> However when run on the Hammond recording, it's detecting a wavelength of
> perhaps 0.7 cent off.
Interesting…I looked at this quickly, not an authority, but power line
frequency regulation (Hammond relying on synchronous motors for pitch, of
course)—in North America for 60 Hz—is adjusted
Evan thanks for the pointers to techniques. I haven't heard of them but
will investigate.
Ben thanks for the links. I actually have reviewed both but they'd have
been critical had I not. Did you note the Utility Frequency page had a
very surprising coincidental mention of Hammond?
Your "detecting a wavelength of perhaps 0.7 cent off" caught my eye,
as the Hammond tone generation is mechanically tied to the 50Hz or
60Hz power frequency, and I don't think the line frequency has ever
been regulated as accurately as 1 cent (1/100th semitone). For
accurate recordings, you'd need
Hello, Frank —
I tentatively ask what the "value under the curve would be" up to this
> zero-crossing. If the value is close enough to zero, then I treat the
> difference between this interpolated crossing and the first as a candidate
> wavelength.
>
If you're doing this, you certainly want to
Summary
I'm having trouble identifying exact frequencies in what should be an
extremely easy-to-process WAV file, as a first step to doing a harmonic
analysis with a Fourier transform.
Details of Project
I have a file which contains a second's worth of sound of each of the 91
tonewheels of
