Alternator noise

[Allanagtig]

Hey guys! I have installed a New sound system with an amplifier in the s2, but im having some troubles with alternator noise when i accelerate on the pedal. Ive done everything possible to eliminate any sources from interfering the signal. Im now at a stage where door covers, seats Etc are uninstalled so i could lay every cable hanging free from each other.

Does anyone in here got the same experience, and what did they do to help it ? Please, im struggling 😉

Best regards

[Fat Audi 80]

Do you have the power down one side of the car and speaker / RCA cables on the other?

[Allanagtig]

My S2 is a coupé, so the battery is mounted on the backseats
Every cable for the installation has been seperated and floating through the cabine to eliminate any interference

[Allanagtig]

Correction (on) to (under) the backseats

[Fat Audi 80]

I thought that might be the case if it was a coupe! My next stop would be an ignition suppressor then from one of the car audio suppliers.

It is difficult to say from here without seeing it.

[Allanagtig]

What ive done so far:

Amplifier has it own ground point at the rear seatbelt anchor.
Every cable from the amplifier to the radio has been disconnected and seperated from each other to eliminate interference.
Tried connecting another headunit, but same noise.
Been having one speaker connected at a time, with one set of phonocables to see if that worked.
Switching to other set of phonocables doesnt work either.

any suggestions?

[LHD_Kid]

What ive done so far:

Amplifier has it own ground point at the rear seatbelt anchor.
Every cable from the amplifier to the radio has been disconnected and seperated from each other to eliminate interference.
Tried connecting another headunit, but same noise.
Been having one speaker connected at a time, with one set of phonocables to see if that worked.
Switching to other set of phonocables doesnt work either.

any suggestions?

What distance do you have between the power cables and speaker/ phono wires?

[Jonas_R]

What size power and ground cable do you have?

Is the seat belt anchor raw metal or painted?

Short ground cable, same size or thicker then power cable, good contact with chassis preferably bare metal.

[Allanagtig]

My ampifier is a rockford fosgate. I used the + and - cables that came with it.
So far, ive been having all the cables hanging in free air through the cabine to eliminate any contact or interference. Atleast 10cm from each other.

I grinded the anchor point at the seatbelt before i mounted the ground cable.

[Allanagtig]

The cables that came with the amplifier are 10mm^2 and should be good enough.

The noise is there just when the radio is turned on without the volume turned up, and while engine is idling.