I just got a 15" Audioque hdc3 and I am going to get all new everything to run with that. Im guessing the box would be the next step. I have a 2003 ford explorer sport xlt and it has a relatively big area for a box. I am lost as to what size ported box to use and what frequency to have it be at. I'm looking for loud and and still being able to hit lows. What size box should I have made? All help is greatly appreciated.