Rick, thanks so much for sharing your creations on this forum--you build beautiful speakers. I know there has been a lot of discussion on mid-range drivers, and I'm curious if you have tried the new Eton 3-inch mid-range? I know you have had reservations on Eton drivers in the past, primarily due to their motor structures in woofer applications, I believe. I don't think these reservations would apply to a dedicated mid-range application, however.
It seems like a 3 inch cone driver would be ideal for the 500 to 3,500 hz frequency range, perhaps coupled with an eight-inch woofer or dual seven inch woofers? The SB acoustics ceramic mid-range looks fantastic and is much cheaper, but the Eton has two key advantages: 3.5 db of extra sensitivity (extremely important, in my opinion) and a much milder cone resonance at high frequencies (simplifies crossover design, always a good idea).
Food for thought for anyone considering a new design: i suspect these drivers could be an outstanding option to consider!