Tuning a guitar by comparing harmonics on adjacent strings

[poptart]

In another thread it has been insisted that you can correctly tune a guitar by comparing harmonics on adjacent strings.

It is my position that although guitar players that don't know any better frequently do this, it is not possible to correctly tune a guitar with this method.

When you play a harmonic on a string you are dividing the string into simple integer ratios. The harmonic at the 12th fret is twice the frequency of the open string, a realtionship of 2:1 (an octave). The harmonic at the 7th fret divides the string into three parts, the harmonic at the 5th fret divides the string into 4 parts. Dividing the octave up like this works great when you only play in one key, it is called just temperament. It will sound very out of tune if you attempt to play in a key other than the fundamental of the open string.

In order to play in more than one key modern instruments divide each octave into 12 equal steps so that all keys sound equally good, or more accurately, equally bad as every key has the same deviations from perfect just temperament. This is called equal temperament. The price paid for being able to play in more than one key is the loss of perfect integer ratios for some of the notes. The perfect fifth is the interval in question in this case. On an equal tempered instrument the perfect fifth is supposed to be 2 cents flat from the ideal 3:2 ratio. If you were to follow this harmonic tuning procedure starting at the low E string you would go 2 cents sharper than you're supposed to with each comparison meaning you're ten cents out by the time you get to the top string.

The exact same thing would happen on a piano if you were to misguidedly tune in perfect fifths right across the keyboard except the error is compounded to a much higher degree. The circle of fifths will not close using this perfect ratio, when you get back to the note you started on it will be way too sharp.

You can argue that you prefer an instrument that is not equal tempered, that's fine, but I don't see how you can argue that tuning an equal tempered instrument like a guitar using mathematically perfect fifths makes any sense. Any cheapo electronic tuner will show you your error if you do this.

[Pan]

Originally posted by poptart
[B]In another thread it has been insisted that you can correctly tune a guitar by comparing harmonics on adjacent strings.

Who claimed this,when and where?

Hint, nobody did, it's in your head.

Point this out or realise that your are mistaken. My guess is that you feel irritaded becasue you fail to understand some basic things about nonlinearity in audio devices which I had to repeat a couple of times to you.


/Peter

[poptart]

I'm not the least bit irritated. I find audio like a crossword puzzle, not a personal test or holy war. Participating in these forums gives me some puzzles to think about and pass the time in an otherwise boring day.

Your posts on the other hand seem highly emotional as if you feel I'm causing you physical pain or something. It's just a discussion.

Who claimed this,when and where?

I thought you were dismissing my point with your claim that guitar tuning is a huge and mysterious subject. Why on earth did you reply to this tiny point so many times if you agree that guitars can not be tuned by the harmonic method. You could have ignored it or just said "yes, that's true".

[Pan]

Originally posted by poptart
Your posts on the other hand seem highly emotional as if you feel I'm causing you physical pain or something. It's just a discussion.

I prefer not wasting time on this type of discussions, and I do become irritaded when these kinds of discussions pop up simply becasue someone can not read properly. It's a total waste of time but at the same time I do not like to have stuff unsorted either. That's me! :-)

I thought you were dismissing my point

Yes I know you thought that, but if you read carefully and think about it I hope it will become clear to you that I never did.


I hope the situation becomes clear to you know.


Cheers!


/Peter

[Minion]

Do you mean like tuneing the Low E string at the 5th fret Harmonic with the 7 th fret of the A string Harmonic.....

If so i have never had a problem when tuneing this way, it is just as accurate for me than useing s Digital tuner and compareing the Two (harmonic tuneing and useing a tuner) It seems just as in tune either way.....

confused??

[poptart]

Pan,
I'm sorry you got so worked up about what amounts to nothing then. I hope you do stick around these forums but I hope also you are able to leave your emotions out and simply discuss the technical details more. I notice I am not the only one you seem to be getting emotional with. I was not the one that brought your experience or knowledge into the conversation, that was you. I wasn't even the one that brought up the guitar. I merely posted a short comment about it after it was already introduced.


Minion,
That is the technique in question yes. If you tune your low E to some external reference then tune your A string to it by comparing the harmonics you have not made a large error, 2 cents will hardly be noticed. The problem becomes audible if you continue across the strings this way. Assuming you could hear the harmonics clearly and absolutely eliminated the beating between them, your A string is now 2 cents sharp of where it should be. If you repeat the process by comparing the A string and D string harmonics and eliminating all beats you now have a D string that is 4 cents sharp, and on it goes until you reach the high E string and it's 10 cents sharp compared to the low E string, this should easily be heard and seen with even a cheap tuner. For what it's worth you're not likely to do better using unisons and tuning from string to string this way as any error you make will again be compounded as you move to the next string. The only reliable way is to compare all strings to one string so the errors you make don't add up. (or of course use a tuner)

[Pan]

Originally posted by poptart
[B]Pan,
I'm sorry you got so worked up about what amounts to nothing then.

Well, I was not that worked up but you were wasting my time by not reading carefully. I MUCH rather talk about audio than spending time sorting out misunderstanding based on someone who is not reading carefully, particularly when it's a off topic thing that I clearly express a wish not to have in the thread but the "opponent" jus go on! ;-)

I hope you do stick around these forums

I've been here since 2002 and will likely stay.

but I hope also you are able to leave your emotions out and simply discuss the technical details more. I notice I am not the only one you seem to be getting emotional with.

It would be a nice things to not judge a person on a single happening. Yesterday was a strange day becasue two persons was reading in things I did not say in two different threads. I don't end up in these situations very often, actually very seldom.

I was not the one that brought your experience or knowledge into the conversation, that was you.

Yes, since you were putting words in my mouth I wanted to give such information that you could realise that I actually had some understanding about guitar tuning. On one side you still assume tht I do not understand guitar tuning even though I have thies long experience, on teh other hand you state that it's a simple thing that any one could get the hang of in 5 minutes with a uitar and a tuner. Now, if that is not questioning my intelligence I don't know what. And no, I was nort intimidiated or hurt by it, i merely wanted to point out to you that you did not make much sense.

I wasn't even the one that brought up the guitar. I merely posted a short comment about it after it was already introduced.

Which really does not matter.

Now, go tune your guitar and have a nice weekend! :-)


/Peter

[poptart]

Maybe it's a cultural or language thing but all your responses including this most recent read as arrogant and undiplomatic to me. I guess we just don't make sense to each other. I'll try to steer clear of you for both our sakes.

[wxn]

optart is correct. I have noticed this on bass guitar. It's fretless so I can very accurately tell if it's tuned incorrectly. The difference is small though. Even the worst case is still playable, especially on a non-chord instrument.

[voldigicam]

Of course it's possible and routinely done. The underlying assumption in the OP is that one is tuning the harmonics to a unison. The correct way is to tune to beats, as in tuning a piano, taking into account the specific guitar. When I used to actually play more than working on the things I'd use harmonics to set the guitar close - really very close - counting beats. Although counting isn't necessary; one gets a very quick idea of how fast the beats are and learns when they're close enough. Then tuning through a series of open chords to test the tune and make adjustments. Some folks shift the tuning very slightly for different keys. Certainly for some pieces certain notes or sequences figure prominently; I'd tune for those to be perfect and just fudge the remainder.

Those frets are a bit problem, pinning the pitch fairly strongly. Fretless instruments don't have that problem and really let intonation manipulations come into play nicely.