Yes as long as your rear speakers are conencted along with your other car speakers it will have a range you set (High Pass Filter) you can set to send any sound levels of a certain level straight to your subs. You can also set the frequency of the subs. You have 2 controls one for your internal speakers and one for your subs along with the choice to turn the subs off completely.
It takes A LOT of time to fine tune your system to your liking so be prepared to spend countless hours having fun getting your neighbors pissed with the speakers turned up =)