ok, so maybe you can't plug any ol speakers into the PA head. we played a show saturday, and the club had some decent columns we thought we'd use intead of bringing our own. i still don't understand the whole "ohm" thing, but from what my PA head owners manual read if the speakers were 4 or 8 ohms i was safe. the speakers didn't say what they were. so we hook everything up and one speaker is not working. fiddle around a little, unplug the speaker and get a little show that KISS would be proud of. fire literally shot out of the amp and the place filled with smoke. luckily, the club had a head to go with it's speakers and we were able to do the gig. i'm assuming that the cause of this was the speakers cuz that's what i was told when i returned the head for repairs. anyone know of anything else that may have caused this to happen - any similar experiences? i'm also assuming the warranty is going to cover this. there were no explicit warnings in the owners manual.