Have been having an issue with my SVS PB12-Plus subwoofer (ported box enclosure, 12" driver, 525 watt amplifier). When I first got the sub, it worked flawlessly, never had to run at high volumes, but a few times just for fun turned it up to likely about 75% gain and let er rip. Peformed without a hitch and absolutely shook my apartment building. Shortly thereafter, I moved to a new house. I moved the sub myself and was extremely careful, no bumps or anything. In the new house, my theatre room is probably about 50% louder than my previous room, with vaulted ceilings. So performance will obviously be different. But at my new place, I am getting very frequent cases where either a very loud "crack" sound, or sounds like distortion (blown speaker) are coming from the sub when it hits hard bass sounds (explosion in a movie, for example). Now, this is *not* running the sub at really high volumes. This problem occurs with the amp at or below reference volume, and the gain on the sub at 50%. I have tried moving the sub to different parts of the room. I should note, this is a very old house, and the wiring is pretty substandard, so one thing that makes me wonder is if insufficient current might cause this problem? I've owned this sub for probably a 3-4 years now, and the problem started happening about a year in. Having a kid cuts down on my home theatre time. Could anyone offer some advice on what they think the problem could be? Any suggestions on things to try so I might be able to get a pretty firm idea on what the actual problem is? Thanks!