i got this design from 80 and i know he is a busy guy so this is why i am posting it here. i originally wanted to do a 4th order bandpass for two 18" bl's but he gave me a 6th order bandpass. which is sweet but i dont want to cut the whole wall of my truck out. i just want to make a whole about 22x22 for the single port. does anyone know how i can use this same box, but maybe seal the two 8" ports and have a single square port coming out the front? and how would i make the port protrude out of the box maybe 6" so it actually is in the cab a little? man i wish i had a box building program!!! lol.