In article ,
wrote:
On Tuesday, 13 December 2016 11:05:08 UTC, wrote:
Piezos are very power efficient but they just don't have the
required volume. Old mechanicals do.

Piezos and other electronic sounders have just about replaced
conventional bells in fire alarm systems due to low current requirement
enabling more sounders to be used, for uniform volume coverage.

Piezo sounders tend to be tuned to a particular highish frequency for best
efficiency. Perhaps ideal for an alarm, but not sure I'd like that nasty
noise as a door bell.

Other thing is of course they're much cheaper to make than a decent bell.

--
*Just remember...if the world didn't suck, we'd all fall off*

Dave Plowman London SW
To e-mail, change noise into sound.