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I bought my first kalimba a few days ago and it figured out it needs to be tuned.

I started tuning it using two different smartphone apps and noticed something strange: everything works fine — except for one tine that is supposed to be C5. It sounds correct and sometimes is recognized as C5, but most of the time both apps say it is F2.

The difference between these frequencies is huge and I don't understand why — I also haven't ever played any instrument before and know nothing about notes.

Can anyone explain why is it like that? Is my kalimba broken or maybe I hit this one tine incorrectly?

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    Many smartphone tuner apps work quite well, but you might get better results (and some added convenience) by buying a tuner that clips to an instrument and reads physical vibrations via a pickup, instead of a microphone. That's assuming that there is a handy place to clip it, and that you get a model that can read all pitches, not just the pitches of guitar strings. Nov 3, 2023 at 15:29

2 Answers 2

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C5 is the sixth harmonic of F2. I'm not sufficiently familiar with the sound spectrum of the kalimba to know whether there's anything that would make this particularly likely, but the software is probably identifying some lower-frequency element of the sound that isn't particularly audible and ascribing to it more significance than it should.

Is my kalimba broken or maybe I hit this one tine incorrectly?

No.

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    C5 is also beyond the range of a standard guitar and even most ukuleles, while F2 can be difficult to pick up on some smartphones' microphones. The app may be assuming OP is tuning a bass and trying to compensate by deducing the fundamental frequency from the overtones. Nov 3, 2023 at 15:15
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    @MaciejStachowski that sounds like a good answer.
    – phoog
    Nov 3, 2023 at 15:29
  • @leftroundabout Indeed. The fundamental vibration mode of a string or other system is harmonic motion!
    – Kaz
    Nov 3, 2023 at 23:30
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Many digital tuners use a simple autocorrelation algorithm to detect the pitch of a signal. Since F2 = 87.31Hz and C5 = 523.25Hz ≈ 6*87.31Hz, the presence of any extraneous tones with frequency n*87.31Hz, especially for n coprime with 6, could cause the autocorrelation algorithm to give a larger peak for 87.31Hz than for the intended 523.25Hz tone. This extraneous tone could be another tine on your kalimba being excited sympathetically.

Or, in less technical terms, the algorithm can't tell the difference between an F2 being played and two different notes being played that happen to be harmonics of F2.

There doesn't actually need to be an 87.31Hz component to the sound to fool the tuner.

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