In article ,
Martin Brown wrote:
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.

Piezo speakers can be made to do a range of sounds and tunes

Think you mean a limited range of tunes. They are simply a version of a
loudspeaker and have to conform to the same rules as those.

and are
plenty loud enough for a domestic dwelling.

Depends on the dwelling.

It isn't hifi but neither is
it just a manky fire alarm klaxon.

Your fire alarm sounds as often as your doorbell? There must be a gag in
there somewhere.


Flash mode too for totally deaf.

So you have to position the unit were it can be seen at all times? Very
convenient, that.

--
*See no evil, Hear no evil, Date no evil.

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