Ok, I posted on here about a problem I had when I first got my car and was wiring in the stereo system. No one had ever heard of anyone having this problem then, so maybe now someone has run in to it.

Here's a quick run down of the equipment:
Pioneer DEH-8600 head unit
Polk Audio components up from, 6x9 3-ways in the back
TREO 15" Woofer powered by Concept CC-D800A amplifier

Now, here's the problem. I get noise in the speakers unless I power them directly from the head unit.

I have some Monster Cable RCA's running from the head unit's out to the back of the car, where I had the amplifier for Polk speakers. Power for the amp came directly from the battery. Ground cable was 1' long and grounded to the body.

Turn on the car, and BOOM huge amount of computer noise coming from the speakers.

I made sure my RCA cables and speaker wires didn't run near any other wires and that wasn't it. I even went so far as to take out all the speakers and head unit it, move them to the trunk and hook them up with some short wires, and the noise was still there. I tried 2 different head units (other was a JVC, can't remember the model). I tried several amplifiers, my concept, an Autotek, a JVC, and a Sony. All the amps showed the same problem too. I even tried different speakers (Infinity reference speakers).

Just for the hell of it I disconnected the car's connections to the battery and only put in the stereo, noise gone. So the noise is definitely coming from the car.

What could it be???

Currently I have the speakers powered by the head unit, and there's no noise... but not quiet as much power either

I'm able to, using the low pass filter on the concept amp, eliminate 99% of the noise from the subwoofer (There's still a low hum, but not that noticeable unless your back by the woofer)

I even tried taking the speaker out of the head unit, running in to a line level converter, then to the amp, with the same results. So the noise is coming from the connection to the battery.

Another thing I did, just because I was completely baffled, was hooked the stereo and amp to an EXTERNAL battery from the car... noise wasn't there. So, definitely electrical system, but what is causing it, and how can I eliminate it from the stereo??

Any suggestions?

I have a video around here somewhere with the noise in it. It's a computer noise.

-Dave

 

Let me see something,

Just for the hell of it I disconnected the car's connections to the battery and only put in the stereo, noise gone. So the noise is definitely coming from the car.[ Power for the amp came directly from the battery. Ground cable was 1' long and grounded to the body. Sounds like you might be getting interferace because of a ground that is not electrically connect good enough.

Try taking a wire and ground to the neg term of the battery instead of the body. I just recently rewired the whole power system. There is also a ground lug behind the battery this is originally where I hooked up my ground prior to the rewiring and had no problem. Here is a pic of the new install and the arrow point to the ground lug behind the battery below the lip. Hope this helps. Just thought of something else!! There is a lil plug that goes into the stock radio system, I think it has 3 wires going into it. It is the cars computer buss. If you used this for switched power that might be your cause also. I tapped off the lighter for my switched power.

 

Already tried it. I used the ground block near the battery first, then went straight to the battery. Same problem in both locations. I also went to the cigarette lighter for switched 12v.

 

well im outta ideas, hopefully someone in the audio forum can help.

 

yeah, I have a friend that manages a car audio shop here, and even he is stumped..

more info, I had the boston acoustic system in there from the dealer, but my new system was run completely seperate from it. new speaker wire, power, etc. the unused boston acoustics amp is unplugged, but still sitting there. I wanted to be able to replace all the stock stuff in a hurry if I needed too (JUST in case I wanna get rid of the car several years down the road)

 

I am a complete amateur and may not have read your description correctly, but have you tried grounding your amps and head unit to the same point? This solved a pesky ground loop/alternator whine problem I had a while back with my Stratus.

 

Yeah, When I hooked the headunit up in the back of the car everything was grounded at the same spot. Same noise. It's noise being introduced in to the cars wiring system somewhere, somehow.

 

Angry Pickle, I have done installs on a few Magnums and 300's and have not ran into your problem. I have a few friends in different city's who own shops and do installs and nobody has ran into your problem, since last year when you first posted about it.
I wish your were in my neck of the woods so I could take a look and poke around. I hope you get it worked out.

In about a week I will get to rip into a new Charger.

356, I have watched your install, when I check in here every so often and it looks awesome. That is a cleaner install then many pro's I know would do. Good Job!


Redhouse

 

Yup. That's the general thing I get... people staring at it and scratching their heads

My friend with the stereo shop has also done several other magnums with no problems at all.

I just don't know what else to try... except another car

 

What about running all new wires for the Stereo System? Your friend runs a shop he should be able to run all new wires. That's what I do if I couldn't find the problem and it's cheaper then a new car.

Redhouse