Steve Deckert (Decware) has been messing with the FE206E. At last years 2003 DecFest we listened to them in 3 different cabinets. The Classic Audio floorstanding bass reflex was the worst (panels were very resonant, bass was loose in general), a small standmount (best to integrate with a sub), and his own HDT (high definition tower) that he sells plans for that reached 40 Hz and did it well.
The HDT is the most complicated non corner horn design I've ever seen, not for the faint hearted woodworker, but he may also offer it pre-cut.
Steve also offers a modded FE206E. But either way this driver isn't meant for bass reflex, transmission lines (my fav), pipes, or especially open baffles (another fav) with it's low Qts.
Two Rivers Audio introduced at the 2003 Midwest Audio Fest a fairly impressive yet inexpensive front loaded option for the FE206E that used a pair of Yamaha servo dual woofer subs, similar to the Oris system.
