one of 2 ways. divide the box by 3 and figure one port for each "box" or minus the "braces" from the overall port area and figure it as one port.wowzers. Looks Great.
i have a few Q's tho. Do you have to take in acount that its 3 small ports in one? Or does the box "see" it as just one port? So i guess my real question is, how do you figure tuneing? for 3 ports or 1(just minus wood)?