There is a converter you can buy from Best Buy that will turn normal speaker wires into audio cable jacks (RCAs) you can tap into the wires up front or in the back near the rear speakers. That will give you a low input to your subs and you ll be good. If you tap into the rear speaker wires it will also be controlled with your fade button, but so will your rear speakers.

As for the remote power supply not sure what you mean