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Full screen of waveform

Posted: Mon Nov 04, 2013 1:47 am
by jpschmidt
Violin makers use Audacity to track the frequency of the plates as they shape the wood, and also of the finished violin. One thing they would like is a full screen shot of the waveform so that they can calculate the "Q" value, which is the inverse of the damping factor of the wood. The user would record a tap sound from the violin. This would be maybe less than 0.5 seconds of sound. After selecting the desired portion of the waveform, they would like to see it full screen so they can measure the height of each successive peak. This allows calculation of Q. As I said, many violin makers would use this. Well, maybe 200 or 300. But currently SpectraPlus is out of our price range.

Thanks

John

Re: Full screen of waveform

Posted: Mon Nov 04, 2013 3:06 am
by Gale Andrews
You can measure the peak value in a selection using Effect > Amplify (take the negative of the "Amplification (dB)" value shown).

You can export a text file of sample values using Sample Data Export .

For the screenshot, use Tracks > Fit Vertically then Help > Screenshot Tools . You can just click "First Track" in Screenshot Tools to export your screenshot.


Gale

Re: Full screen of waveform

Posted: Mon Nov 04, 2013 7:40 am
by jpschmidt
Gale,

Wow. That was quick. I will try it.

Thanks

John

Re: Full screen of waveform

Posted: Wed Nov 06, 2013 10:36 am
by Trebor
jpschmidt wrote:... But currently SpectraPlus is out of our price range.
A [free] real-time spectrogram may be of use ... http://forum.audacityteam.org/viewtopic ... 85#p182785