Weird speaker problem

[fast64]

Recently in my dad's 01, he says the door speakers have been making a constant, loud "thud" whenever the stereo is on. He took the door panels off and noticed the cones of the speakers get "sucked" to the magnet as soon as the stereo is turned on and stay there until it is shut off. It seems to me like the speakers are getting a constant voltage, but I am 2 hours away and haven't gotten a chance to look at it yet. Any suggestions on what it is for him to check it or me too when he comes to visit me next weekend?

[OsirisGuy]

It sounds to me like the "negative" lead on the speaker is getting a constant voltage, or a switched voltage. Is it a stock audio set up?

[fast64]

Yeah, its the stock Mach 460 stereo.

[OsirisGuy]

Is it all the speakers or just that door?

My thoughts are pretty much the same as yours. I'd check behind the radio and the speaker leads. Make sure the speaker wires are not grounding out or spliced and power is touching. Same with the speakers, although I would think even if the positive lead is grounding out the speaker would still somewhat play.

You may also find the problem at the amp(s).

[fast64]

Its only the door speakers.

[sledgehammer]

sounds like and amp to me. the amp contols power to speakers the deck just powers and directs the amp. and I am 99% sure the two amps are front and rear. so the front one is probably jacked up some how.