At this point we are no longer upgrading the system but are embarking on an actual redesign.

I agree with you there. I actually tried the 093 swap in a Jubal. And you know it sounded decent measured like hell. Network needed a redesign as you point out. Did a real hack job and used the 1/3 octave EQ to iron it out. Sounded better measured very good. Sounded better and more closely matched my mains. Left it there until I got my 801C coax center built. It is a viable swap but not a simple drop in. There are many driver combinations that JBL never tried because some flat out don't work or they are way to expensive to manufacture and sell mass market or the driver combinations were not available depending on the vintage. As home builders we are making a pair so we have the option to try almost anything reguardless of what the final cost may be. Lets hope we get lucky and find good combinations that do work well together. Now can our home brewed creations compete with the clasics?? That's a tuff one and without the real thing to go against?? I would like to think they can but it's kind of a arogant statement to make and at least for me I steal/copy and borrow as much as I can from the original designs. I guess as long as we are happy that's what matters. We may end up with a real winners and it's too much fun not to try.

Rob