6th string, G# - Open/Harmonic different tuning readings

[Paul E. Brennan]

When I use my tuning meter (Boss Tu-12) on my Emmons LeGrande, I notice that the 6th G# shows a different reading when played open as against when played with a harmonic at the 12th fret. The open string reads higher than the 12th fret harmonic. This happens to a lesser extent on the other plain strings. Does anyone have an explanation for this phenomenon?

[Bill Patton]

You might try rolling off all the high frequencies before the sound hits the tuner (like running it through a pedal with eq). If that helps, it might be stray high frequency harmonics confusing the tuner.

[Brint Hannay]

At what point does the open string read higher? On the initial attack when the string is struck or after it has sustained for a second or so?

Though I can't explain the phenomenon in terms of the physics involved, the "twang" of an open string causes it to go slightly sharp initially, then settle down to the sustained pitch, while a harmonic played by placing a finger against the string at the twelfth fret (the half-way point of the string length) suppresses the full-length vibration of the string and reduces or eliminates that effect.

If the sustaining pitch is sharper than the harmonic, then I guess this wouldn't be the explanation!

Thick plain strings like a plain 6th on E9th tend to have slightly off-kilter overtones, so Bill's idea may apply, too.

[Paul E. Brennan]

Yes Brint, the string reads sharpest on the initial attack then it settles down a little. Your explanation makes sense to me. Do all steels behave in this manner or are some steels more prone to it?

Bill, this doesn't bother me as I only use the tuner to set my E strings. I tune the rest by ear. It took me a long time to learn to do this but I'm very glad I took the time to do it. Tom Brumley once told me that you should check your tuning by ear every time you sit behind your steel. He considered it an important part of learning to play. I'm just curious about this phenomenon that's all.

[Howard Tate]

In my opinion, when you hit the string with your pick you bend it a little making it go sharp, then it settles into back. I think that's the same thing Brint said. and of course when the string is halved at the twelfth fret the deflection is halved too.

[Erv Niehaus]

ALL strings will show sharp when initially picked.
They settle down after a brief period.

[Earnest Bovine]

The open string reads higher than the 12th fret harmonic. This happens to a lesser extent on the other plain strings. Does anyone have an explanation for this phenomenon?

Yes, this phenomenon is called inharmonicity.

In an ideal perfect string, the frequency of each partial (harmonic) is an integer multiple of the fundamental. For example the A (5th) string on a standard guitar has a fundamental frequency of 110 Hz. If it were a perfect ideal string, it could also vibrate at 220, 330, 440, 550 etc Hz.

But perfect strings exist only in elementary textbooks. The difference between those perfect harmonics and real harmonics is called inharmonicity. It is caused by stiffness of the string and the way it is anchored at the ends. A stiff A-string might vibrate at 110, 221, 333, 446, 558, or something like that (I'm exaggerating; a real string would usually would be closer.)

You can see inharmonicity on a strobe tuner where there is a separate band on the wheel for each partial. You can get one to stand still, but the other partials may move to the right or left. You have to decide which partial(s) are more important, and tune to those. A tuner with just a needle probably uses some sort of average. Your ear would probably do better.

If it seems worst on your G# string, that's probably due to stiffness because it has a higher ratio of diameter to length.

(edited the typo: A is 110 Hz, not 100 Hz).

[b0b]

I think it happens more with old strings.

[Greg Vincent]

(EB I think you mean to say that the 5th-string "A" has a fundamental frequency of 110 Hz.)

As I learned from Mr. Bovine several years back, inharmonicity is why pianos have to have their tunings "stretched". All stringed instruments suffer from it, but a piano's wide range of frequencies makes it a bigger problem --hence the "stretching" solution.

-GV

[Paul E. Brennan]

Earnest, thank you for that information.

Bob, Guilty as charged. I leave my strings on for far too long. Except for the high G# sharp. That one tends to remind you when it needs to be changed!

[Donny Hinson]

I've also noticed it more with old strings, as Bob mentions. The strings wear down more below the 12th fret, where we do the most sliding of the bar. This leads to a condition where the string has less mass on the lower end, which can lead to minor tuning and harmonic problems.

[Jon Light]

More times than I can count, I have battled with getting a particular string in tune, never being able to get rid of some beats. And then a bit later (after giving up and trying to ignore the bad sounding string) the string breaks. And I say, yet again, "oh yeah, I should have remembered from the last time that a string that used to sound ok but that starts to get warbly is probably telling me that it's time for a change....I'll remember for sure next time"." And of course I will.

[Don Brown, Sr.]

Putting on a new set of strings will cure (in many cases) a whole lot of different symptoms that might otherwise occur from strings left on too long. "It's always a good starting point."

[Bo Legg]

I have found that the problem may be in using that plain 20 on the 6th string (G#).
I haven't been able to use a plain 20 on any of my Sho-Buds.
That plain 20 don't fret true anywhere on the neck, so how could I expect it to be true when I chime it at the 12th fret.
There is something screwy about that plain 20 anyway because I can tune it to the tuner and it sounds way off to my ear. In other words the tuner is hearing different harmonics than I am.
What seems to be proof of this for me is that I can put a wound 21 or 22 and almost never have a problem with that string.
I'm sure I'm going to hear that everybody uses a plain 20 and have no problems with it.
Whether you think the string is screwed up or my ear is screwed up doesn't change the fact that the wound string will solve the problem for me.

[Erv Niehaus]

Bo,
Try a plain 22 string.
That's what I'm using.
I would like to go with a wound string but I drop it to F# so have a hard time doing so with a wound string.

[b0b]

I'm with Bo. Those thick plain strings .020 or .022 never sound right to my ear.

[Roger Crawford]

On a Peterson tuner such as the Strbo-Flip, would one of the bands on the wheel be better than another, or would it change from string to string?

[Pat Comeau]

I'm having the same problem as Bo and B0B , it seems to be flat to my ear on the 12th fret but right on on the tuner, i also think there is something really weird going on with the plain 20 or 22 gauge string but i like the feel and it sound better then the wound 20 string.

[Brint Hannay]

I agree that both plain .020 and .022 have inharmonicity that sounds a little funky (see Earnest's explanation above), but as someone who greatly values the whole-step lower on string 6, I have to live with it. As it happens, I recently put a wound .022 on one of my guitars, just as an experiment to see how the tone compared, and while it didn't have the odd intrinsic beats, I didn't care for the tone. To each his own!