z110bt distorted output
 

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.

the impedance is correct?

Well the speakers are 4 ohm and the amp is rated down to 2 so I am good there. the input side of the it amp is rated at 10k and I have found nothing on the z110bt to show what it is. I would assume that if it was a reflection issue I would hear distortion across the pre-amp gain range, it seems that when I am hitting the pre-amp harder distorts more. I have the HU pulled and plan on sending it in to Pioneer. One thing I plan on doing is buying a 3.5mm to RCA cable and trying to run the amp off of my ipod just to see if I can hear distortion. I'm not ruling out the amp or cross overs but I have no real way of checking it.

My guess is the speaker terminals are touching the metal in the door. Partially grounded speaker wire.

So I went and bought a 3.5mm to RCA cable and ran the amp inputs off of my Ipod and found that CH1 of the amp was acting up, I checked the connections and swapped terminals and it seemed to follow the amp channel and not the speaker so... I have mailed the amp back for a replacement. We will see when it gets here if that fixes the issue. Now I have to take the dash apart once more to put the HU back in. Thanks for the ideas, I'm not sure that was the only problem but it is the one I am correcting first.