My trusty Cambridge Soundworks SW1 powered sub may finally be on it's way out. Been great since I purchased in the late 90s. When watching a movie during some loud bass scenes, I can hear a "clunk" sound coming from the 12" woofer. Doesn't happen all the time. Just during extra loud scenes. Nothing's loose inside. I suspect the woofer is on it's way out. Even worth trying to repair? I've had it so long, I don't even know where to start looking for a comparible one to replace it.