My old Paradigm PDR10 has a 37L enclosure with a 3"dia port that is 7" long. That is a 38.5hz tuning. So then I decided to find out what the highly regarded PW2200 was tuned to. After stopping by my local dealer only to find out they were sold out. So after some emails I was able to get someone else to measure for me, 5" dia port that is 16" long. With an 83L enclosured that is a 30hz tuning. I was just a little bit surprised by both. They both have some stuffing in them though, so how much that would lower the tuning frequency I don't know.