The driver clearly is temperamental (in other words peaks ). However, it sounds WAY clearer than the fostexes (16X series) and has the nice midrange that my Stephens trusonics has, but even better detail. I can see a Lowther playing a role in my next speaker project (though probbaly not full range). My guess is that in the 100-150 to 3500 range these are great! There are some peaks that still need to be tamed even in that range. Overall, a phenomenal driver!

BTW, the driver sounded great in Bob Brines' box & with the circuit used. Kudos to Bob for actually taking Martin's work & commercializing it in a value offering. The Lowther sounded great in that box, with reasonable bass (though you will need a sub for true extension, and proably a tweeter). Overall a wonderful driver and a very good implementation by Bob Brines!
-akhilesh