Stereo noise - not alternator noise

[nicbeer]

need some help:

ok, not in a forby but in my 99 proton.

I have a clarion deck,coustic xm3 crossover and 2x amps. 1 for sub and the other for front speakers.

There was no problem till i have put the front speaker amp in back in.

Problem: There is a noise similar to alternator noise but is apparent when any device is turned on, eg lights, motor, fuel pump. The noise does not go up or down with the revs either. The noise was not there before i put the amp in. Before the front speakers were hooked up the deck amp and not through the amp or crossover. I do have a noise suppressor thingo near the crossover. it seems that when i have the neg hooked up there is more noise?

I am getting the negative from a bolt that is also bolting the rear seat to the body.

I had this amp in there about 6mouths ago but took it out to use in the zook. can't remember there being this much noise in there.

I believe there is a earth loop happening but unsure where to find it and how to fix it.

cheers all

Nic

[murcod]

Try improving the earth connection- make sure it is bolted to a solid point and gets a good connection (ie scrape the paint off the body.) The power wire should be run directly to the battery positive too. Use heavy duty cable for all connections.

If that doesn't help then try running a heavy duty earth lead all the way to the battery.

[Slayer]

sounds to me like one of the speakers or the cross over is earthing on the body some place...

[udm]

Make sure you don´t run power and signal cables together, Ive got power running on one side while audio on the other side of the car.

[nicbeer]

Found it i think. seems like a dodgy crossover. looks to have a dry joint in there and is earthing on the RCA cables.

hmmm. to find it thats the question...

cheers