ok, when you are making a folded port how much space at the exit should you leave from the port wall? currently i have had to add a few inches of port so that it doesnt end directly at the wall which is ok i guess since that lowers the tuning. i am in the process of trying to finish modeling the box in Sketchup but im running into problems since im not sure how to end a port for maximum performance. im attaching my sketchup file of the incomplete box so hopefully someone can give me some help.

actually i cant attach them. if anyone can give me some help ill email them the file or something.