the head unit is a alpine cde 9873 hooked up to two pairs or 4 ohm speakers was working fine then it went totaly distorted and now if the volume is above 17 it distorts but below that its fine like this for all the speakers and when lisening to the radio or cd

 

sounds like someone cranked the bass on you.

 

nope it was working fine and then it started to destort and not just a little it sounds like when you turn to a tv channel with snow

 

I had that problem with an old Alpine deck, tunred it up past 20 and it just sounded like garbage. I never did figure out what was wrong because I just got a replacement deck under warranty. If you still have warranty I'd recommend taking it back to where you bought it.