I finally finished the folded horn subwoofer build and they actually brought the house down at the Electrocution II Festival last Sat. During one of znuh's sets he brought the bass and I sent it right back causing the ceiling tile above post_future to disintegrate and rain down on her, sorry about that :)
Not bad for a 4x10" sub running at 600W. I'll put them up against any pair of 18"s anyday. I'll be posting some pictures of the build pretty soon.
I'll post more about EF-II pretty soon (including pictures)