So.. I have a Sundown SA-8 with 400 RMS.. a kicker amp w 400 watts.. one day my sub just stopped working, cut out. It would occasionally cut out on certain frequencies it seemed like in certain songs, like it would shut down for a few seconds and come back on. But not often. Anyways, the sub appears to be in no way blown, the amp is providing power. Replaced the RCA's. No fuse's appear to be blown. I'm a real rookie when it comes to car audio, but what could be the problem here??? Also, we took the sub and attached it to a home theater, and it works fine. So the sub definitely isn't blown.
ANOTHER NOTE: The "protection" light on the amp is completely dim.