RadioBanter - View Single Post - 32-ohm earphone speaker as a dynamic microphone

Lostgallifreyan · July 27th 14, 05:23 PM posted to rec.radio.amateur.homebrew

Stuart Longland wrote in news:he0fab-
:

These are speakers with dimensions not too dissimilar to small dynamic
elements with an impedance of 32ohms. Question is, how well would these
work as microphones? Has anyone tried this and can share any insights?

Try it. I think it wil work well enough for voice bandwidth. I remember from
playing with parts as a kid, that of all the coil-and-diaphragm transducers
in the world, the closest approach between mic and speaker was pretty much
where you've found it to be.

The impedance is not critical either, as you can drive a much higher imput
resistance, and low noise gain is all you need to make good use of the
signal.