Low E Intonation

[guitar2005]

I'm getting a weird problem on my guitar.

I've done the intonation and it seems to be fine except on the low E string. I set the intonation at the 12th fret but when I fret a G on the 3rd fret, its almost 10cents out of tune (sharp). The first couple of frets are also sharp but only for the Low E. The other strings are allright.

Any clues? The nut looks fine to me but maybe there's something subtle I'm missing.

Edited December 16, 2008 by guitar2005

[bluesy]

I'm getting a weird problem on my guitar.

I've done the intonation and it seems to be fine except on the low E string. I set the intonation at the 12th fret but when I fret a G on the 3rd fret, its almost 10cents out of tune (sharp). The first couple of frets are also sharp but only for the Low E. The other strings are allright.

Any clues? The nut looks fine to me but maybe there's something subtle I'm missing.

My theory

If the string is not sitting properly in the nut slot, e.g. if it's last point of contact is not right at the bridge side of the nut, then this can happen. When this happens, the first fret is effectively too long. Let's say the string is actually only touching the nut at the headstock edge, the first fret is effectively increased by the width of the nut material, hence all notes will be sharp compared to the open string, and it will be more noticeable on the low frets.

Also, too high an action, means the string stretches when you fret it, and this also sharpens the note.

[egdeltar]

Bluesy is on the right track. I would measure your first couple of frets also to insure your scale length is 100% correct.

[Prostheta]

I'm sure the scale length is fine if the other strings intonate. As mentioned, the nut is the first potential issue to examine.

[Acousticraft]

A pretty common problem the thicker strings being sharp at the first few frets. I read just recently of some Luthiers that tune at the 5th fret and intonate at the 17th to even out the tuning errors over the fret board. I havent tried it but will give it a go next time I do a string change. I guess Capo the 5th and tune to A-D-G-C-E-A and set intonation at 17th.

That the reason they brought out Earvana nuts that are supposed to help correct those intonation problems. A guitar is a tempered scale and never plays exactly in tune over the whole finger board.

[bluesy]

A pretty common problem the thicker strings being sharp at the first few frets. I read just recently of some Luthiers that tune at the 5th fret and intonate at the 17th to even out the tuning errors over the fret board. I havent tried it but will give it a go next time I do a string change. I guess Capo the 5th and tune to A-D-G-C-E-A and set intonation at 17th.

That the reason they brought out Earvana nuts that are supposed to help correct those intonation problems. A guitar is a tempered scale and never plays exactly in tune over the whole finger board.

I like that idea. I will try it myself.

Although, this whole compromise tuning thing has just given me something to obsess about all the time. I need to clear my head and just play some music instead of worrying about inadequacies of the instrument's tuning and the equal tempered scale. I constantly hear 3rds that aren't so sweet anymore and have grown to hate that open C chord

[guitar2005]

I'm sure the scale length is fine if the other strings intonate. As mentioned, the nut is the first potential issue to examine.

Exactly... but I did measure the scale length before installing the fretboard.

Action is low.

I'll double check the angle on the nut.

[guitar2005]

I constantly hear 3rds that aren't so sweet anymore and have grown to hate that open C chord

I know what you mean... but this one is driving me crazy. All the other strings are fine, its just the low E. ArgghghgH! I thought it was fine a couple of months ago. It seems that this just kinda developed over time.

[RAI6]

Did you just replace the strings?

You may simply have a bum string.

This could happen to an old string as well.

It's pretty pointless to try to intonate a guitar using old strings....

[Mickguard]

Also, too high an action, means the string stretches when you fret it, and this also sharpens the note.

The answer's probably right there -- the nut slot isn't deep enough.

[dugg]

Yes, nut slot isn't deep enough. That's it for sure, don't bother to think about scale length or anything else, just file that slot. I check it with finger pressure. If I hold the string down on the first fret, then use another finger to press the string down on the second fret while still holding the back side down, that's the amount of finger pressure I should feel when pressing down at the first fret. Any more pressure felt will be extra tension added, sharpening the note. This is a better method than measuring string height because when it comes to sharpening notes near the nut, it's the tension (which varies with string guage) that counts. I doubt you made an error in nut placement, I'm betting it's the height of slot.

[RAI6]

How could the nut slot become more shallow over time?

He said it used to intonate, but not now...

[snarble84]

I have been having basically the same problem. This has helped me and given me some more ideas of what it could be.

Thanks

[bluesy]

How could the nut slot become more shallow over time?

He said it used to intonate, but not now...

I just reread it and I think he said he set the intonation on the 12th fret, but on one string only, it's sharp on the 3rd fret.

