whistle noise from front comps!

[beeson100]

Took my head unit out the other day to try the girlfriends in instead, but now i've replaced it back with my one the fronts make a whistling noise that changes in pitch with the revs on the car! I've got comps in the front powered by an amp and a separate amp for my sub. It appears to be the amp for my comps because when i turn the gain up it gets louder, so i've checked all the wires to do with it but they seem fine.
any ideas anyone? it's really annoying!

Cheers
John

 

[KevHull]

Alternator Whine..

The amp will need earthing better

Thanks
Kev

 

[beeson100]

cheers kev. not sure why its only just started doing it though. its had the same earth point for about a year with no problems before? i'll give it a go. ta

 

[Kev]

It may have moved slightly....if it is earthed to painted metal, sand the paint off, it gives a better connection !!

Ta
Kev

 

[beeson100]

tried moving it, and using the same earth point as the sub amp (not at the same time) and it still does it. its really annoying cos i cant listen to any music without this really high pitched whistling! could it be the earth for the stereo perhaps??

 

[Kev]

Are you running your RCA and speaker wires down the same side of the car ??

Kev

 

[Tom]

It will be the HU earth.

 

[beeson100]

where abouts is that then tom? hopefully not somewhere i have to take loads of bits off to get to!

 

[beeson100]

anyone know?? i need to sort it out cos its driving me mad!

 

[Tom]

It will be on one of the blocks on the back of the HU.

 

[beeson100]

isnt there a wire going from the stereo to the earth point? along with the power etc

 

[Stu]

Ive tried improvin my head unit earth before and its hasnt worked, a ground loop isolater from maplin may help?
Stu

 

[beeson100]

its still f****d. what colour is the earth wire? and where does it end? if i cant find it i may have to run a new one to somewhere else

 

[beeson100]

anybody?? someone must know!

 

[iwan_canobi]

I had the same problem, changin the earth never worked for me so I bought a ground loop isolator as mentioned from maplin, it got rid of it straight away. Prob the easiest option, just plugs in in-line with the rca's. I know how u feel tho, it drove me insane hearing that whine!


iwan_canobi

 

[Tom]

Do you not have a manual for the head unit?

 

[beeson100]

yeah i've got a manual but its absolutely useless. i've just ordered a ground loop isolator so i'm hoping that does the trick. cheers for all responses