Interference from engine coming through speakers?!!

I think my cars possessed! Im getting a really high pitched whining noise coming through my sound system when I accelerate/decelerate. It varies in pitch depending on how fast I'm going! Ive got 2 12" subs and 2 6x9's in a custom build running through a 1000 watt amp with a Sony head unit. Someone suggested that it may not be earthed correctly? The boot builds been in for about 6 months and its just started happening over the past few days. Its driving me crazy! Even does it when stereo is off.

had a similar problem years ago in a bmw.  if i remember right, i had to have a thingy called a suppressor fitted - no idea what it is, looks like or goes but it worked!

not a lot of help i know…….

I had that on my portable stereo I have on my passenger seat!  It happened when i accidently switched it to MW wave!  I thought it sounded like a mini supercharger so kept it on for a whole journey lol! ops:

i had this problem in my astra . check your earth first . then make sure none of the cables (RCA , poss , neg , speaker etc) are to close to each other or touching . they need to be as far apart as posible . if its not any of them then i would say your amp has had it . try another amp if you can just to make sure .  :wink:

It will an earth problem either internally in your amp, or a bad ground earth in your wiring. Make sure it's clean of paint got a good fixing, and ideally on a main part of vehicle chassis, not to a spot welded panel.

Supressor won't work on this car alternator is already suppressed only a handful of manufacturers don't have supressed alternators

A few other people suggested it might be the amp too or the altenator on its way out. Thanks for confirming my suspisions! (bad speeling i know!). Ill try a tester altenator 1st as its a cvheaper option. Let you know how it pans out. Thanks  :y: