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Old 09-23-2017, 03:23 AM   #1
Mr. PC
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Default Manually tuning to harmonic series using pitchbend data.

So I want to start tuning midi notes individually, according to the harmonic series / simplest ratio principle.

These are the Equal Temperament frequencies of each pitch
https://pages.mtu.edu/~suits/notefreqs.html

So if I want to tune a pure 5th above A 110, (which would be A 165) I should tune the note up 19 cents, right?

And to add a C# (275Hz in the harmonic series) I should tune the ET note (277.18Hz) down... oh, I just realized this is wrong. How do you convert the Hz into Cents? I need something relatively simple, because I plan to tune almost every single note this way.

I found this,

https://i.stack.imgur.com/eMCQP.png

But it can't be the same Cents difference in every octave, right? Or is it?
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Old 09-23-2017, 05:25 AM   #2
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Quote:
Originally Posted by Mr. PC View Post
But it can't be the same Cents difference in every octave, right? Or is it?
Yes, because they all have 1200 cents for the octave.

Of course, that's only in theory, as real instruments will have wonky intonation over octaves, either by design (piano octave stretching) or as a byproduct of design (guitar).
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Old 09-27-2017, 08:31 AM   #3
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Originally Posted by Judders View Post
Yes, because they all have 1200 cents for the octave.

Of course, that's only in theory, as real instruments will have wonky intonation over octaves, either by design (piano octave stretching) or as a byproduct of design (guitar).
So if I'm using samples which are tuned in ET, then all I have to do is add 13.69 cents to any major third and get a perfectly tuned 3rd?

Minus 1.96 cents from any 5th and get a pure 5th?

It seems way too easy.
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Old 09-27-2017, 09:00 AM   #4
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So if I'm using samples which are tuned in ET, then all I have to do is add 13.69 cents to any major third and get a perfectly tuned 3rd?

Minus 1.96 cents from any 5th and get a pure 5th?

It seems way too easy.
If it's a piano then it won't be that easy, because of the stretch tuning.

Have you got a tuner plugin that gives exact hertz?

For anything that is tuned to actual equal temperament then yes, it is that easy. Probably seems like it shouldn't be because of how difficult it is to do with a real instrument.
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Old 09-27-2017, 02:09 PM   #5
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I suppose you're exploring the pitchbend approach because you must use an instrument that cannot apply other tunings, such as originating from scala in the format of .tun or kontakt script?
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Old 09-27-2017, 03:27 PM   #6
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Have you checked these pitchbend based tuners?
https://forum.cockos.com/showthread.php?t=21345

https://forum.cockos.com/showthread.php?t=176393
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Old 09-29-2017, 10:56 PM   #7
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I don't know if this will help you or not, but here is the relationship between cents and the ratio of frequencis in Hz

One semitone (or half step) is 100 cents.
There are 1200 cents in an octave.
The frequency ratio between 2 pitches of frequency1 and frequency2, if you know the number of cents between them is:

Freq1/freq2 = 2^(cents/1200), where "^" means 'raised to the power'

If freq1 > freq2 the cents value will be positive (so you can say freq1 is this many cents above freq2).
If freq1 < freq2 you would have a negative cents value.

To solve for the cents value for two frequencies F1 and F2 looks like this:
Cents = 1200 (log (F1/F2) / log(2) )

Last edited by Philbo King; 09-29-2017 at 11:03 PM.
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Old 03-11-2018, 09:32 AM   #8
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Hi everyone,

I'm coming back to this concept, and have found a cool online tool

http://www.sengpielaudio.com/calculator-centsratio.htm

Testing it with some different notes, it seems the cent-(de)-tuning is *not* consistent, but close. (Or maybe I'm doing something wrong, if someone can check my work, that'd be great.

For example

A3 = 110 Hz
E3 = 164.814 Hz

If I tune that E3 up to 165Hz (for a pure 5th), that calculator tells me I'll need to uptune 1.9526737328568047 cents.

Now

A4 = 440 Hz
E4 = 659.225 Hz

If I tune that E3 up to 330Hz (for a pure 5th), that calculator tells me I'll need to uptune 2.0340829538175997 cents.

{Edit... it seems my numbers for equal temperament are wrong. Actually, the equal tempered E5 should be 164.81400 x 4 = 659.25600, right? And in this case, the cent detuning remains 1.9526737328568047 cents. So stretch every E.T. 5th that amount and get a pure 5th, right?}
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Old 03-11-2018, 09:38 AM   #9
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Quote:
Originally Posted by ericzang View Post
I'm not sure what I want can be accomplished with these tuners (maybe the second one, I'm looking into it more tonight).

I'm trying to make every 'vertical' harmony line up with the harmonic series of the root note, so that every harmony will line up perfectly with the lowest instrument's overtones.
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Old 03-11-2018, 11:32 AM   #10
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Well... I`m not familiar with JSFX, but theoretically I can build static tuner. By "static" I mean tune whole MIDI item by spreading overlapping notes to 16 channels and apply pitchshift to each note based on user tuning (whatever pitch+cents or frequency) + pitchshift preference(depending on end synth pitchbend range). I can also take Scala files as tuning stuff. But this of course can take pretty much time.
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Old 03-12-2018, 11:51 PM   #11
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When I got an old upright piano about 12 years ago I bought a CD for tuning it that included about 100 different tuning temperaments. It's the most accurate tuner I've ever found, except for maybe the old Conn Strobetuner. It is now shareware. You might find it useful for what you are doing.

A few tips about using it:
- it will only work using a Win sound card (it is pre-ASIO and pre-USB)
- cheap crappy mics actually work better
- make sure to disable stretch tuning if you are not using it an an acoustic piano



https://www.tunelab-world.com/tl97.html
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