Very interesting! Like the passive topology allowing your choice of amplifiers.
Response is relatively flat, but mid-band efficiency is quite low (84dB), meaning they will need some decent power (high current, actually). They are limited to 98dB SPL max. Impedance also goes low (<3Ω) at HF, meaning many amps would not do well with them. I'm guessing a 60V Cherry STM would drive them nicely, maybe even the 48V version. Has anyone here heard these speakers?