[ntp:questions] measuring frequency

robert bristow-johnson rbj at audioimagination.com
Tue Feb 12 01:01:00 UTC 2013

On 2/11/13 6:48 PM, unruh wrote:
> ...
> Yes. However what you can do is to filter out the all but the strongest
> harmonic, and count which harmonic number it is.

how do you know what the harmonic number is?  how would that information 
be determined in the general case.

> Then you know how many
> zero crossings it has in an period of the fundamental and can count
> them.
> Of course with the piano, since they are not harmonically related this
> will give a small error. However the lowest ones are not too far out,
> (and besides the ear the actually uses all of the harmonics to decide on
> the pitch it will present to you).

well, the frequencies of the higher harmonics are a little sharp.  i 
think that affects the perceived timbre of the sound but not so much the 


r b-j                  rbj at audioimagination.com

"Imagination is more important than knowledge."

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