On Tuesday, 24 September 2019 06:00:48 UTC+1, Jeff Urban wrote:
** Mere supposition, not one tiny bit fact.

No, here's a fact, THEY ARE CAPACITIVE.

I have already had problems due to tape bias on those. Wasn't filtered out well enough. Couldn't hear the bias but you could definitely hear the hum..

Fact is any HF leakage out that class D amp will see a near dead short on the load if it is piezo. The idea was efficiency. Don't got it like that.

Sorry to intrude on your vision of perfection.

Piezo drivers are capacitive (albeit with a lot of resonance peaks/troughs), but piezo tweeters generlly include a transformer to raise the voltage, and are usually in series with an external resistance, since some amps don't like C loads. I've never measured one at half a megahertz, but expect it to look largely like a transformer at that f.


NT