Can anyone explain stereo ignition interference?

[djbartu]

I've been getting a high pitched (changes with engine rpm) ignition interference noise from my front left speaker for quite a while - but with a little time on my hands yesterday, I decided to check out the problem. The only sound system variations (other than speakers) on my SHOwagon are a powered subwoofer and an interface to play my mp3 player through the CD changer wiring. Since the mp3 interface plugs into the factory wiring nothing was done but, I installed a high quality in-line filter before the sub. Here's the strange part, the interference noise now only comes through the front right speaker.

The noise isn't very loud, so it's no real big worry; but it seems strange that it's only one speaker and it moved another speaker.

By the way, I did check the grounds and all seem OK.

Any ideas?

 

[NebraskaSHO]

Do you have aftermarket speakers or a multi channel amp running the speakers? Im guessing you are using the factory set up with the sub's amp wired off the back speakers.

IF you have a multi channel amp (for your front and rear speakers) you could buy a ground loop isolator from walmart or a car audio place and plug it in-line with the RCA's. Worth a shot. Worked on my old car with the Subs amp. Gave it to a friend for his Mustang.

http://www.crutchfield.com/S-mnTnfxBbTt7/cgi-bin/ProdView.asp?search=ground+loop&i=127SNI1

Maybe the sound is coming out of both speakers but just is not noticeable anymore from the left one? Balance at 0? I'm not sure why a newer car would have this problem. Hopefully someone else knows more and will chime in! Good luck!

P.S. the SHOWagon is sweeeeeet

 

[naval-avi8or]

Alternator/white noise whine is 99.9% due to a bad ground within the stereo system.

 

[djbartu]

Alternator/white noise whine is 99.9% due to a bad ground within the stereo system.

The powered sub is the only component added (except for the mp3 interface which is directly plugged into the factory harness) and it does have a good ground. Where do I start to look for the bad ground? And, why only 1 speaker making noise?????