[Beisofmarko]

I Have alternator whine that raises with the engine rpm's.
I've been trying to do some troubleshooting myself and found out
that it goes away when i unplug RCA cables that are going from the
first amp (match pp82dsp) to second amp (audio system X-330.2).

The RCA cables i have are supposed to be "better" quality ones, bought from car audio shop.
They were routed next to some amp channel wiring and i tried to separate
them and hold RCA's in the air to make sure they are not picking anything
from other cables but didn't seem to help, the whine is there when they are plugged.

Any tips how i should proceed?
Thanks!

[Emilime75]

Alternator whine is, in most cases, a grounding issue. Either from a poor ground connection, or a ground loop. The reason it goes away when you unplug the RCAs is because there is a disparity in ground potential between the 2 devices that are connected by those RCAs, and they are trying to balance out.

Interference is still a possibility, but grounds are usually the culprit. How are your components wired? Do both of your amps connect to a single ground point? Have you tried a different set of RCAs? Photos of your setup may help.

[Beisofmarko]

Originally Posted by Emilime75

Alternator whine is, in most cases, a grounding issue. Either from a poor ground connection, or a ground loop. The reason it goes away when you unplug the RCAs is because there is a disparity in ground potential between the 2 devices that are connected by those RCAs, and they are trying to balance out.

Interference is still a possibility, but grounds are usually the culprit. How are your components wired? Do both of your amps connect to a single ground point? Have you tried a different set of RCAs? Photos of your setup may help.

Thanks for the reply! been bit busy with other stuff so took a while to respond.

I have not tested YET with different set of RCAs because i thought problem should be somewhere else
as the ones i bought should be really high quality ones, but i'll get my hands on different ones and see if they help any, not a problem

I have different ground points for both amps, i thought it was best to separate all the possible cables from eachother?
Plus second ground cable was not long enough to run same to same ground point as first amp.
Here is some photos you requested if it helps any:

Technic harness from HU and speakers cables are routed under side panels to trunk,
Harness connects to amp 1 (match pp82dsp) and its grounded to some sort of factory
ground point at wheel well location.


Amp 2 is grounded to different location which might look sketchy?
I actually took it off later and sanded whole contact surface better but didn't
help at all.


Does anything seem wierd here?
Thanks!

[DavidZ]

Every instance of alternator whine I've experienced on multiple cars I eventually traced down to a speaker wire being too close to a heavy gauge power or ground wire. Doesn't explain why your whine goes away when you unplug your RCAs, but it wouldn't hurt to check?
Are you getting the whine from all speakers?

Edit: oh, look at that, two of your speaker wires go right under your power cables. I'd route those speaker wires to the right and above the amp, away from the power cables.

[Emilime75]

In most cases, like 99% of them, cables crossing perpendicular to each other are ok, it is when they travel parallel to each other when issues arise.

[DavidZ]

I guess I'm the 1% then. Just reporting my experiences which had absolutely nothing to do with grounding but with signal wires' proximity to power cables. I also think it's a good idea to keep signal wires away from power cables whenever possible and crossing them at 90 degrees if there's no other option.