I am planning to build a dual 12" subwoofer enclosure to fit under the back bench seat in my truck. The subs I have are 2 Rockford Fosgate P3's, the need 1 cu. ft. chambers each. I have three questions: 1- space is limited under the seat, in order to have the most room for the chambers which would be more affective upfiring into the seats or downfiring into the floor pan? Question 2- which configuration tipically sounds better in a truck, upfiring or downfiring? Question 3- whether I am upfiring or downfiring how much space is best between the sub and the bottom or the seat or the sub and the floor?