You are given the options of -subwoofer(not the ones behind the seats), bass, and treble. Also fade front to back( doesn't apply to our setup) as well as left/right. You can also BUY an external module that you hook up and do a sonic test of the car's cabin, and the you can adjust the parameters from this device. We didn't buy that unit, we did the "Biggest Bang for Your Buck" door speaker mod. It really is amazing the difference that mod makes on the whole sound from the factory amp/speakers. Essentially you're creating a low pass filter for the door speakers to redirect more of the bass information to the subs where that energy belongs. I was stunned after doing this mod, that the Infinity designers didn't catch such a simple fix for their sound system.