Guess he didn't know what to call this misleading thread. I would get a better HU.It doesnt sound like its actually mechanically bottoming out since op is not even playing low. Sounds like a weak dirty signal causing an overload of distortion. Had an issue like that with a guy swapping out a kenwood single din for a power acoustik double din and he lost soo much output and his sub sounded wierd when pushed.
I don't get why people wanna replace everything else in the car/SUV/truck and leave the HU stock.