bad hum on speakers

I just installed an audiocontrol dqs. Everything went well except now I have an annoying hum/buzz noise coming through the one channel(used the center channel for a set of waveguides). I've tried grounding the rca shields but no luck. Tried the ground point at the ground dist. block, the ground on a capacitor, as well as metal in the vehicle. The dqs replaced a audiocontrol eqs(which there was not a bit of noise). I'm assuming since the upgrade is digital, I don't know. Anybody have any thoughts what this might be and/or what I can do? Thx

Just wanted to add, only have the noise while the vehicle is running. Ignition off, its crystal clear.

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