Intonation Issue

[k_russell]

So I replaced the nut, saddle, and bridge pins on my Guild D40c (built in 1979). I made an adjustment to the truss rod, the string height at the nut was good, and I filed the saddle to a favorable action. All worked fine.
Because I have another dreadnought that I can use for bluegrass, I decided to string this D40c with Martin M1400 Silk & Steel (.0115 - .047). I set up the guitar using D'Addario EXP 17 (.013-.056). I wanted a more folk song kind of sound.
I can play the guitar comfortably with the M1400's but my intonation is off. At the 12th fret, the notes play sharp. I tried another set of M1400 and I'm still sharp.
The intonation is fine up to the 7th fret. I rarely use notes higher for the songs that I play on this guitar.
Do you think that I can make some adjustments to the saddle to correct the intonation? I'm not going to get much help (relief) from adjusting the truss rod. I'd like to postpone a neck reset, if possible. The 12th fret notes are only a few cents high (just high enough to be detectable by ear). Currently, the guitar suites my purpose, but I would like to correct the problem.

[ljguitar]

Originally Posted by k_russell

So I replaced the nut, saddle, and bridge pins on my Guild D40c (built in 1979).

Do you think that I can make some adjustments to the saddle to correct the intonation?

Hi k_r
Given you've adjusted height at the nut, and if the curvature of the fingerboard (truss rod adjusted properly for low action without buzz) then then compensating the saddle is the next step.

I think simple adjustment at the saddle is your best option for what you've talked about.

For me, intonating the saddle (electric or acoustic guitars) is the cherry-on-top-of-the-sundae which pulls those ornery octaves into tune.

I prefer to adjust those at the saddle rather than the nut because I use capos and partial capos a lot. I've always suspected if intonation is adjusted at the nut & I capo that I'm negating the change.

I've never played with that to know for sure. There are intonation solutions which adjust string length at just the nut (Ervana nut company for instance)…or Feiten which compensates saddle and nut..

Buzz Feiten's system adjusts between nut and saddle changes, but when I've played these, they are no better than just adjusting the saddle. All adjustment systems tend to just shift the out of tuneness to less played spots on the finger board.

It's by far the cheapest option (far cheaper to replace a saddle versus a neck reset). Even if you reset a neck, you still need to set the curvature of the fingerboard, height at the nut, height at saddle and lastly compensation for intonation.

I think simple adjustment at the saddle is your best option for what you've talked about.

[Buc-a-Roo]

String gauge can make a huge difference in the accuracy of intonation. I will guess that this was not an issue with the .013-.056 set. Now you've gone down to .011-.047.......huge difference. To keep the lighter gauge you may well have to have a saddle custom sculpted to get the intonation back where you want it. I do not believe any other adjustments such as nut height, saddle height nor t-rod tweaks will make any difference in what you're hearing.

[k_russell]

Originally Posted by Buc-a-Roo

I will guess that this was not an issue with the .013-.056 set.

The intonation is spot on with the .013-.056 set. I'm going to attempt the saddle adjustments myself. Wish me luck. I will hire a qualified technician if I get in over my head or see signs that I might be damaging the guitar.

[CarolD]

Originally Posted by k_russell

The intonation is spot on with the .013-.056 set. I'm going to attempt the saddle adjustments myself. Wish me luck. I will hire a qualified technician if I get in over my head or see signs that I might be damaging the guitar.

Maybe keep the saddle for when you want to string it with 13/56 and buy a second saddle for the other strings. That way you always have at least one you know is good.

[k_russell]

Originally Posted by CarolD

Maybe keep the saddle for when you want to string it with 13/56 and buy a second saddle for the other strings. That way you always have at least one you know is good.

Good plan, thanks - I have another saddle that I plan to use for this project.

[charles Tauber]

Originally Posted by ljguitar

All adjustment systems tend to just shift the out of tuneness to less played spots on the finger board.

If you measure the out-of-tune-ness of each fret for a single string, then plot those measurements, you will have some best-fit line that goes through the points for that string.

Typically, the curve will have some slope and will not pass through zero error. Adjusting the vibrating string length at the saddle (saddle compensation) changes the slope of that curve. Ideally, one wants to alter the slope so that the line is horizontal. Doing so indicates that each note is a constant amount out of tune.

Adjusting the vibrating string length at the nut (nut compensation) changes where the curve crosses the Y axis (amount of error in cents). Ideally, one compensates the nut until the curve crosses the axis - the abscissa - at zero.

In theory, if one does both of those, one ends up with a constant amount of error at each fret that approaches zero: one approaches "perfect" intonation. Doing so does not shift the out of tune-ness around.

Intonation - how accurately an individual instrument is able to achieve the target pitches - should not be confused with temperament - the system being used to define the target pitches. Most guitars are designed to use equal temperament.

Equal temperament is a compromise and will not sound in tune to most people. To deal with that compromise, many people will "sweeten" the tuning to get it to sound more in tune. That does, as you said, simply move the out of tune-ness around. That should not be confused with intonation or the compensations that are made to improve intonation. Even a guitar that has perfect intonation - if such a guitar existed - would still sound out of tune to most people.

