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swilliams
New Member
USA
71 Posts |
 Posted - 12/12/2005 : 20:12:51
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A wee bit of knowledge can be a dangerous thing. In my youth I used to use the 12th fret harmonic to tune to , and set intonation. My rational was that the 1st overtone should be the same pitch as the open string, just an octave higher . I also thought harmonic seemed more ‘stable’ than the open string.
One thing that has become apparent since using Peterson hardware and software is that there is often a discrepancy between the open string and it’s 12th fret harmonic. I’ve noticed this in particular with ‘D’ strings (acoustic..phospher bronze).
Am I crazy? I guess this involves the physics of a vibrating string and how it is attacked. I’ve also noticed that ,especially on the low e, that the pitch changes dramatically if I pluck over the neck versus near the bridge. Comments?
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gomuncy
New Member
USA
58 Posts |
Posted - 12/12/2005 : 22:47:59
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Hi swilliams,
You have opened the door to my field of knowledge, "PHYSICS" as applied to the guitar. The opposite of knowledge is ignorance, and in time I hope to educate the guitar world about fret placement and the requirement for correct placement of all frets for tuning.
First: The rational of the 1st overtone to be the same pitch as the open string, and an octave higher is fact, look at the note frequency charts so graciously provided by Peterson.
Second: The physics of a plucked string is sympathetic to the point of contact on that string, example! plucking the middle of the string will set the string in motion EQUALLY to either side of the center point producing equal harmonics. Plucking the string at a point other than the center will set up unequal motion and unequal harmonics on the string.
Third: Errors of manufactured fretted guitars are responsible for a untuneable condition. A simple fret placement parallel to each other based on the Rule of Eighteen can not be tuned to exact frequencys.
Fourth: A fret must have a finite placement under each string, and it must change from a transverse plane across the fret at each additional string, fret contact point, or NODE.
Using Peterson hardware and software is the best tools to find a discrepancy between the open string and it’s 12th fret harmonic and all other errors on any fretted instrument, any scale, any number of strings, ect., ect,. Are you crazy ?, no way! you now have knowledge thanks to peterson.
Please check the posting about intonation on this forum, it will help you tune your instruments, but keep in mind you must change to a guitar with a system of finite fret node positions to be perfectly in tune. |
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swilliams
New Member
USA
71 Posts |
Posted - 12/13/2005 : 12:43:56
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"Please check the posting about intonation on this forum"
Thanks for the info. Which post are you refering to? When I do a search on the forums, several pages of related matter pops up.
Alex |
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gomuncy
New Member
USA
58 Posts |
Posted - 12/13/2005 : 22:34:16
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This is one of my postings
gomuncy
Starting Member
USA
23 Posts
Posted - 08/24/2005 : 22:57:14
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Hi David ,
I hope I can help you, tuning is a very complex procedure, and yet is so simple. I would recommend you take some time to watch the cause and effect, of your tuning. The Peterson tuner you have is your guide to excellant intonation. A simlpe study of cause and effect is easy and anyone can do it, so lets get started. " Always use equal temper tuning to intonate."
1. Pen and paper.
2. Test one string at a time, let us start with high E .
3. Pluck the string in the middle of the nut to the bridge distance, with the tip of your finger, always use this method.
4. Adjust the machines "tuners on the head" bring the note to pitch.
5. Fret the string at the " 12 fret " ,It is important to now pluck the fretted string in the middle, of the remaining length , write down the results.
6. A sharp or a flat note " E " will be displayed on your Peterson tuner.
7. Adjust the bridge to bring the note to pitch, shorten the distance of the string , and you will notice a sharpening of the note, lengthen the distance, and you will notice a flatting of the note.
8. You must now pluck the string in open condition,and tune to open pitch .
9. Fret the string at the 12 fret, and pluck as above, and write down the results, correct as above example.
10. The need to write down your results will set you up for testing in a scientific discipline, a system of rules. Repeat on the other strings.
Follow the instructions above and you will be tuning as accurate as anyone can, on a raised fret guitar. The results, and facts we recorded in a complete study of the guitar fingerboard, and fret string node finite position study, yielded this information as for tuning down 1 whole step. The note was still in pitch in open tuning and in tune at the "12 th" fret. Our guitars are not a riased fret design, and as such are not subject to the tuning deficiencies of raised fret guitars.
A raised fret guitar will always have variability of sharpness from finger pressure, at any fretted note, a fact of physics. Once the intonating in equal temperament tuning is set , you can change easily
to alternate tunings, such as GTR temperament, or "D", ECT.,.
I hope this helps you to always be in tune.
Professor Gary
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swilliams
New Member
USA
71 Posts |
Posted - 12/14/2005 : 10:56:09
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Thank you for the info. I'm inspired to be more meticulous!
Can you please clarify "Adjust the machines "tuners on the head" bring the note to pitch"?
Alex |
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gomuncy
New Member
USA
58 Posts |
Posted - 12/14/2005 : 21:49:33
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Hi Alex,
The " machines " are the tuners as most people call them, on the head stock. With your Peterson tuner on adjust the tension up or down until the note on screen is stationary. |
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Harmonics
