Wayne,
I'm intrigued by your Pi speakers. I have built about 9 different subs and mains over the last 2-3 years but I'm not really all that satisfied with most of them for one reason or another. Some were really complicated and some rather simple. One of the projects I thought turned out well were my Table Tubas. I used the Eminence HL10-C's in them and they really are surprising. I was looking for a pair of mains that might be a good match for them. I have built a pair of home brew "El Cheapo Bell Grande" line arrays with Foster blow out mids and a Dayton ND20 array and an active crossover. Fiddling with it for a year on and off. I don't think it can ever be done. Everytime I change source material I have to re- equalize. I'm wearing out my Ultracurve...
To switch gears I thought about a horn tweeter maybe a BMS 4540 / DSS pro 90 and a mid horn of yours ? Any ideas ? I'm also trying to go to a passive crossover.
I would like to hear what you may suggest. I do like it loud once in a while and I don't pretend to be someone who hears the difference between speaker cables. I have a big basement room 14' by 35' treated with membrane traps. My hearing doesn't seem to extend beyond 14Khz per the audiologist.