Replies to This Discussion

Permalink Reply by PKB on October 22, 2013 at 5:27am

In theory any old speaker can be used as an element correct?

Permalink Reply by Old Fingers Green on October 25, 2013 at 6:22pm

It can, I've done it a couple of times. Used the speakers from an old set of big headphones. It worked but it isn't very good, I also had some luck using a piezo disc suspended in a diaphragm of cling film. Worked surprisingly well.

I was given an ebook the other day of electrical circuits and there was a circuit diagram to make any miniature speaker into a microphone element. I'll have a look and post up when I find it. 

Permalink Reply by PKB on October 25, 2013 at 11:05pm

Just messing around the other day I took a 3 inch speaker and hooked it up to an old instrument cable I had lying around.

I plugged that into one of my homemade amps... It worked... Just not very loud. I really had to almost yell to hear anything at all and that was louder than my typical busking set up and thus, pointless.

I have a few Shure SM57's laying around and I looked at the elements in those and the diaphragm is a clear plastic, not the black paper material used in most speakers. I think the clear plastic requires less force into the microphone to drive. At work I found an old government rotary dial phone and checked the microphone in there and it is also a clear plastic driver.