Comments on: Speaker as a microphone

By: sandeep chaudhary

sandeep chaudhary — Sat, 14 Nov 2009 09:46:35 +0000

To reader
im so glad to see various devices on the net i want take your help for donin something on my life.

By: Thomas Bailey

Thomas Bailey — Mon, 17 Aug 2009 05:12:51 +0000

I particularly liked the results I got whan I used an 18″ woofer for a microphone. I’ve heard of large-diaphragm microphones, but 18 in (457 mm) is huge.

By: cliff

cliff — Wed, 31 Oct 2007 18:24:09 +0000

after looking at the circuit, i wonder about impedance of this device since the transformer is a 1:1 and the coils are 4 ohm each. does it react favorably with preamps, and how would it compare with commercially manufactured mics?

By: Marco

Marco — Mon, 29 Oct 2007 23:48:22 +0000

“Hmmm, not so sure about using headphones as a PC mic, The PC provides a DC voltage to the right bud, I guess that others here might know if that DC voltage was enough to overheat the bud over time.”

Shouldn’t be a problem. Typically it’s only a 5V bias designed to drive the electret microphone pre-amp at ca. 1 mA. I would be surprised to find a commercial device that does not have some kind of current limiting in case of a short circuit.

By: Scrappylaptop

Scrappylaptop — Mon, 29 Oct 2007 21:31:03 +0000

Wow, I mean just wow. In other news, water can be used for drinking AND bathing!
Seriously, folks. Take apart an old microphone from the 50's; it's a speaker!
Remember in grade school how the PA system speaker was also a microphone?
This goes waaaay back to when they actually were the same thing; I even have an ancient bakelite telephone where instead of the mouthpiece having a carbon mike, it'...just another speaker!

So as to not just gripe and groan;

Other uses for speakers and/or microphones:
-Poor man's laser show:
lay raw speaker on back.
lay a mirror on it so that one end is supported by the speaker.
Aim laser pointer at mirror onto ceiling. play music.

-Poor man's actuator:
-strip most of the cone off or make holes so that air movement is reduced.
use to move parts of halloween display, such as eyelids or lips.
recorded speech makes a good signal source.

-passive (resonance) amplifier / frequency selective microphone:
-take Aluminum tubes about 1/4 inch in dia, cut to various lengths. Bundle together.
attach speaker to end of bundle (air tight, please).
Each tube if cut carefully will amplify a single frequency only, picked up by the speaker.

By: Stephen-C

Stephen-C — Mon, 29 Oct 2007 21:22:38 +0000

Just think, if someone had discovered this 45 years ago, Jack in the Box might have pioneered the drive-up window…

By: neoxide

neoxide — Mon, 29 Oct 2007 12:19:12 +0000

This is a classic ‘hack’.

Since I have virtually no cash, I use a car speaker (found in trash, of course) as my main mic. It sounds terrible, but alright for rough demos. From a 4 track tape recorder.

By: strider_mt2k

strider_mt2k — Mon, 29 Oct 2007 02:03:16 +0000

All hail transducers!

yay

By: samurai

samurai — Mon, 29 Oct 2007 00:32:30 +0000

this has been a common dj trick since the late 70s… if you dont have a mic at your mixer, just plug your headphones into the mic jack, make your announcement, and plug em back into the cue jack.

By: Will

Will — Sun, 28 Oct 2007 18:50:57 +0000

I saw this in... "Honey, We Shrunk Ourselves"
http://www.imdb.com/title/tt0119310/
I believe, in his midget status, he scrapes some of the solder off, which does some funky film magic and makes it a microphone...

By: eric

eric — Sun, 28 Oct 2007 18:39:07 +0000

will: you can solve the dc voltage problem by putting a capacitor in series with the headphones.

By: eric

eric — Sun, 28 Oct 2007 18:36:34 +0000

I was using speakers as microphones back in 1980. I accidentally discovered it playing with my brand new state of the art cassette recorder. I actually got better sound of the speaker than I ever did any mic that I could hook up to it AND it was significantly more sensitive. I used it to record my parents talking with my uncle 2 rooms away and I couldn’t physically hear them at all with my ears but I could hear them loud and clear through the recorder. Since then I’ve used speakers as microphones several times, even recently.

By: Wesley

Wesley — Sun, 28 Oct 2007 15:45:59 +0000

open headphones work reasonably well as a microphone

By: Bhima

Bhima — Sun, 28 Oct 2007 14:36:33 +0000

While this is very cool, I am beginning to find the instructables website rather annoying.

By: EthanV2

EthanV2 — Sun, 28 Oct 2007 13:48:02 +0000

Hmm, might have to try this with the Sub from my Logitech Z2300’s when i get my Z5500’s