Please HELP: Noise Floor - Audible Hiss
So here is my setup:
Stock HU - Factory AMP - Fix 86 - Alpine Amp - Front Speakers (using crossovers) & Sub.
Problem: Even with the gain at 0 and the HU muted, I get a hissing noise coming out the the speakers. I'm using the best RCA cables, all high end equipment. I can't change the factory HU because its the 8.4 and controls other systems in the car.
If i hook up the morels directory to the factory amp, there is no hiss, its only when I run it thru the amp. I've used 2 different amps, both Alpine - PDR-V75 and the Alpine MRV-500.
Don't know what to do. Its not a grounding issue, this is with the engine off, there is a loud hiss and if I turn up the gain it gets worse. My fear is that there is nothing i can do here and its the stock HU.