If so, what material did you use for the membrane? How did you calculate your measurements? I've never attempted this before, but am interested in trying...

 

I'm only asking because of the buick in this article...

http://www.termpro.com/showcars/index.asp?Page=20

The article doesn't go into detail, but that buick had two 15" subs in an aperiodic membrane enclosure. I was told about it prob abt four yrs ago, and never had the ***** to try to build the enclosure. The only opinions I get on it, are how hard it is to do, and you'll never get it perfect. That makes me want to try...