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Guitar tuner that uses phone accelerometer

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Re: Guitar tuner that uses phone accelerometer

#101
post #86

Earlier quoted context omitted.

Every non-linear mixing of signals gives you sum and difference frequencies. It's less a weird PLL thing and more a weird trig function thing.

Its not even a non linear thing. Its a sampling thing. Even ideal sampling exhibits aliasing. https://en.wikipedia.org/wiki/Nyquist%E2%80%93Shannon_sampli...

Yes, and. You can look at aliasing as a special case of heterodyning. Sampling is a nonlinear mixing.

Re: Guitar tuner that uses phone accelerometer

#102

Earlier quoted context omitted.

Yes, but the computer doesn't have the firmware to "record" that signal from the speaker output pins. Thus, to record from the speakers acting like microphones, would require rewiring the headphone cable, for the vast majority of computing devices. If you click "record" on your computer, there's no way to tell it to record signal from the speaker output channels, even if you write a custom low-level application direc…

"Yes, but the computer doesn't have the firmware to "record" that signal from the speaker output pins." No, you plug directly into the microphone jack, that is what is providing your line level reference signal that gets changed by motion in the diaphragm. Zero rewiring required.

None of my 8 computing devices have that port.

Re: Guitar tuner that uses phone accelerometer

#103

Earlier quoted context omitted.

That sounds like a very useful skill for a working player. But it seems to come with a couple of significant conditions. I can believe this is possible. But I don't think this is a reasonable thing as a baseline expectation for a player with 6 weeks of experience, which was the original comment in this thread. I don't know the details, but I imagine you're feeling beats transmitted through the neck or something. But…

depends on the instrument. with acoustic instruments the resonance chamber is often tuned so that you can feel the body itself vibrating more when you're in tune

I don't doubt that this is true at some level. But is it really perceptible for 20cent differences? I don't know anything about this, but I'd be surprised. I'd say +/- 20 cents is a bare minimum for calling something "tuned", but low single digits is really the goal.

Re: Guitar tuner that uses phone accelerometer

#104

Earlier quoted context omitted.

depends on the instrument. with acoustic instruments the resonance chamber is often tuned so that you can feel the body itself vibrating more when you're in tune

I don't doubt that this is true at some level. But is it really perceptible for 20cent differences? I don't know anything about this, but I'd be surprised. I'd say +/- 20 cents is a bare minimum for calling something "tuned", but low single digits is really the goal.

no, i still use an electronic tuner with my acoustic guitar. but i can feel the body vibrating differently when i get close to being in tune vs being a semitone off

Re: Guitar tuner that uses phone accelerometer

#105

Earlier quoted context omitted.

I don't doubt that this is true at some level. But is it really perceptible for 20cent differences? I don't know anything about this, but I'd be surprised. I'd say +/- 20 cents is a bare minimum for calling something "tuned", but low single digits is really the goal.

no, i still use an electronic tuner with my acoustic guitar. but i can feel the body vibrating differently when i get close to being in tune vs being a semitone off

Semitone precision is not good enough to replace a tuner. I believed that's what we were talking about. Still cool and interesting though.
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