Wonder how low the tweeters go before rolling off to the 15" sub? You don't see that many 15" midrange drivers.
I would guess the crossover is set high and the gain (volume level) will be low. Raise the woofer gain and the sound will be fatter, boomier with some heaviness and plum-iness. Baritone male voice will start to sound too thick and rich and speech clarity will begin to be affected. The open baffle design will compensate for some of the fat bass. The speaker will sound acceptable in some rooms, especially for $3000, but will be a disaster in others.
I have heard Tekton Brilliance speakers, which were also $3000 pr when released around 2017, and the one of the early Emerald Physics speakers with a 12" open baffle driver, neither handled the tweeter/woofer crossover region very well but they made some sort of music that some people liked.
REL's John Hunter has a good video explaining woofer properties and speed.
https://www.youtube.com/watch?v=nt3kYxInC4o