Strange sound through speakers

[azz00]

Hi all, not long ago I installed new speakers and amp in my car and now when accelerate i get a whinning noise through the speakers, the more a press the louder the sound gets.

I have allready checked the grounding point on the amp aswell as a few other things but nothing worked and basicaly im out of ideas so anyone else got any?

Btw its a JBL CS60.4 amplifier that is powering some fusions and some ground zeros.

Thanks.

 

[wallop]

With system switched OFF remove the RCA leads from the amp...

Start the engine & switch on the stereo as normal...rev engine...

Noise still present indicates a 'ground loop'....
Relocate amp earth to a better site & ensure its attached to bare metal godd & tight...

Noise not present indicates issue is before the amp....
Could be faulty RCA leads or earth track issues....

Post results, will go into more detail if fault still present....

 

[agithegreat]

I had a cs60.2. The 2 channel version of that amp. Same problem... I determined that it was the amp in the end... May not be the same for you though.

 

[Muttley1]

How long is the earth cable? You want it to be as short as possible!

 

[azz00]

Thanks for the replies everyone...

RCA's out and engine on... nothing through speakers

and the earth cable cant be longer than a metre? And i have used the point where the rear light grounds.

 

[nickwrxstiv2]

I think the noise you are experiencing is to do with electrical current and the alternator. Did you lay your power cables down the same route as the RCAs? You should think about making your grounds a lot better.

Does it make the sound with the engine off and the sound system on?

 

[azz00]

RCA's and power are running on different sides of the car. And when the engine is off and the sound system is on there is no noise.

 

[agithegreat]

RCA's out and engine on... nothing through speakers - with that we can assume HU earth tracks.
What headunit have you got??? Let me guess.... pioneer?

 

[azz00]

yeah it is mate

 

[caister]

Are pioneers known for bad earths then?

 

[agithegreat]

Common fault with a few of their models....... Earth tracks in the HU go on a bit of a mad one!
I have a link for fixing it yourself if you want to risk it...... If you can, try a new HU. Then you can be sure that it's the HU!

What exactly model is you HU?

 

[azz00]

Its a 2000MP and yeah the link would be good mate cheers. May aswell have a crack at it myself, but before I do that I will try and get another Headunit.

Cheers mate.

 

[wallop]

If noise is NOT present with engine OFF then it can't be head unit earth track fault....

If noise is NOT present with RCA leads removed whilst playing with engine running it would indicate faulty head unit earth track....

Seems your problem is a poor amplifier earth....

Without RCA leads connected the Amplifier is merely idling & so the current earth is fine...As you connect the RCA leads your now actually asking the Amplifier to work, which requires much more power that your current earth can't support....This is most probably causing your Amplifier to earth through the head unit via the RCA leads....

Because your using a Pioneer head unit I would recommend you address this issue sooner rather than later to avoid possible earth track damage....

 

[agithegreat]

I apologise i missed that he said it was not present when the engine was off

 

[azz00]

Nice one, thanks everyone for the help. I will go sort it asap.

Thanks agahin folks.