited on things with a combo of this size but I wasn't expecting it to sound this bad. Anyone have an idea of what could be causing this issue and how to fix it?