Why does it whine?

[Keanan]

In my 86 325es the speakers make a whining noise. The volume/pitch of this noise varies with engine RPM. Also when the ipod is plugged in there is a steady quiet noise (white noise, fuzz).
This is the stereo set up:

Head unit - Blaupunkt Hamburg MP57, with Bluetooth, USB and ipod input
Amp 1 - Blaupunkt PCA465 Amp (4 x 130W) Running the four speakers.
Speakers - Blaupunkt Vc540, 5.25" Components, speakers are in stock locations, crossovers are located under dash in front and under parcel shelf in rear.
Amp 2 - Blaupunkt PCA1300, 1 x 300W, Running 10" Infinity subwoofer in trunk
Power and ground cables for amps are 4 gauge coming off the battery and grounded to the wall between the trunk and back seat, speaker & sub wire is 14 gauge.
RCA cables, front speaker wires and remote signal wire are all routed under center console and carpet on top of trans tunnel.

Back to the noise. The noise that occurs when the ipod is plugged in is a low buzz, it happens even if the stereo and vehicle are off.
When the stereo is on and the vehicle is running there is a whining/whistling sounding noise that varies with engine RPM.

My questions:
Why does it make this noise? Is it cause I don't listen to country music? Could there be to much resistance in a ground or other connection? Do I need a capacitor? Do I have the RCA and speaker cables routed through the wrong spot? Is this just user error?
If anyone has any suggestions on how to eliminate this noise I would greatly appreciate it.

Pictures below show how amps are set up in trunk.









Thanks,

- Keanan

[TexasTerp]

Your cables are picking up interference because you have them routed along the transmission tunnel. Where are your front crossovers located exactly? if your signal wires are too close to the firewall you're picking up the engine whine from there as well. Also How do you have your Ipod setup? the cable is probably picking up extra energy from surrounding wires.

More pics of the interior setup would be helpful

[M-technik-3]

From what I have been told it's RCA wires on one side and power on the opposite side of the car. I am not an audio expert by any means.

[dude8383]

shit, i may have to re-route my wires because im no audio expert :(

i have the same freakin whine!

[Schnitzer318is]

RCA's/speakers wires down the driver's side of the car... and power wires down the passenger side. Since you own a BMW with trunk battery most likely the power wires won't be an issue, but your might be picking up noise in the middle of the car.

Also some RCA's are directional (thanks luke for that bit of info)... that could be a cause. Also all your wires are all-ova-tha-place in the trunk. That's never really that good to do either :)

Edit: took another look at the pics, and the trunk wires aren't that bad... I'd check the other suggestions first.

[Keanan]

Could having the RCA's and speaker wires on the trans tunnel really be causing all the interference? I thought it would be a decent place cause it is away from the main power cable on the passenger side and any other wiring on the drivers side, I can re-route them if needed.

For the crossovers in front the drivers side is up near the ABS module and the passenger side is tucked behind the OBC. Rears are mounted in the trunk above the amps.

Ipod and USB inputs run behind the OBC and down into the storage spot behind the ashtray.

Power/Ground wires are all in the trunk. They run from the battery up the right side of the trunk to the amps. Head unit receives power from stock wiring. The remote wire for the amps runs down the trans tunnel parallel to the RCA's and speaker wire. I guess that could be causing some interference.

[dude8383]

http://www.diymobileaudio.com/forum/diy-mobile-audio/10374-alternator-whine-hu-powered-off.html