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How is it I can setup a guitar. Use a compensated bridge slot. Install a compensated saddle. Get it so that the 12th fret harmonic and the open string are almost identical in tuning. But when I tune up the guitar using a tuner, I up having to tweak the b string setting so that the D chord sounds correct. Or open E chord (E5). What am I not getting? I do use a saddle-matic to position the bridge and lots of other measurements.

Well it would help to use the open string and the fretted b at the 12th fret, not the harmonic.

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Jim Watts
http://jameswattsguitars.com

Chords on guitars are never totally in tune. That's how the even tempered scale is.


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Everyone's probably getting tired of me saying it, but... nut compensation. The alternative is to make compromises in tuning, which it sounds like you're doing.

The nut slots are likely too high. This is the message that we have been trying to help with here. When the nut slots are too high chords in the first few fret positions will be off. This has historically led back in the day to solutions for the symptom.... not the problem such as nut compensation.

When nut slots are properly cut and nice and low these kinds of issues disappear the vast majority of time.

The guitar is an equal temperament instrument and the best you can do to "tune" it is to have it play equal temperament accurately. Most guitars don't. But no guitar plays Just temperament accurately in all (or even any) keys, which it seems is what you're listening for, without having to tweak the tuning, usually by flattening the equal temperament thirds, which are 14 cents sharp of Just temperament thirds, which sound nicer. If you can get accurate equal temperament, learn to live with it, because that's as good as it gets and is the compromise we have to suffer for the ability to play in different keys all over the neck.

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Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

The G/B junction is simply the bastard child of guitars. As Trevor pointed to, open it would prefer to be a major 3rd, but we tell it no, you're going to have to be 14 cents wider. Play an Emaj, and it suddenly wants to pretend it's a minor third, but we make it spread 16¢ too narrow. Move to a C or D and now it can be a 4th interval which shouldn't be too bad, unless we already tried to tweak it to favor the role of a major or minor third. No solution will fix all these contradictory goals.

For good measure we throw this bastard third interval right in at the transition where plain steel strings are getting too stiff before switching to wounds, and intonation gets even more challenging. Cutting the nut slots to proper depth can help reign these issues in, and for some setups/styles a bit of nut compensation can be appropriate. Overcompensate too much to favor a chord like Emaj, though, and your Amaj will suffer to an equal and opposite degree of what you tried to correct.

What the right hand giveth, the left hand taketh away. Ideal solutions to this conundrum have evaded some of the top musicians, mathematicians, architects, and scientists for centuries. The best we can do without smart pitch correction software is bring it as close to in tune as possible in equal temperament, (typically resolved by cutting the nut slots precisely down to the fret plane), and avoid trying to tweak toward being truly in tune with pure intervals.

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Eschew obfuscation, espouse elucidation.

I have a bad musical ear..............if I get it close it sounds wonderful to me. Lesson learned??? A dud ear is a good thing and a bad thing......................a first class musical ear is a good thing and a bad thing.......!!!
Tom

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

Being the largest plain string, the B string has the lowest tension and relatively high bending stiffness. in other words, fretting it will pull it sharp more than the e or G strings.
The same trouble arises with the G string on classical guitars.

I guess I am fortunate in that I learned that fact when I was very young. I have spent the rest of my 61 years trying to explain it to those who have problems with tuning.

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John

John Arnold wrote:
"Being the largest plain string, the B string has the lowest tension and relatively high bending stiffness. in other words, fretting it will pull it sharp more than the e or G strings."

It's not the stiffness of the string that causes it to go sharp when fretted. Tuning the B string up to E would give you about the same pitch change with bending as you see with the E. The stiffness of the string has not changed, just the relationship between the starting tension and the tension change on bending.

Basically, the tension change when you fret the string is proportional to:
E * a *(delta L/L), where
E = Young's modulus
a = the cross section area of the string
delta L = the change in length and
L = the initial length.

In most string sets the B string carries only a little more tension than the high E, but it's about 40% larger in diameter, so it has something like twice the cross section area. The Young's modulus is the same, and so is the length change term, so the upshot is that the B string sees about twice as much tension change as the E for a given displacement, and undergoes a larger pitch shift.

