No disrespect taken.
Quote:
Originally Posted by Son of Magni  the reason we need compensation is to compensate for the fact that as the vibrating length shortens its stiffness has an increasing effect on it's pitch. So for any given string under a fixed tension, as you shorten it's length it becomes increasingly sharp compared to what you would calculate based on mass vs tension. |
I have been through that discussion before and have done a little testing to see what is what. Longer compensation is needed with higher action. That I don't doubt. Experience has shown me this. This is because the string is stretched to a greater degree. Try it and you will see. That doesn't completely discount the notion of a shorter string being stiffer but that is exactly what you want it to be to make the note change. If strings responded consistently like that we could simply change the fret spacing, get perfect intonation all the time and quit fiddling around with compensation.
Try this if you need to prove it to yourself. Make a fret shim that sits on top of your existing fret and fills the space that is normally your action at the 12th fret. Using a strobe tuner, set your compensation so that an open string and one fretted with the shim and a capo that does not stretch the string are exactly an octave apart. Measure the total scale length and you will be exactly double the distance from the nut to the 12th. Now remove the shim and fret normally or even aggressively and very close to the fret. The same string under the same tension at the same fret will intonate sharp.
Let me know if you get a different result than I did. Science requires multiple tests under similar conditions to come to any reasonable conclusion. When I did it it just proved it to me and no one else. If you get different results I may have to revisit my previous experiment. BTW. I was testing on a steel string acoustic which is shorter scale. I would expect the difference to be more easily measured with longer scales.
Greg N
"Can it add as much as 1/4 to 1/2 an inch?"
I guess you were posting when I was. Yes. Depending on string size, scale length and action that would not be unimaginable with the larger diameter strings.
A beginners guide to compensation. Get a good accurate tuner. Hit the harmonic at the 12 then fret the 12. The harmonic is the essence of an octave on the string so use that as your basis for adjustment, not the fretted note. If the fretted note is sharper than the harmonic then increase the distance from the saddle to the nut. If it is flatter, then decrease the distance. That will be good for 95% of the players out there. There are those who like different compensations due to the chords they typically play and their ability to hear things I honestly can't. They are few and far between so I wouldn't worry about them.
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