Intonation problems (how precise should intonation be?)

[archerscreek]

If I had a high quality guitar I would expect essentially perfect intonation. I have two quality Martin guitars. Tune the open string. Fret notes up the neck. Everything is spot on.

I have had lesser quality guitars in the past. Took them in for a setup. Intonation was never perfect. Quality of build makes a difference, regardless of whether or not the saddle is compensated. Tolerances are not as tight with lower quality guitars. Close enough is good enough, and some people can hear the difference.

[Howard Emerson]

Originally Posted by jonathanemra

I had it set up exclusively to improve intonation, and even though its gotten better by a few cents, I'm disappointed that its not perfect. The string gauge is the same as before, everything else is really. I'm just not noticing a huge improvement, which is what I hoped for

Hi Jonathan,
What are the chances you could post an audio/video playing the guitar and a piece that audibly demonstrates the issue, in context? That would be incredibly helpful in trying to help you get a grip on the issue.

Now of course if its that you're not happy with what your tuning machine is saying, that's not applicable here.

If I went by what my electronic tuner said I'd never be able to start playing my guitar. I use it to get in the ballpark, and then tune by ear so that my compositions play in tune, in all of their sections, in any of 5 or 6 tunings that I use.

Regards,
Howard Emerson

[guitar george]

If a guitars frets were installed slightly incorrect, would that make it impossible to achieve perfect intonation?

[ljguitar]

Originally Posted by jonathanemra

…How precise should It be? I know by now that my ear is a bit more trained than most (dad is a jazz pianist), but I feel like after paying good money to have it set up, it should be spot on.

Hi j…
Not all setup techs intonate the saddle well. Intonation is a mixture of action (string height off the neck), precision customization of the saddle, and compromise…because the tuning system of the guitar (and most other fretted and strung keyboards) is a averaged system so we can play our instrument in all 12 keys.

It's called Equal Temperament. I'd change strings 1-2 on your guitar before taking it back to be adjusted (those are the ones you reported as playing flatter the higher you play). If they are wearing out, they may improve with fresh strings. If not, then you know it's an issue to be addressed by the tech.

In fact when I need intonation set properly on a guitar, I specify it and pay the tech extra…and ask that it be as close as possible. As my main guitar aged, it even required filling a saddle slot, and moving the bass end of the saddle slot back a couple millimeters and the re-adjusting (carving/sanding) the top edge of the saddle to properly intonate the bass notes when fretted.

How precise it should be will depend on your tolerance to the out-of-tuneness your guitars play at, and how well they can be adjusted if necessary, and often that all happens after the guitar action is set. And intonation should be done with fresh strings, the weight you normally play.

Worn strings play out of tune. So if you play a lot in alternate tunings (like DADGAD) it's good to have the guitar tuned to the alternate tuning, with the weight of strings on it which it will be played with.

I play more than 50% of the time in Dropped D, so all my guitars have the 6th string intonated while tuned to low D.

And realize, tuning is a compromise. I hear smaller gradations of pitches (cents are ¹⁄₁₀₀ of a half step) than my luthier. He uses a very sensitive tuner when intonating guitars (not just for me, but for all his clients).

Hope this 'helps'…

[charles Tauber]

This subject comes up fairly often. As ljguitar pointed out, there are two unrelated things at play.

The first of these is "temperament" and defines what are the target pitches an instrument (or voice) aims to achieve. The second is "intonation", which is how closely an instrument achieves the target pitches.

By a large margin, most guitars are designed to equal temperament - the frets are placed to achieve that. Most people do not hear equal temperament as being "in tune", instead preferring Just tuning. Equal temperament is a mathematical construct aimed at making all notes/keys sound equally in tune and out of tune: it allows one to change keys without being "unacceptably" out of tune.

Practically, for a guitar, intonation has to do with how accurately your instrument is designed and setup to achieve the pitches defined by equal temperament. It is possible to design and setup a guitar to be within 2 cents of the target pitches across the entire instrument's range. Most acoustic guitar players do not demand that of their instruments, the consequence of which is very few guitars achieve that "out-of-the-box". It is possible, with the right knowledge and skill, to setup most guitars to very closely achieve the target pitches (i.e. equal temperament). Whether the average "tech" is willing or able to do that is a different issue.

[Alan Carruth]

As Charles notes, guitars in general are designed around 12-tone Equal Temperament. One reason for this is that it's the only scheme where all the semitones are the same size, which means that all the frets can be straight. ET has problems, and once you start to notice them they don't go away.

