@riverdinaudio, agree about the Maggie ribbon tweeter. I have a pair of Tympani T-IVa's, which contain it. I never though of using it in place of the ribbon tweeter in the LFT-8b, as that ribbon is used only for the top octave. When I get the time, I'm gonna place the T-IVa m/t panels beside the LFT-8b panels, compare the two tweeters. Thanks for the idea!
There are a group of guys on the Planar Speaker Asylum Forum who had removed the midrange driver from the T-IVa, replacing it with multiple NEO8 drivers (seven, iirc). Haven't heard them myself, but reports are very positive.
I failed to mention it above, but the GT Audio Works sub is nothing more than the GR Research/Rythmik OB/Dipole Sub kit installed in their own H-frame, not visa versa. Credit where credit is due! The sub came from the fertile mind of GRR's Danny Richie, a long-time proponent of OB loudspeakers and subs. When he learned of Rythmik Audio Brian Ding's new servo-feedback sub system, he thought mating it with an OB woofer (which are designed specifically for that application, different from those designed for non-OB use) would create a new SOTA sub/woofer, and got to work on the design.
The sub uses the Rythmik A370 plate amp, into which Brian Ding installs a dipole cancellation-compensation network (a simple single-pole/1st-order low-pass filter). Danny designed the woofer, which is the Rythmik 12" paper cone woofer optimized for OB usage.