I just got back from a 2hr road trip and i noticed that after i turned my deck off, the subs still seemed to be on They seem to be emittting a low, constant rumble, even when the deck is off. What's even more confusing is that the noise goes away about 2 seconds after opening the trunk. Anyone had a similar problem? My amp and subs are going on about 5 years now, so maybe its time to replace them. Any help would be appreciated.