I have a 1995 Ext. Cab F150. I have completely removed the back seat so space isnt really an issue. Im not sure what size box to make, and if it should be sealed or ported and which was to face the sub. Ive been told Sealed and Downfire, and RE recommended a 2.1cu. box. Im looking for loud and LOW. Sub is an RE XXX 15" D2 on a RF T20001bd, so should be ~2000RMS. Anyone have any input on this?