After reading a lot of positive reviews here, I picked up this Shuttle combo last week. I took it to one practice, and decided to try it out at a show last Friday. I was REALLY impressed with the tone and volume that it gave me. However, about 6 songs into the show, it crapped out; the 12 quit working. I took it back to the dealer over the weekend; shouldn't be a problem getting a replacement. My question is, was this most likely defective, or is it possible that I was pushing it too hard? The preamp was set so there was no clipping; the master was probably 3/4, and didn't notice any clipping. I was getting pretty good volume out of it, didn't notice any degrading of sound. When the dealer removed the 12, it wasn't frozen or scratchy when pushing on the cone. I'm hoping this was a fluke. If it was my fault, I don't want to go and do the same thing at the next show; and I don't want to have to baby it in fear of it crapping out on me again. Do those who own this combo push it reasonably hard without issues?