show frequency

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julob
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show frequency

Post by julob » Sun Apr 03, 2011 8:31 am

Hello,

I am new to audacity and need a little help.

Basically I have melody and I want to not it down to the music sheet.
I have filtered frequency range and now I need show frequency to find out exact tone.

My idea is, that I select some part of the melody, for example one second, and basically I only need to count the peaks (waves) to find out frequency.

I know, this is totally primitive way how to do that, but I am not very skilled in this kinds of software.
If you know some more efficient solution, I will be glad for any advice.

Thank you for answers

Trebor
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Re: show frequency

Post by Trebor » Sun Apr 03, 2011 9:07 am

select part of the waveform then "Plot spectrum" [in the "Analyze" menu] ... http://manual.audacityteam.org/index.ph ... alyze_Menu

steve
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Re: show frequency

Post by steve » Sun Apr 03, 2011 9:41 am

You may do better with specialist software for this job. Try Googling "wav to midi freeware" or something similar.
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avalon
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Re: show frequency

Post by avalon » Sun Feb 12, 2012 1:04 pm

Let me revive this thread. I'd like to check if our piano (and other pianos) is tuned. I have tuner android application for the phone but it's not very easy to use for the purpose (although given enough time task is feasible).

I'd like to record a files with all keys of the piano pressed after one another and then check that the sound had the necessary frequency [1][2].

Any recommendations how to do so? Looking at a test file I'm not sure which settings would produce best result. I'm having varying results and the frequency that should go on top don't always appear strongest on the plot. Perhaps different settings for the different frequencies?

[1] http://en.wikipedia.org/wiki/Piano_key_frequencies
[2] http://www.phy.mtu.edu/~suits/notefreqs.html

steve
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Re: show frequency

Post by steve » Sun Feb 12, 2012 4:10 pm

avalon wrote: Looking at a test file I'm not sure which settings would produce best result. I'm having varying results and the frequency that should go on top don't always appear strongest on the plot.
Look for the highest peak that is close to the expected frequency.
Set the "Size" parameter in "Plot Spectrum" to a high value (8192 should work well) and expand the Plot Spectrum window to full screen.
Hover your mouse directly below the peak that is close to the expected frequency and look at the "Peak" read-out just below the graph.
If there are two or three peaks very close together, that is because piano notes usually have 2 or 3 separate strings. Ideally all the strings for a particular note should be exactly in tune.

In this (badly recorded) piano note, the "expected frequency" is 523.25 Hz ("C" above "middle C").
If you look closely you will see that there is a double peak (527 and 538 Hz) indicating that the piano is out of tune (sharp) and that the strings for "C" are not in tune with each other (a bad "honky-tonk" sound).
out-of-tune-piano.png
out-of-tune-piano.png (19.16 KiB) Viewed 12201 times
"Plot Spectrum" is not a very good way to tune an instrument as it is difficult to measure the frequency precisely enough. Hardware "chromatic" tuners are generally better.
9/10 questions are answered in the FREQUENTLY ASKED QUESTIONS (FAQ)

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