I was thinking about buying some bass shakers for the seats, which need to be driven by the head unit (or amp). I am going to get a four channel amp to run off of a Kenwood 7015 head unit. Is it possible to use all the pre-outs to plug into my amp to power my speakers, and then power my bass shakers via the rear powered outputs from the head unit?

 

I think it would work, but you may want more power, maybe two of the externally amped channels to power the bass shakers. Good luck.