It isn't the most healthy waveform I've ever seen! lol. It's a little short of a space invader though
I don't know exactly what cross over distortion is. I will have to play with circuit and see what effect it has.
The piezo needs an inductance shunted with it for good power transfer I think. That is the principle of the humidifier circuit I have, it has never been clear to me whether I'd also have to shunt inductance when used with an amp...? So I don't think a half bridge would work.
I'm replicating a system in my previous job. They used a signal generator into an amplifier into a piezo. So this is the right path to follow. I wish I knew which amp they had used and had their schematic.
Cheers,
Antknee.