[Sean Conolly]

"Roy W. Rising" wrote in message
...

When Marketing asked Lou Burroughs to develop some condenser mics, he
said he would, but not until he could make them at least as good as their
best dynamics. He told me that during the development, photomicrography
was used to look at the condenser diaphragms while being bombarded by
sound. He thought the images might show something like annular rings,
resembling the wave of a "pebble tossed into a pond". Instead, he said
the
diaphragm more closely resembled what would happen if someone crumpled a
piece of aluminum foil and then tried to re-flatten it. Fascinating!

Now as a drummer, that makes complete sense to me. When you hit a membrane
(ok, different kimd of impulse but stay with me) you get all kinds of
complex wave patterns on the membrane. Below a certain level of tension the
membrane 'flaps' and produces a sound like, well in the case of a drum head
a piece of plastic flapping. When it gets above that threshold it resonates
and produces a composite tone. For a condenser diaphragm I suspect that the
optimal tension is just high enough to keep it from flapping, but resonant
below any reasonable frequency we can hear.

Not that I know crap about this stuff, I just see a parallel there.

Sean