I've have an elemental designs nine.1 amplifier running a 12" x.x.x (for about 8 months). The other day I was listining to to it like normal and the bass all of a sudden disappeared. Ive checked everything physically. It turns on with remote wire. It getting power. The speakers are connected. I was thinking I would get a voltage tester and test the RCA voltage into the amp and then the voltage out. Would that be a good way of knowing if its the amp? Its still under warrenty so Ill send it back. Thanks