So I have a problem I am getting ready to make a ported box for my BTL 12 that is fully loaded. my big question is how do I tune my port to 32hz? the dimensions are 18w x 14h x 20d which comes out to be 2.20812 cubic feet. can I please get some help and advice I used a slot port calc but I guess the port length looked funny to me. Subwoofer Enclosure Calculators, Fraction to Decimal, Parallel, Series, Port Length and Volume Calculators Thank you