Ratcheer

whose most popular speak, the Abby, uses the FE166E in a TQWT.

Looking at the parameters of the FE166E, I would not have thought it applicable to this load (it looks like a backhorn driver), but he has sold these (under duress!) to no less a light in purist audio than Nelson Pass.

Evidently they work okay in this load, and I definitely think that they are the potentially best single speaker in the current Fostex line.

Get a pair (you couldn't be sorry), and experiment. You will surely get at least good sound, and as you develop, excellent.  Post back with developments, as you become a budding single-driver guru.

Don't forget to check back in with developments,

Poinz