It's a three way fully horn loaded speaker, using a corner horn for the bass module, a la Klipschhorn. It has a conventional woofer, a sealed back chamber, with the front horn loaded, where the very rear of the enclosure is an opening partly along the horn path. It must be placed into room corners (or faux corners) so that the walls complete the end part of the horn, thus increasing the effective length and size of the horn mouth, lowering it's effective frequency.
Take a look at the links lovin' posted, particularly the third one, page three, and look at the illustration on the lower right. That's a top-down view of the bass cab as it's intended to be positioned into the room corner. The narrow flattened off apex of the cab closest to the corner is open, firing into the corner.
Since it's derivative of the Klipschorn, the speaker that's been the longest in production in the history of audio, I wouldn't consider it a lunatic design. It is an odd-ball, though, where extreme sensitivity is the overriding design consideration. This is the sort of speaker that the First Watt and SET crowd would aspire to have to use with flea watt amplification. Gotta have extreme speakers to go with the weirdo amplifiers, it's like chocolate and peanut butter, and helps make OCD fun!
