im looking to build a box for 6 15" re xxx. its either going in an envoy or a trail blazer, but i want subs up, port back. i think right around 25 cubes, but im not sure about that, or port size. i would like to tune it to about 30hz, but would also like to be able to change out the port to something higher for when i go to a comp. i like the idea of having another baffle on top of the speakers for the flush look.
any ideas or input would be great. im open to suggestions as this is a loose idea right now.