new h/u install - AMPLIFIER NOISE - HELP - ahhhhh

[lousdad]

I recently replaced my kenwood ddx8019 h/u with another kenwood unit (dnx8120) with navigation. After wiring it up, I have alternator noise from all 4 speakers in the car. I never experienced any noise with the other model or any previous set-ups in the past. I switched out both the RCA harness and the main wiring harness - still have noise. Noise is not coming from the radio antenna either. I isolated the amp and RCA cables and no noise from them according to a crutchfield article I found online. My power / signal wires and RCAs run down opposite sides of the car. I also checked the ground for the amps and it good connection to bare metal within 12" of the amps. The gains on the amps are also set at less than half.

Here is my installation setup:
kenwood h/u
4x50 amp to 4 MB quart Q separates
1 ch amp to alpine x sub
power and ground for both amps both run though a distribution block (on top of a 5 farad cap)

I have read that I may need to ground the h/u pre-out jacks??? the radio chassis itself??? (these seem odd to me as I never had to do this before) or install an alternator noise filter???

HELP!! any ideas???

[introvert]

1. Make sure to avoid any power sources along the length of the RCA
2. Double/triple check both (amp too) ends of the grounds - Make sure they're not loose

Question: Are the RCA terminal surrounds exposed in the rear of the deck and are they touching any part of the car's chassis or loose cables when you have everything back in?

[lousdad]

Thanks, I grounded the h/u directly to the firewall, covered the RCAs, re-stripped and soldiered the acc, power and ground and about 70% of the noise is gone. I'll probably get a noise filter to make up for the rest.