Starting out to say nice selection of sub!:T (I'm planning on purchasing from IST soon as well)
But over to your question I would recommend building one yourself if at all possible. A good calculator I found was at the link below: (there is also a link on that page that directs back to another HPF problem from a fellow shackster which I also posted below)
http://www.subwoofer-builder.com/subsaver.htm
http://www.hometheatershack.com/for...-pass-filters/19570-need-subsonic-filter.html
Good Luck!
But over to your question I would recommend building one yourself if at all possible. A good calculator I found was at the link below: (there is also a link on that page that directs back to another HPF problem from a fellow shackster which I also posted below)
http://www.subwoofer-builder.com/subsaver.htm
http://www.hometheatershack.com/for...-pass-filters/19570-need-subsonic-filter.html
Good Luck!