I find that using bass boost isnt worth it. It just introduces clipping faster and the boost is usually centered around a certain frequency, like 40 or 45hz. So just those frequencies will be boosted not all of the low frequencies. You best bet is to turn the bass boost all the way off, set the gain correctly, set your HU to flat and just turn the subwoofer output up on the HU when you want more bass. Best way to go about doing it.