I have a 2007 Scion tC with the factory sub option installed.

Recently, there seems to be an issue with the subwoofer or something to do with the audio system in the rear of the car. There would be excess thumping that comes from the rear of the car and the best way I could describe it is that it sounds sort of like what it would sound like if someone was beating their fist against the floor of the trunk. I'm pretty sure it has to do with the woofer but i'm not sure what the problem is.

Now, before you suggest I just have the volume turned too high and the thumping is just excess emphasis on what should be quieter bass beats in an audio track, the issue is much more prevalent when it's not music playing. Like if I had the news on, it would just be thumping like mad.

One of the things that is driving me crazy is that it's not something manually repeatable. Like I could pop in some random drum and bass track just to try and emphasize the issue and i'd get maybe a few phantom thumps and that's about it. Some tracks, it doesn't occur at all. But i'm sure it's an issue since there probably shouldn't be a lot of heavy bass which plays during a news broadcast.

 

I think it may be the lack of x-overs on the factory sub/HU... Upgrade to an aftermarket sub/amp combo with a LPF and I think that'll solce your problem..

 

Definitely doesn't sound like clipping. Kinda sounds like a short or something. Or maybe the remote turn-on is momentarily powering the sub on/off, but not long enough for the turn-on thump circuit to activate. Either a wiring fault or something's going in the amp.