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Completely
understanding fundamental & harmonic frequencies allows
you to know where to place microphones and allows you to
really understand the use of equalization. |
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This 4
minute video clip has been shown to hundreds of
recording classes since it was produced in 1985.
It has always seemed to really help students get a good
understanding of this essential basic subject. |
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The screen
captures shown below tell the story. You can also
use the link below to download a higher-quality copy of
the audio track.
- Bob |
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Screen
Capture #1 shows a sine wave of 110 Hz - The
fundamental frequency of the A string on a guitar. |
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Screen Capture #2 shows the
waveform of an electric guitar playing an open A (The
A string without any fretting). |
Screen Capture #3 shows that the
electric guitar wave still generally follows the sine
wave shape, but with added bumps caused by the
harmonics. |
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Screen
Capture #4 shows the waveform of an acoustic guitar
playing an open A. It looks quite different than
the electric guitar waveform. |
Screen
Capture #5 shows that the acoustic guitar wave also
follows the sine wave shape, but the bumps caused by
the harmonics are smaller. |
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Screen
Capture #6 shows the waveform of an acoustic piano
playing the same A. It looks quite different
than either of the guitar waveforms. |
Screen
Capture #7 shows that the acoustic piano wave follows
the sine wave shape too, but has more bumps because of
more harmonics.. |
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Screen
Captures #8 and #9 show that the waveform of an
acoustic guitar miced over the bridge has the deepest
bumps, indicating the loudest harmonic content. Theory
tells us that placing the mic over the bridge accents
harmonics. |
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Screen
Captures #10 and #11 show that the waveform of an
acoustic guitar miced over the hole has the smallest
bumps, indicating the softest harmonic content. Theory
tells us that placing the mic over the hole accents
fundamentals. |
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Please
note that videos playing at a bit rate of 56 K bits/sec do
not have the best audio quality. For this reason we
also made a CD-quality downloadable MP3 audio file where you can
hear the differences in mic placement better.
Here
is the link to download it. |
