JL install - huge suppresion problem!!!! help!!

Post Wed Sep 21, 2005 7:46 am

Guys, I have just fitted 3 JL amps, 2 12" W3 subs and their top line components with a pioneer 77 headuint.

I have a huge suppresion problem - with the car on, alternator whine is audible through the front speakers. The install is text book stuff - earth is on the grounding point, all cabling is 4 gauge, and RCA leads are Streetwires zero noise.

I had exactly the same problem on a rockford install in my 325 sport. What is the problem? I cant take it any more!!! I was sooo careful this time aswell to ensure this didnt happen again!

There must be something simple I've missed!!!!

Please help, otherwise i'll rip it all out.

Car is an 88 E30 M3.

Many thanks.

Post Wed Sep 21, 2005 8:24 am

make sure there is an insulator between ure amp and the car body.... eg a peice of wood.... and they arent drilled straight to the body...

Post Wed Sep 21, 2005 6:23 pm

through the front speakers only? ensure they are mounted to wood (mdf) too and not grounding.

else try running a flat earth strap from the hu earth to the amps earthing point. the amps are all earthed to the same point aren't they?

paul

Post Thu Sep 22, 2005 7:47 am

Hi,

Yeah, noise through front comps which have their own amp. All amps are grounded to grounding point next to battery. I just dont know what it is and its starting to psss me off now!

Surely this is an E30 problem? I had the same fault with the install in my 325 Sport.

Anyone offer some more advice here? Have i missed a trick with E30's?

Post Fri Sep 23, 2005 6:15 pm

if you got to halfords the sell noise surpressors which fit inbetwen you speakers and the headunit and some of them go in the arial jack but if you fit one of these it should get rid of the whistle! had same problem in mates 318i e36 and fitted one and problem went!

Post Sat Sep 24, 2005 5:02 pm

no known problems with e30 installs. noise suppressors are a last resort - best to fix the problem. are your amps accessible enough to run the rears from the front amp to see where the interference noise is coming from?

paul

Post Sat Sep 24, 2005 7:42 pm

Try plugging another source into the offending amp and see if it makes the noise then. I think it might be the head unit side. Then try with one of the sub amps unconnected and if it doesn't do it then, you'll need a noise suppressor.

Your amps should have noise suppressors anyway! It's normally cheap amps that don't.