Re: Secondary Harmonics
Walter Knapp <>
Wed, 04 Jun 2003 13:25:41 -0400
> In a message dated 6/3/03 4:16:45 PM Pacific Daylight Time,
>>Yes, real-time spectrogram applications may add spurious harmonics
>>because they need to use simpler algorithms in order to execute fast
>>enough on slower machines. However, a good off-line spectrogram
>>software should not introduce any false harmonics.
> Dear Experts,
> Does anyone know if CoolEdit Pro's spectrogram would add spurious harmonics?
I don't run cooledit, but have seen harmonics in sonograms others have
done which don't show up in some of my sonogram programs.
Note I get far more false harmonics out of my off-line sonogram program
than I do off the realtime sonograms from Spark XL. Regardless of which
calculation options I use. Each type of calculation has different stuff
it's likely to show that's not there. It's all part of becoming familiar
with the particular sonogram programs you use.
The easy way to find out is simply to do your filtering and see if they
are filtered out or not. Note that usually false harmonics are very
sound intensity dependent, typically only turning up on high intensity
As far as slower machines, modern machines are so much more capable than
those for which all these programs were written there is little reason
to dumb down the programs. They do often have to be rewritten from the
ground up to properly do realtime sonograms.
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