Originally Posted by
KDW4Him
Technically speaking there is not "extra" bass going to the subwoofer, it's always been there. What this does is keeps the bass out of the door speakers. This will appear as more to the subwoofer to the ear.
BUT, by keeping the bass out of the door speakers, we tend to run the system louder - so more bass IS going out the back of the amp - just less of it gets to the door speakers - so there easily COULD be more bass to the rear speakers.