stereo microphone for electromagnetic waves

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stereo microphone for electromagnetic waves
www.danielmace.ca
You can build a microphone capable of picking up
ambient electromagnetic waves (fields) without
picking up sound waves using the disposible
headphones offered on Air Canada flights. The
following images and text will guide you through
the surprisingly simple process of transforming
the headphones into a microphone. The entire
process should take no longer than 20 minutes and
could take much less. You now have a tool for
hearing the invisible waves through which we
navigate every day of our lives.
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You can use air canada headphones as well as many
other headphones or telephone ear pieces to get
the delicate speaker diaphragm and copper winding
(with a permanent magnet situated within this
copper coil) which will serve as a microphone for
picking up electromagnetic fields. It is
important to find headphones or earpieces with
the permanent magnet inserted into a plastic
housing, so the magnet can be removed without
destroying or overly disforming the other
components.
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Carefully remove the outer housing of the
headphones without breaking the various plastic
components which will allow you to put it all
back together to house your future microphone.
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The air canada headphones work nicely because the
permanent magnet is only glued into place in the
center of the plastic body housing the speaker
components. Adjust a pair of locking pliers to
grip the magnet firmly but without deforming it,
while avoiding the delicate wires which are
connected to the solder points on the back of
this piece. A careful twisting motion, back and
forth, will usually free the magnet which can be
removed, exposing the inner coil and diaphragm.
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One magnet removed and one to go!
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You can see the light glue line within the
plastic rim of the speaker with the magnet
removed, and the light but firm grip of the
pliers on the second magnet.
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Another look at the copper coil... So fragile yet
so effective for registering the presence of
electromagnetic waves.
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A close up look at the inner speaker housing and
copper coil.
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This is the plastic diaphragm side of the speaker
with the copper coil glued to the backside of the
diaphragm.
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Now replace the speaker module, with the magnet
removed, into the original headphone housing and
your stereo microphones are ready to go!
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The new stereo headphone microphone is now
plugged into the mic input on an Edirol digital
recorder... The first recordings were done with
a high gain setting and stereo input from
external microphones.
Listen to a recording done using these
electromagnetic stereo microphones... The various
electromagnetic sound sources include the edirol
recorder, a laptop computer, a powerbar and other
household sources of electromagnetic fields...
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Theremax theremin in hand sculpted case...
visit www.danielmace.ca/arts and www.kathykennedy
.ca for more art
Mace - stone sculpture
Kathy Kennedys sound art, hummm, chorale and so
much more...