[Alan Carruth]

It would be hard to add much to Charles' excellent (and brief!) post. Resonances of the guitar that are close to played notes can react back on the strings to shift the pitches, and that's one reason you will seldom achieve 'perfect' intonation on a guitar. The more responsive the guitar is the more likely it is to have these issues. Makers can 'tune' these out to some extent, but they're inherent in the guitar. They can also shift around with changes in humidity, and become problematic 'wolf' notes.

[rick-slo]

The lower tension of those Martin M1400 Silk & Steel (.0115 - .047) strings is resulting in increase inharmonicity of the upper partials. Best bet is to pick out a set of strings the have higher tensions when tuned up.

[k_russell]

Originally Posted by rick-slo

The lower tension of those Martin M1400 Silk & Steel (.0115 - .047) strings is resulting in increase inharmonicity of the upper partials. Best bet is to pick out a set of strings the have higher tensions when tuned up.

That's what I suspect. I'm not sure that any modifications to the saddle will help much.

[ljguitar]

Originally Posted by k_russell

That's what I suspect. I'm not sure that any modifications to the saddle will help much.

Hi k_r

I can only report on my guitars. I have three handbuilt guitars with a good heritage, and both wear .011-.052, and I bump the 1st string to a .012.

The compensation for intonation is just as detailed on them as on my other two gutiars which are .012-.056 strings.

I would suggest at least compensating a saddle to see if it's going to help.

I'll post a picture of the compensation on my Olson which is an above-average in-tune instrument (thanks to my luthier, Michael Bashkin). The other guitar I mentioned is my Bashkin OM - fanned fret (25-25.75") which can even wear .010 strings if needs be.

At the time it was built, I was going through some wrist restrengthening issues, and it was built to be able to handle very light strings.

Here the saddle of the Olson…

At the time I had this saddle custom built by Michael Bashkin, the Olson was just over 20 years old, and the bridge had tilted enough forward the low E would no longer play in tune (several cents sharp at the octave). Enough to distract me at times…

So Michael filled the slot, recut then slot slightly deeper, and moved the bass end back nearly 2mm. Using the thicker saddle he intonated the 6th string all the way toward the tail, and it now plays in tune if I'm careful to not over-press on fretted notes (took me ½ week to adjust my touch down on bass notes).

I heard all the speculations from people as to whether restating the bridge was worth it. I went ahead with it, and t was worth it.

All I'm suggesting is you never know how much things change unless you try. And it probably depends on whether it's important enough to seek correction. Luthiers and set-up techs are amazing and worth seeking out.

[Inyo]

Originally Posted by k_russell

So I replaced the nut, saddle, and bridge pins on my Guild D40c (built in 1979).

I made an adjustment to the truss rod, the string height at the nut was good, and I filed the saddle to a favorable action.

My intonation is off. At the 12th fret, the notes play sharp.

The intonation is fine up to the 7th fret. I rarely use notes higher for the songs that I play on this guitar.

The 12th fret notes are only a few cents high (just high enough to be detectable by ear).

That sounds exactly like the infamous misplaced bridge issues reported on some 70s Martin dreads, creating poor intonation (slightly sharp, mainly) at the 12th fret.

[TedBPhx]

Originally Posted by Inyo

That sounds exactly like the infamous misplaced bridge issues reported on some 70s Martin dreads, creating poor intonation (slightly sharp, mainly) at the 12th fret.

My ‘79 D-35 has that issue. Martin paid for a neck reset but that, while making the action great, did not fix the intonation issue. Still debating if it’s worth getting a new bridge. Meanwhile I’m loving the Taylor 814ce V.

[k_russell]

Originally Posted by ljguitar

Hi k_r

I can only report on my guitars. I have three handbuilt guitars with a good heritage, and both wear .011-.052, and I bump the 1st string to a .012.

The compensation for intonation is just as detailed on them as on my other two gutiars which are .012-.056 strings.

I would suggest at least compensating a saddle to see if it's going to help.

I'll post a picture of the compensation on my Olson which is an above-average in-tune instrument (thanks to my luthier, Michael Bashkin). The other guitar I mentioned is my Bashkin OM - fanned fret (25-25.75") which can even wear .010 strings if needs be.

At the time it was built, I was going through some wrist restrengthening issues, and it was built to be able to handle very light strings.

Here the saddle of the Olson…

At the time I had this saddle custom built by Michael Bashkin, the Olson was just over 20 years old, and the bridge had tilted enough forward the low E would no longer play in tune (several cents sharp at the octave). Enough to distract me at times…

So Michael filled the slot, recut then slot slightly deeper, and moved the bass end back nearly 2mm. Using the thicker saddle he intonated the 6th string all the way toward the tail, and it now plays in tune if I'm careful to not over-press on fretted notes (took me ½ week to adjust my touch down on bass notes).

I heard all the speculations from people as to whether restating the bridge was worth it. I went ahead with it, and t was worth it.

All I'm suggesting is you never know how much things change unless you try. And it probably depends on whether it's important enough to seek correction. Luthiers and set-up techs are amazing and worth seeking out.

I plan to work on the saddle, if for no other reason, than to see what happens. If I fix the intonation problem, all the better. Thanks for your help.