High power, high sensitivity tweeter at 20Khz

Piezos at 20 kHz can’t handle any more power than a good 1” exit/2”coil driver. Full brunt of a 30 watt amplifier at 22 kHz got a KSN1005 to start smoking. A good quality compression driver will take it. Go to a 2” and give it 60+ watts. But a 2” will roll off more than a 1”, so I doubt it buys anything above audio.
 
Piezos at 20 kHz can’t handle any more power than a good 1” exit/2”coil driver. Full brunt of a 30 watt amplifier at 22 kHz got a KSN1005 to start smoking. A good quality compression driver will take it. Go to a 2” and give it 60+ watts. But a 2” will roll off more than a 1”, so I doubt it buys anything above audio.
I'm not suggesting Parts Express bender disk tweeters but something made by a company that deals in serious transducers and actuators using a serious chunk of piezo material. 20khz is getting high enough where at the very least a piezo transducer will be much more compact if not more efficient. If some resonance can be tolerated (probably not) it certainly will be more efficient.