engine wine know how its there but can't get rid of
First of all I have searched the forums tried every possible solution I have found on this forum with no luck so here I go.
I have a very common engine wine noise problem.
first of all power wires & rca cables are separated
all computer cables are separated from power and speaker & rca cables
using a head unit aux in (pioneer DEH-P960MP head unit) for computer
external SoundBlaster soundcard
1 4ch amp
1 mono amp
300 watt inverter
If I do not ground any part of the computer I.E. The case,power supply, motherboard etc I get a loud "buzzing" interference noise. At that point I do not hear any "engine wine" noise that is consistent with the rpm's of the engine. if I ground the case,motherboard,power supply or even all of them the "buzzing" noise goes away but then comes the "engine wine" noise.
(tried single & multiple grounds to different points on the computer parts and different grounding points in the car.
with sizes from 14g to 4 ga wire but does not help)
also tried ground loop isolator by the soundcard and even going to the amps with no luck.
I am not sure how to get rid of the engine wine noise.
I know where its coming from because when I ground the case its starts then, but I do not know how to get rid of the wine.