Is there an advantage to a PR over a port? I will be making some MTM's with 6.5" drivers soon and wanted to know which is better. I would like for them to play as low as poss. The towers can be anywhere from 1.8 ft^3 to 3.0 ft^3 and the center .75 ft^3 to 1.0 ft^3. If I design the speakers (WinISD) with a nice flat frequency response and a port to have an f3 of 40 hZ, what would be the advantage of a PR? Will it play louder or go lower? From what I can tell it looks like the PR wouldn't be as good. I guess PR's really start to shine when used in small sub boxes.