High pitch noise

[fordpride]

Hi guys! I'm new to the forum and need some help. Here's what I've got. I have a high pitch noise from the speaker when vol. on HU is at 1 it doesn't change with engine RPM's or HU vol. if I turn the vol. up I can't hear it anymore but it's driving me nuts.

HU alpine 143bt

Components RF prime series

Subs RF r2d2-12 x2

Amps RF r500.1 subs

RF R300.4 doors

RF R150.2 kicks

Mall wiring is sky high 0 gauge to mini bus bars 4 gauge to amps. My ground from the bus bar is going to the frame(37" long) 14 gauge to doors.

Big 3 well 4 I have one ground going to the factor location and one to the frame

[fordpride]

[Skullz]

Does it make the same noise with the engine running and shut off, or just running?

Double and triple check all connections especially grounds.

I like to bench test my amplifiers to make 100% certain they do not have an issue prior to installation.

[fordpride]

Only when running

Amp have been pulled and bench tested with no issues.

I have also disconnected the speakers and connected a test speaker to the amps and the noise is still there.

Hooked my iPhone directly to the amp with the same noise.

Amps are daisy chained

Truck is a 2012 RAM

[never knows best]

here is some useful info-

http://www.termpro.com/asp/pubs.asp?ID=121

[fordpride]

Can noise be introduced through the power wire ?

Reason I ask is my wire follows the factory harness from under the hood, down the frame rail up through the floor

[SIDE SHOW]

Is it coming out of both front speakers or just one side? swap the rca's at the amp and see if the noise changes sides or stops

[fordpride]

It's coming out of all 4 components up front, rear fill speakers and subs

[fordpride]

If I turn my amps all the way down it goes away but once I move the gain pass 1/8 turn it comes back

[never knows best]

sounds like a noise floor issue. here is another link that will help-

http://www.crutchfield.com/S-pfnl4dFNbqT/learn/learningcenter/car/amplifiers_noise.html