And have you tried them in a blh (back loaded horn)? I had some vintage phillips fullrangers (late 60's early 70's) , and they sound pretty dang thin , congested and not too dynamic in their bass reflex boxes.
So I decided to make some blh's (bk-16's cabs of of the madisound site). I wanted to try the set/ single driver/blh thing out and see if I would want to persue it further.
Well results were great , and I placed an order for some fostex fe166's. I will place them in the same cabs for now, but I plan to put them in a much differnt cabs, ala' something similar to cain-cain I-Ben.
I also have been very curious to trying some pi speakers out. I wil try some 2pi's 1st then jump up form there is I impressed.
If you are decent with a table saw , try making the recommened fostex blh for your type of speaker, giev it a shot, wouldn't hurt. You might be very surprised.
Good luck,,,
chris