chadlogan112

No they do not run together. Whine stays steady regardless of volume increase.

843de

Here's something to try, unplug the antenna adapter from the head unit and see if the whine goes away, I've heard of aftermarket head units picking up an interference whine through the antenna.

If the whine goes away, there are antenna noise attenuators available which plug between the antenna lead and the head unit.

EcotecRacer

First test play system without car running.. any noise?
Next have a AVR test done but please read following in depth
I would like to mention and stress to you the following.

Newer vehicles today employ *Avalanche Diodes* and many automotive repair facilities cannot measure the diode pack correctly for nominal operation using standard diode check methods.

If the shop has updated testing equipment such as Midtronics testing tools, or a scanner oscilloscope then the square wave form can be captured for ripple(s) which then can determine if any of the eight diode packs are damaged.

Older testing equipment will pass Avalanche diodes almost all the time, due to their low voltage output.

Which then leads you down the wrong path. Remember, you can have 5 of the 8 packs damaged or fewer, and the vehicle will continue to operate as the battery acts like a filter and will absorb some of the unrectified or leaking AC voltage.

Do not let Jimmy Joe Smith who has no electrical trouble shooting do the test. You want a qualified professional to capture and display the square wave for you so as you can see for yourself, which should have almost no ripple in the wave form.

I will address how to trouble shoot the other Q later

Putter

I will be following this thread closely. I also have the dreaded whine. My amps are mounted in the rear (a 2-channel amp and a 4-channel amp)
I have tried the following:

1) Re-routed RCA cables (no change)
2) Replaced all RCA cables with much higher quality ones...routed 2 different ways (no change)
3) Grounded all RCA outputs on rear of headunit (no change)
4) Replaced BOTH amps with new ones from another brand (no change)

The only thing left for me might be the headunit, but because of $$, I am putting that one off until it's the last option!

EcotecRacer

Please try both test i mentioned above and let me know results
Also for you have any shop with a bench test headunit run rca directly toyour amps and see what happens

chadlogan112

Update: yesterday I had a family member listen for whine. And asked him to let me know if it lessened as I lifted the rear amp tray, as it raised 6in, the whine disappeared completely. So my amps are just getting interference with the battery it seems. So I'll just relocate them to the seat backs I suppose.

EcotecRacer

Thats a sign of a bad ground
If one ground sees a higher resistance than another that induces noise

chadlogan112

I don't see how though, each component is grounded to the same location. My buddy that's an electrical engineer says be thinks amps have little wound coils inside that are supposed to be coated, but after a while it burns off and will absorb those rf signals?

Breadfan

I agree with your buddy. Induction interference can occur in fully grounded applications. This is going under the assumption that you have clean voltage to it and secure consistent ground. I'm not sure of your placement, but you could try flipping the amp around 180 degrees to try to distance the coils from the battery somewhat.

EcotecRacer

You say to same location but you added a ground
Your electrical buddy should know rf interference changes with volume....as ohm change dc resistance changes, thus the square wave ripple increases and frequency of noise changes
Theres old trick of using a light bulb to show this



Are you sure you have alternator whine and not another interference?
I still suggest testing each ground for resistance if any vary there is your issue


Fyi an example is if you upgrade battery to amp and same for amp to ground but leave all other power and ground are factory this causes ground loop aka noise