journeyman
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tuning question
If I tune the 3rd between the F and A strings perfectly, the higher strings are slightly flat in relation to the bottom C and F strings. So, I started
tuning that 3rd slightly sharp. It doesn't sound as nice as a perfectly in tune 3rd, but now the top strings are in tune. Does anyone have any
thoughts on this? -Roy
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Jody Stecher
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Interesting topic, Roy. Yes I do think about it and occasionally this anomaly causes tuning problems. My solution, as follows, usually works:
I begin with gg which I tune to a fixed pitch source ( an electronic tuner, a piano, a pitch pipe, etc.) I then tune the remaining 3 of the 4 upper
courses in perfect fourths by ear, as perfect as I can, which may not be perfect but is a lot better than what an electronic tuner would give me. I
then tune the FF course so that the first course cc is a perfect fifth above the octave of the FF course. Then I tune the low C course 2 octaves
below the high cc course. If I'm playing something where the AA course is the tonic, then I check the AA with a fixed pitch source and make any
necessary adjustments.
This works for most things I'd want to play. So far, nothing I play needs a sweet perfect third between the FF and AA courses. My fingered A notes on
the dd or gg courses are supported by the overtones from AA and dd courses, so it's ok that the 4th upper partial in the overtone series from the FF
is slightly flat to that and it's ok that the third between the FF and AA open courses is awfully wide.
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Brian Prunka
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Jody's process is similar to mine, which I'll outline below. The reason for this is that 4ths/5ths and 3rds are based on different tuning ratios, and
while this is not necessarily a problem if you stick to one or a few keys, it is problematic if you are using the wrong reference for your needs.
In Arabic music, the reference is the nawa string (written and nowadays mostly tuned to g below middle c', written an octave higher than it sounds).
Pure 5ths are tuned to a 3/2 ratio. 4ths are derived from switching octaves (2/1 ratio going up or 1/2 ratio going down). If we take G as being
196hz, then D below is 147hz (196*3/2)/2 and A is 110.25hz. To get C above G, we treat C as the reference so that 196Hz=XHz(3/2), where X represents
the frequency of C below G (130.666_Hz) and raise that up an octave, which gives us 261.333_Hz.
For reference, here are the pure tones vs. equal tempered equivalents:
C Pure5=261.33Hz ET=261.63Hz (ET is ±2¢ higher)
G reference= 196Hz
D Pure5=147Hz ET=146.83Hz (ET is ±2¢ lower)
A Pure5=110.25Hz ET=110Hz (ET is ±4¢ lower)
As you can see, these are fairly close.
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Brian Prunka
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For F, we get 87.1111_Hz following the same formula, compared to 87.31Hz for ET (about 4¢ higher).
2¢ is generally considered undetectable except in unusual circumstances, and 4¢ is the beginning of detectable tuning differences . . . so equal
temperament is actually OK for the open strings (putting aside the issues of unreliable tuners).
Now, what happens if we just get to the A, and tune the F so that the A is the third of the F?
Thirds are tuned in a ratio of 5/4.
A = F(5/4), so A/(5/4) = F
If A is 110.25, then F = 88.2Hz
This is about 22¢ higher than the one we got by tuning the F and C together, and about 18¢ higher than ET! No wonder you notice it . . .
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Brian Prunka
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So here is how I tune:
g to a reference
c' to g
d to g
A to d
So far, just like Jody. What I do different is that I touch the 3rd harmonic of the F string to get a C an octave and a half up, and tune that in
unison to the c' string (basically the same as tuning the F and C to a 12th but easier to hear and more reliable), then do the same thing with the low
C and the g (play the third harmonic and tune unison to the g string). The third harmonic is located where the neck meets the body.
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Jody Stecher
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I often do that as well. It is a reliable way of determining "a fifth above the octave of the fundamental".
Quote: Originally posted by Brian Prunka  |
So far, just like Jody. What I do different is that I touch the 3rd harmonic of the F string to get a C an octave and a half up, and tune that in
unison to the c' string |
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journeyman
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Wow, you guys are heavy. Thanks so much for this; I'll check it out for sure.
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Masel
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just want to add i tune the same way Jody and Brian mentioned.
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journeyman
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Just wanted to say thanks for the instructions on tuning Brian and Jody. That method works great and takes the guesswork out of tempering that 3rd
between the F and A. -Roy
roypatterson.com
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Brian Prunka
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You're welcome!
For reference, if you actually wanted to play in F (and have the A in tune), you would tune the F, C, and G to one another, then the A to the F and
the D to the A . . . this would leave the D and G out of tune with each other, which is less of a problem but still an issue. You could mitigate this
by tuning the A slightly sharp and the D and G slightly flatter to spread that 22¢ out between the different intervals.
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