Most tweeters will be in serious breakup mode from about 20KHz upwards..

Soft domes will start at about 13KHz, but it's fairly innocuous as they are soft & it is damped. Aluminium will start complaining in a nasty way at about 16KHz, Titanium approximately 19KHz...

But Beryllium is way out there at 27KHz 2425_animado.gif