I found these specs ~4 cuft net tuned to 32 Hz 16" h x 40" w x 20" d Port is 14.5" x 4", 30" long. To get 30", you make the side port wall so it extends into the box until it is 4" from the back wall, then add a piece 10" long running parallel to the back wall. Box is .75" thick, except the baffle is 1.5" thick. I made this in sketch up to specs I wanted to see if it looked right. besides the port being off the ground i think it is. I am new to building sub woofer boxes so any help is appreciated