z110bt distorted output

jagodago

So I recently finished installing a z110bt/PDX 4.150 and some SPX pros in my Z. Problem now is the sound becomes very distorted anytime the volume goes above around 10. I have turned the Amp gain all the way down and it does not affect where the distortion come in, I have attempted to check the ground on the HU and well the only place I can really find to put it is on the factory mounts. My next thought is to try the rear outputs from the HU and see if I see the same behavior, or possibly a new interconnect but that doesn't seem likely because the distortion comes in around the same volume level on the HU and seems to be independent of amp gain. Any thoughts would be much appreciated, because I am pretty much out of ideas.