Hopefully someone can help me out on here!

I just changed decks from a JVC KW-AVX830 to a JVC KW-XR810, and right from the start noticed that when changing the 'sub level' setting, there's an audible humming noise that comes from my subwoofers. This occurs as soon as you turn it up from 0, and does not get any louder by increasing the sub level, but is constant. I had no such problems with the AVX830, and nothing else in the car was changed with the new install. RCA's, remote + power are all in the same spots.

Also, it sounds like i can hear the electronics of the car (window motors, turn signals, etc.) through the subs as well. Is this a signal issue, with the rca's picking up some sort of interferance?

The install was done at futureshop (to maintain my warranty) so if worse comes to worse it'll go back there, but if anyone has any suggestions please do tell!