One thing that can mess up intonation is the interaction ('coupling') between strong resonances of the air or top and the motion of the string. In theory the end of the string should be 'fixed' if it's to make the proper pitch. However, if the top of your guitar didn't move it would not make any sound. Movement of the top can fool the string into thinking it's longer or shorter than the distance from the fret to the saddle. The top/air resonances that cause the problem happen at specific pitches, and those are the ones that are thrown off. You can set the intonation up 'perfectly' at the 12th fret, and some other pitch can be out of whack. Getting the intonation to be as close to 'perfect' as possible can require some adjustment of the top resonances, and maybe others as well.

In general, intonation issues are caused by the fact that you have to stretch the string in order to fret it, which raises the pitch. Since you stretch the string at both ends it usually needs some sort of compensation at the nut as well as the saddle. Again, Gore is the go-to guy on that.

[Bruce Sexauer]

From a practical standpoint, most people really don’t hear a less than 3 cents discrepancy, and on ANY GUITAR I draw the line at around a 5 cent discrepancy of the first octave harmonic relative to the same note fretted at the twelfth fret. My own guitars are generally within a cent or two on all strings when new and with fresh strings. Even at 5 cents I have trouble convincing myself that the guitar is in tune . . . ever. Many guitars I see on my bench fail to pass this test.

[Steadfastly]

Guitar design often is the reason we can't get precise intonation. Changing the saddle to a variable one might help. Here is a link to a thread discussing it.

https://www.acousticguitarforum.com/...d.php?t=236467

[Graham H]

Not all setups are created equal. The way I do mine, and I have done a lot of research on this for my electrics and acoustics, I always use brand new strings. The first thing I do is check the relief on the neck. I want my necks to be as flat as possible, this involves adjusting the truss rod to get the relief where I want it, very little relief, so you need a set of feeler gauges to make sure you are spot on. Then I check the nut and the string slots with a capo at the second fret, to make sure they are at the correct height, if the nut isn't cut properly, you need to fix it, and make sure the radius is correct. Then I check the height at the 12th fret on the low E and then the high E to get an idea if the saddle might need to be adjusted and to make sure the action is where I like it. I also check the radius of the bridge saddle to make sure that the saddle is correct. I check the tuning open, then at the 12th fret on the string, fretted and then the harmonic, and if they all match you're good to go. It takes a lot of practice to get it right, but this is what you need to ask your tech to make sure he does it right. The hardest parts are getting the bridge saddle(on an acoustic some saddles need to be compensated and some electrics have the tunomatic bridge with the individual saddles to adjust)) and the nut done correctly!!! It involves a lot of time and effort to be done correctly !!!

[tadol]

If the saddle is not in exactly the right place, getting intonation right can be a real problem. With many basic setups, a luthier may try to get the intonation as close as they can within reasonable effort, but filling and re-routing a saddle, or installing a wider saddle, is a much more involved job. If the intonation is off and bothers you, go back to your setup person, play it so they can understand what you are hearing, and see what options they can offer to make it better.

[YamahaGuy]

Once the frets are leveled and the saddle height and nut slots are the right depth, and the truss rod is adjusted, intonation can only by altered by the saddle angles and the nut. There are compensated nuts -- yes nuts, not saddles-- as well as compensated saddles. Lengthening or shortening the distance between the nut and saddle is how intonation is set, in addition to how hard the string is fretted. There is a physical limitation as to how much that length can be changed.
The low e string should be one of the easiest strings to get the intonation right with since the diameter of the string is larger it requires less of a change in that distance between the nut and saddle. I suspect your setup person pressed very hard when checking the intonation, and has set the break point on the saddle nearer to the endpin, which is common for most setups.
That said, if you paid someone to do it and they missed the mark, I'd take it elsewhere or kindly ask the tech to make it right.

[Mandobart]

Jonathan - I'd say you got a bad setup. I took my lowly 1970's Applause 6 string and early 80's Ovation 12 string in for saddle compensation about 15 years ago and my local tech got them both spot on, at least according to the various tuners I've used. One of the reasons most of my instruments have floating bridges - I can adjust intonation pretty easily for changes in string gage, weather, etc.

[musicman1951]

I don't know if it's your guitar or the set up, but I would find 5 cents out unacceptable. I'd take it back and see what your repair person says.

Intonation is a quirky enough can of worms to also have to deal with your guitar being out of tune with itself.

[Steadfastly]

Originally Posted by musicman1951

I don't know if it's your guitar or the set up, but I would find 5 cents out unacceptable. I'd take it back and see what your repair person says.

Intonation is a quirky enough can of worms to also have to deal with your guitar being out of tune with itself.

Yes, at least ask him if he can get it better and what he did to the guitar during his setup.

[Tony Burns]

as a few posts have stated - tonation can never be perfect with frets( thats a fact )

but if your not happy with the new set up -you should visit the person who did your tonation
-they should be able to get it closer with a small tweak here and their -