You have given quite a lot of useful information on these drivers. The DIY press usually ignores the subject of piezos. I have gotten a great deal of information on what I considered a "hidden art" before these posts. Your posts have taken me a lot further in understanding these interesting drivers.

Piezos are a natural for the DIYer. They are simple, cheap, and rugged, have a wide frequency response and don't require a crossover. What’s not to like?

Please post the values of the inductor for the woofer on the 800Hz driver (when you get you system fine tuned). Let us know when you get any more interesting data.

Dave