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Re: Re: Son of Cheap stereo, uh, bit less cheap.

Subject: Re: Re: Son of Cheap stereo, uh, bit less cheap.
From: Marty Michener <>
Date: Sat, 05 Apr 2003 16:38:56 -0500
At 12:45 PM 4/5/2003 -0800, you wrote:
>Marty
>   I liked your inclusion of a superposition graph so
>much that I included it on my page.
>http://www.akwebb.com/gkweather/ambient/selfnoise.html
>
>Do you think these graphs have much use in comparing
>different microphones?
>
>As an old retired high school physics teacher, the
>discussion of transverse and longitudinal waves makes
>me want to break out the wave tanks and slinkys and do
>some demos.
>
>I'll resist the urge.
>
>                           Greg Kunkel

Greg:

Yours looks even better in that format.  I was having transparency problems=

with my graphic program.  But it does show that your ambient is always
higher than your self-noise, making the mic useful for recording whenever
you get close to a specific desired sound source.  Yes, I think a field mic=

should definitely have some head-room to be effective, and it should show
well in such graphs.

When I taught Physics in HS, I made a pendulum set to demo wave
resonance.  I had about 20 pendulums - washers on strings - all hanging
from the tile ceiling in a line about a foot apart.  Each was slightly
longer than the previous neighbor.  Along the top of each string, about 2 "=

from the fulcrum (push-pin), ran a transverse string parallel to the
ceiling, and attached lightly with tape to each pendulum it passed.  At the=

end this traverse was tied in a loop around the big, adjustable, master
pendulum - big weight on heavy string.  Hanging from a pulley at the top,
this one could be adjusted to any chosen length by pulling it in or letting=

it out.  When you started the master big guy swinging, the motion was
gradually transferred to all the other (receptor) pendula, but only the one=

of the same length really picked up any energy, like a radio tuned to the
same frequency.  Passersby seemed amazed.

my best regards,

Marty Michener
MIST Software Associates PO Box 269, Hollis, NH 03049

EnjoyBirds.com  - Software that migrates with you.    http://www.EnjoyBirds=
.com



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