On reason it's easy to get hung up on stiffness as a variable is that the B string is so much stiffer in bending than the E. Bending stiffness goes as the fourth power of the diameter, so the that 40% of added diameter should make it 16 times as stiff. That doesn't so much affect the pitch shift with displacement as it does the inharmonicity: the stiffness shifts the higher partials upward in pitch as the string gets to acting more like a bar than a string. Thus pitch shift with displacement does go hand in hand with stiffness to some extent, but its sort of a red herring.

A lot of you already know this but some may not:
Even with a well setup guitar, there is more to guitar tuning then just hooking up a tuner and trying to get each string exactly on each note. I play in a group with piano and wind instruments and several times a year we perform with a string section too. If I'm not tuned right it sticks out like a sore thumb. I find the B and low E strings to be the most difficult and often have to retune them during a performance so that certain notes up the neck will be correct. Bottom line is there is no way you will get the guitar setup so it plays perfectly in tune for everything.

It's well known that the human ear will tolerate a note that is slightly flat much better than a note that is slightly sharp so I take advantage of that when I tune. And none of the strings are tuned to the exact note although the G is pretty close.

James Taylor has video that shows how to do this and the numbers he provides at the end work well.
https://www.youtube.com/watch?v=V2xnXArjPts

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Steve Smith
"Music is what feelings sound like"

Fascinating. I can go a bit deeper on the B & High E. That should help a bit. I thought I was suffering a systemic problem, but then I tested a Gibson Jumbo and a Taylor 810 and they demonstrated the same problem (to varying degrees). Watching JT made me realize I wasn't alone (or crazy).

Thank you!

For the record, the videos I watched on this issue discussed using the harmonic.

I question using the open compared to harmonic as well. Part of intonation is to account for the difference in length for a string between a fretted note and an open note. An open note note compared to a harmonic does not show that difference. I can understand comparing a harmonic to a fretted or an open to the fretted.

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http://www.Harvestmoonguitars.com

Surely an open note and a harmonic will always be in tune with each other, give or take string wear and manufacturing tolerances, won't they? The harmonic simply sets up a standing wave that divides the string into equal sections, no matter what length the string is or what pitch it's tuned to.
As for the B string discussion, I'm just glad I have terrible pitch recognition!

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"I am always doing that which I cannot do, in order that I may learn how to do it."
Pablo Picasso

https://www.facebook.com/FenskeGuitars

I agree. I have an Earvanna nut on one of my guitars, and it makes those pesky open chords sound nice!


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Many new guitars these days are not set-up and with the availability of these brands from Internet resellers they often have never been touched since they left the factory. As such the set-ups we see on commercially available guitars are often horrible.... and nothing to gauge anything against other than perhaps the word horrible... If these two had the same issue it's because of the same problem, unaddressed, nut slots too high.

When fretting and holding between the 2nd and 3rd fret and tapping the string on top of the first fret for the high e and b the space between the string bottom and the 1st fret crown should be very nearly imperceivable visually. Instead we may hear a "tink" sound and if we hear nothing the string could be too low and in contact with the fist fret. Dave describes what he sees as a bending of light or sliver of light. I can't see that....

This is the dicey part of cutting some nut slots particularly the high e, b, g where we want and benefit from as low as we can go but at times as Tai Fu recently said in another thread that optimal distance may be one file swipe away from going too low. That's exactly right too, one file swipe from going too low is often the case.

The idea is that the lower the nut slots are cut when properly cut the less the string has to bend to make contact and the less it's pulled sharp. When done correctly, and everyone here is capable of doing this correctly with some practice, nut compensation is not necessary and again a method of addressing the symptom, too much stretch needed in the string because of high nut slots and not the root problem.

F*ctory set-ups suck with of course some exceptions from smaller producers because to do a really good set-up on an acoustic guitar it requires skilled labor. Skilled labor can cost more....

