Sounds like a problem with the EQ to me. Which one are you using?
1999 Buick Park Ave Ultra
Head Unit: JVC KWHDR720
EQ: Audiocontrol EQL
Front Stage: Hybrid Audio Technologies Imagine 5.25 mids, Morel Maximo tweets
Sub Stage: Boston G3 10", 0.5 cu ft sealed
Amp: PPI Phantom 900.4
Rear Fill: Boston SE953 6X9's
Did the problem start when you added the eq?
Update: I've managed to get it somewhat work.
- Added ground loop isolators.
- Separate grounds for EQ and HU
- Beefier wiring (Was using some crappy thin wire before)
- Power directly from my distribution block to EQ
- RCA's moved to right side of car from center, and away from remote wire
- Grounded RCA's at amp and HU
- Still a slight hiss, but not noticeable when engine is on. - Definitely not my gain, as the gain is set at the lowest and is still getting plenty loud at 15 volume on HU
- Whine introduced when EQ input goes above 1/4.
I wonder what fxed a large portion of this no matter what I do it doesn't change
H/U Clarion nx702
2 sets of massive ck6x off a md42
1 set of PPI nt.2 super tweets of a Massive bx2
2 re mx 12" subs in a STARMOUNTAIN enclosure powered by 2 MD3D amps