I will start by saying that most of my experience with subs and sub building has only been in a car. So I need some good HT advice. My equipment, Denon 3808ci running my old Paradigm monitor 7's, cc350, and monitor 3's v3 rear. Had a ps1000 sub which I gave to my Dad because it wasn't doing it for the room. The room is large, 20' x 24' with a 15' ceiling. Want to use what I already have plus the cost of wood. I have two Digital Designs 1010 woofers (which are not their massive spl woofers) and a Paradigm Ref. 1500w Ultra D class amplifier. When I had the woofers in my car the box was designed for spl, both in the same space with a large port area and tuned to 35hz. Will designing a box with less port area reduce spl and increase SQ? Do the woofers need to be divided or can I pair in one enclosure? Does tuning to 25hz sound about right? I know the room needs more than I am willing to give it, but I also know if I build this box right it will be a lot better than it was.