Nees some enclosure advice.

[Gingeriffik]

Going to be builing an enclosure for 2 JL 12W7-3's. As of right now, It's looking like 3.5 box volume(after displacement), tuned to 32hz. Sound good? It is going in an Expedition, and planning on doing a subs up, port back orientation. I could also use some advice on the port. Would like to do a common port, located in the cener of the box, with a larger port area. Calculations show that a 14.5 x 3 port would need to be 27.25" long. Box depth is goin to be between 18-20". When the port hits the back wall and turns, the port width is divided by 2 correct? That is, the port extension into the chamber for each sub will be 1.5" wide.