Back in the day producers relied on dealers to do the final set-up but these days, sadly, most new guitars are sold having never been properly set-up. Customers often struggle for a year or more until someone else tells them that their set-up sucks and then they come see Luthiers. We see this every single day.

It's good for our business but bad for players and what ever is bad for players is likely bad for all of us in the long run. But you know what they say about the long run....

Hesh, I agree that high nut slots can be an issue but I can guarantee that the nut slots on my daily player are not high but are almost too low to "tink", relief is almost flat at about 0.005" and 12th fret action is right around 4/64, 6/64. I am sure there is more that could be improved on the neck but I have observed this with more than one guitar. I'm looking forward to the opportunity to explore this further when I come up this spring; I would love to eliminate the need to retune between certain songs.

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Steve Smith
"Music is what feelings sound like"

It seems to me that the nut slots need to be just a bit higher off the fretboard than the first fret, to avoid back buzz. At any rate, no matter how low you get them fretting the string at the first fret will cause it to go a bit sharp, so some nut compensation is still in order. Usually.

The problem with using string 'harmonics' to tune is that they may not be really harmonic. The seventh fret 'harmonic' is, of course, not the correct pitch in equal temperament even if it's 'right'. Theoretically, the seventh fret harmonic on the A string should be 3 * 110 Hz, which is E at 330, but the correct frequency for the E in ET is 329.6 Hz. If the A string has some stiffness that will tend to shift the 'harmonic' pitch further up, and it's already too high. Even the 12th fret octave harmonic can be shifted up a little. Not only can string stiffness shift things, but so can wear, or loading from crud in the string winding. It's usually better to compare the fretted and open notes to see if they're an exact octave apart.

It's probably impossible to get all the notes on an acoustic guitar to be perfectly on pitch. OTOH, most other instruments have similar problems for various reasons. Small pianos are terrible, so I always get a laugh when people tout some guitar setup by saying it makes the guitar 'play in tune with a piano'. It's the equivalent of saying 'these shoes will make you run as well as somebody in shackles'.

We compared an Earvana nut with a plain one at a local luthier's meeting once. From what I could see the results with each of them were about equally 'off', but in different ways. Maybe the proprietary nut gets the usual guitar keys too sound better, but it didn't seem to improove the intonation overall with reference to ET.

Did you/could you move the saddle break points equally closer to the 12th fret along with it? If not, then that would make sense to be out of tune in the opposite direction.

I honestly don't remember all the details; it was several years ago. Iirc, the bridges in each case were adjusted to get the 12th fret intonation to be as close as possible. Notes further down the neck were off in various ways according to the tuner, and it seemed to be pretty much a wash to me.

I did the full blown nut compensation from Gore\Gilet book and had much better intonation (measured with a strobe tuner) on all the strings and open through 12 fret (I did not check the rest). I believe that it is a better distribution of errors rather than less error total. The intonation was noticeably better in the first four positions vs. standard 12th fret intonation.

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http://www.Harvestmoonguitars.com

I did a little test this morning. I fretted the high e at fret 2. I tried pressing harder to change tone. Could not really make a difference. The b string however, totally different. I never noticed that before (other than capo issues).

For the record, the videos I watched on this issue discussed using the harmonic.


I learned many years ago,
open, fretted 12th, 12th harmonic.
Always worked for me.
Also, I want to add,
when I tune my lapsteel git box,
say in D, DADF#AD,
the F#, or 3rd,
is always tuned flat, by quite a bit,
one notch flat by my peghead clip on tuner.

The problem with comparing the open string and the 12th harmonic (as opposed to 12th fretted) is that the harmonic will always be pretty close to in tune regardless of minor saddle position errors. This will NOT guarantee that the fretted notes in this region play in tune.
Back before electronic tuners we would play the harmonic then the 12th fretted note and compare by ear for setting intonation.
These days I believe you get a better result by tuning the open and then playing the 12th fret and not bothering with harmonics.

But the problems in the "cowboy chord" region are as others have said, more to do with nut slot height, Nut compensation or the lack thereof, and the nature of 12 tone equal temperment