Static in speakers with new head unit

I just bought a '95 325i and the factory radio was not in good shape (No display, etc.) So I bought a Kenwood KDC-358U from Crutchfield to replace it. I got it installed, but now I have static in my speakers. I may of had it before, but didn't notice because I only turned the radio on once. Seems like the rear is worse than the front.



Any thoughts? Just need speakers, or is there a known issue with factory amps and aftermarket head units?

Static in speakers with new head unit