I have had this system up and running fine for over 6 months. Recently on several different occasions while listening I hear almost like a loud bomb and the sound goes distorted. I have gone thru all the troubleshooting technics, rewired the amp, and still getting it. It doesn't seem to be triggered by anything in particular and happens after almost no time of listening. The amp is not hot either? Does anyone have any ideas before I try to return the amp?