Electronic Tuning

Anthony Willey's recent capture of different partials on note C5 in (A review of Steven Norsworthy's YouTube video: The Piano Sound is a Moving Target | Pianotech) got me curious about what I had seen when moving the mic for certain notes in TuneLab.  So I took another quick video of what happens if I select higher partials instead of the default one.  Long story short I noticed that:

• The reading becomes a lot more stable with the higher partial
• The readings don't quite exactly match each other at different partials.  There does seem to be about an 0.2c variation between them.
• I didn't show this in the video, but once I selected the 3rd or 4th partial it didn't matter where I put the mic
• I believe this matches the graphs Anthony posted for C5 in his situation, although in his case the problematic partial was the fundamental; in mine it's the second partial and I didn't actually try the fundamental.

I really want to emphasize that no matter which partial or mic placement I use, the phase display is consistent immediately after the attack.  And both the phase and numeric readout are consistent after about 2s in.

As before, I did this with a single string of C4, chosen because it happened to be one of the more problematic notes that I found when poking around.

For reference, the previous video is in the main "pianotech" library here.

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Nathan Monteleone RPT
Fort Worth TX
(817) 675-9494
nbmont@gmail.com
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"Mic" not "mnic".  :facepalm:

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Nathan Monteleone RPT
Fort Worth TX
(817) 675-9494
nbmont@gmail.com
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Nathan, you need to look at many notes across the range of the piano.

Look at the new Part 2 Video I posted. https://youtu.be/KIxAY4u__gQ

I examine the partials of notes C2, C3, C4, C5, C6, C7 from my Fazioli F308.

Generally one cannot and should not use an existing app, because we don't know what is going on in a given app. We have to use a raw signal processing algorithm outside the app, which is what I do here.

Steve N.

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Steven Norsworthy
PianoSens
Cardiff By The Sea CA
(619) 964-0101
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For what it's worth, I don't mean this to be part of any comprehensive research -- it's just a finding / usage tip for single-partial ETD's.

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Nathan Monteleone RPT
Fort Worth TX
(817) 675-9494
nbmont@gmail.com
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