I'm sure they sound spectacular, but at 37k, I'll remain happy with my bi-amped K-horns !!!!
All New Songer Audio FIELD-COIL Speakers : Taking Field-Coil Speakers To A New Level !
They are making their Field-Coil speaker drivers like nobody else !
https://songeraudio.com/technology
More info here
https://www.whatsbestforum.com/threads/an-introduction-from-songer-audio.36021/