thanks for the response man, my problem is that I think not having nearly enough port area for what i'm tuned at is causing my sub to unload below tuning before it should, my friend's box is tuned to 30hz and he can play 22hz with ease, but his box has lots of port area. I know i'm tuned to 36hz because i've ran lots of test tones through my sub and it moves the least at 36hz. Just as an example, box A is 4 cubic feet tuned to 36hz with 8 sqin of port per cubic foot, box B is also 4 cubic feet tuned to 36hz but with 14sqin of port per cubic foot, will the sub unload more below tuning in box A or box B?