sub box help please

[sfrapper411 0]

Hey everyone I'm looking for a box design I'm trying 2 build a box for my brother as a suprise for when he gets home from iraq I've tried the website calculators and I get more frustrated than I get accomplished please help my max dimensions are 23.5 tall 21 deep and 38 wide he has a 15 inch brahma mk2 looking for ported sub forward port forward I hope my friends in the car audio world can lend me a hand on this one hell be home in a few weeks so time is of the essence thank you you can email me 2 at sfrapper411@hotmail.com appreciate