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oops. sorry about this post.
seems i'm the dummy, and my post might qualify for doofus of the month

What are you comparing to the 12th harmonic...??

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A person who has never made a mistake has never made anything!!!

Before the common availability of electronic tuners, we used to intonate guitars by playing the harmonic and comparing it with the fretted 12th note

If your friend is telling you to set the intonation by checking the harmonic is in tune, he is mistaken.
It is a common false belief.

Phil : The open string and the 12th fret harmonic will always be the same note only an octave apart. Use a tuner and match the open note to the fretted 12th fret note. They should be an octave apart. If the 12th fret note is sharp the take off point on the saddle has to be moved back and the opposite if it is flat.
Tom

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A person who has never made a mistake has never made anything!!!

First of all, on an equal temper scale a guitar is only in tune at the fret you tune it to. When you press a string down to a different fret you strench the string differently. The further up the fingerboard you go the more the string is stretched (sharpened). So Fretted instruments are tuned open then ‘intonated’ at the mid point to bring them back into tune up the fretboard.

So you intonate to bring the guitar back into tune at the twelvth fret (half way). You use the harmonic because if the string is in tune open (say E on the 6th string) then the harmonic will be in tune although an octave higher. That is not true for an un-intonated string plucked at the 12th fret

When you intonate you compare the harmonic (right in tune) with the fretted 12 (not in tune until you make it that way by lengthening/shortening the string length.)

If the question is why not use the open string and the 12th fret to intonate, then my answer is I'd guess it is acceptable. I suppose it is better to use the harmonic because it is the same octave and you can actually hear the differences easily with your ear whereas it is much harder for me to discern differences when they are an octave apart.

Anyway, my 2cents, which by the way is close enough the way I intonate.

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Joe Beaver
Maker of Sawdust

The only problem with the 12th fret/1st harmonic comparison is explained very well in Trevor Gore's book, which points out that although that fixes the 12th fret note, all the compensation is applied between the 12th fret and the bridge saddle, which means that the frets below the 12th end up out one way, and those higher than the 12th are out the other way..it's a small effect but some people can hear it. Also the 1st harmonic of a string, although it should theoretically be exactly an octave higher, is slightly more than that due to the stiffness of the string. I'm quite keen to see for myself if following Trevor's advice can produce a guitar that tunes better, but the theory is pretty convincing. The idea is to compensate at the nut and the saddle... splitting the compensation between the two.

Alan

Hit open string,
hit harmonic at 12th,
hit fretted at 12th.
When they're all the same,
you're good.
Use a tuner,
or your ears.

This Mike Doolin article isn't for dummies unless you consider the fact that I read it three times now and I'm still trying figure it out.

http://www.doolinguitars.com/intonation ... tion1.html

There are a couple of problems when one is chasing perferct intonation.
1. There is no such thing as perfect intonation.
2. A good ear is both a blessing and a curse.
Tom

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A person who has never made a mistake has never made anything!!!

A compensated nut such as those made by Earvanna can make a real difference in intonation over the entire fretboard. I've put a couple on now and they make a real difference.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

Thanks Mr. Brian, I may try one of those. I play with power chords and distortion which really amplifies poor intonation. I am thinking of investiong in a good strobe tuner as well. I'm an amatuer builder and I really appreciate your tips.

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