Pushing for thinner diaphragm, better material and stronger magnet, lighter and efficient overall design shouldn't be underestimated. Not every 20khz capable driver is same. I find ''technicalities'' proper term.

How much of Susvara's, LCD5's, electrostat's qualities come from acoustic design vs technology ? Susvara doesn't even have fancy CSD plot so i don't know how much acoustic treatment it got. We know how Audeze tried hard to get consistency with their thin planar development. A big headache for them, must yield some results in terms of ''technicalities''.