Help, Distortion in new install
 

So I'm getting hella' distortion from these subs (ill explain the quality reason later lol) I just threw two memphis reference series 12's in my crew cab powered by a rockford T500d. When going to set gains/tune a bit it becomes 90% distortion when the gain is at about 3-4 (around a 3rd) of the way up if that. I had headunit settings are all at a neutral point.

now for the Memphis Reference series 12's, they've been laying around for long as I can remember and wanted to just throw a little somthing in the truck until I get my actual set up going. Still need to finish running wire, dampening etc. Before throwing in the big boys

I'm not a completely new to car audio, just been a few years since done any so now I'm playing catch up

any help would be much appreciated

Thanks,
Stephen S.