[PD] Real-time frequency filtering and analysis

Charles Henry czhenry at gmail.com
Wed Mar 28 16:16:23 CEST 2007

filtering in general may not be the best approach because some of your
partials from one xylophone note will overlap with other note's
partials.  They are inharmonic complex tones, which are not so easy to
predict.... you'll probably have to measure the frequencies of each
note of your xylophone to know exactly what the spectrum is like.

In terms of averaging like Jamie suggested... suppose you want to
compute the expectation of the power spectral density.  You would take
the fft of the auto-covariance of your recieved signal, divided by the
number of blocks in your time frame.  (dividing by a number of blocks
will not in general be necessary, when all you need to do is find a
peak, with pique~ as before)
This will give you a very clear/accurate peak, without much
jitter/noise to clean up.


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