[guitar2005]

How could the nut slot become more shallow over time?

He said it used to intonate, but not now...

I just reread it and I think he said he set the intonation on the 12th fret, but on one string only, it's sharp on the 3rd fret.

Sorry... The fretted "G" is out but the other frets are out too. 1st fret to 5th fret are the worst ... so its not JUST the 3rd fret.

Strings are older so that could be it too.

Edited December 17, 2008 by guitar2005

[bluesy]

How could the nut slot become more shallow over time?

He said it used to intonate, but not now...

I just reread it and I think he said he set the intonation on the 12th fret, but on one string only, it's sharp on the 3rd fret.

Sorry... The fretted "G" is out but the other frets are out too. 1st fret to 5th fret are the worst ... so its not JUST the 3rd fret.

Strings are older so that could be it too.

Yeah, that's right, but the important bit is that the other strings are OK and this hasn't just started happening on a guitar that was working fine originally.

[guitar2005]

How could the nut slot become more shallow over time?

He said it used to intonate, but not now...

I just reread it and I think he said he set the intonation on the 12th fret, but on one string only, it's sharp on the 3rd fret.

Sorry... The fretted "G" is out but the other frets are out too. 1st fret to 5th fret are the worst ... so its not JUST the 3rd fret.

Strings are older so that could be it too.

Yeah, that's right, but the important bit is that the other strings are OK and this hasn't just started happening on a guitar that was working fine originally.

I played around with the nut. I think that when I originally made the nut, I may have cut the nut slot at the same angle as the headstock.

I did two things:

1- Changed the angle of the nut slot so that it is not as angled

2- Deepened the slot ever so slightly as a result of the above.

The fretted notes in the first couple of frets are much better. They only seem to go off by 5 cents with moderate pressure. Still not prefect but much better.

Does that sound reasonable?

[bluesy]

I played around with the nut. I think that when I originally made the nut, I may have cut the nut slot at the same angle as the headstock.

I did two things:

1- Changed the angle of the nut slot so that it is not as angled

2- Deepened the slot ever so slightly as a result of the above.

The fretted notes in the first couple of frets are much better. They only seem to go off by 5 cents with moderate pressure. Still not prefect but much better.

Does that sound reasonable?

I have read that an angle about half of the headstock angle is about right. I don't think it is critical, but it's important that the string is sitting flat in the bottom of the slot. I used to try to adjust nut slots with all sorts of implements, and had problems, until I bit the bullet and purchased a set of 8 nut files. Expensive but worth it. (of course if you are already using nut files, ignore me )

So, making the slot deeper helped? Then that begs the question, how much lower can you go? I forget the figures quoted, but one rule of thumb was that you should barely be able to get a piece of paper under the string over the 1st fret, when you are holding the string down at the 3rd fret.

[guitar2005]

I have read that an angle about half of the headstock angle is about right. I don't think it is critical, but it's important that the string is sitting flat in the bottom of the slot. I used to try to adjust nut slots with all sorts of implements, and had problems, until I bit the bullet and purchased a set of 8 nut files. Expensive but worth it. (of course if you are already using nut files, ignore me )

So, making the slot deeper helped? Then that begs the question, how much lower can you go? I forget the figures quoted, but one rule of thumb was that you should barely be able to get a piece of paper under the string over the 1st fret, when you are holding the string down at the 3rd fret.

Yup - got some nut files from Stew-Mac. I had to because I had an LP nut to do, a commissioned guitar plus one guitar for myself. All with bone nuts.

The angle that is between the headstock angle and fretboard seems to work best. I'm fairly new at cutting nuts so I'm still learning. I think that part of the problem may have come from the fact that the string was not properly seated in the nut at the fretboard side.

As for how much deeper can I go... I'm not sure. I remember reading a measurement for the space between the 1st fret and the string while the 3rd fret is pressed. Anyone care to chime in? I think that string gauge and tuning (1/2 step down, Drop D etc) might also have an effect.

[Mickguard]

As for how much deeper can I go... I'm not sure. I remember reading a measurement for the space between the 1st fret and the string while the 3rd fret is pressed. Anyone care to chime in? I think that string gauge and tuning (1/2 step down, Drop D etc) might also have an effect.

The height is variable -- depends on the guage of string, also depends on the type of finger pressure you use and also personal preference. Some guitarists like a high action there, others like it lower.

I once found a really great chart (might have been on Stew Mac) that showed the exact setup measurements used by the techs for a whole list of famous guitarists. Wish I knew where it was.

And one of the measurements gave the height of the string at the first fret. Believe it was just for the E strings.

The point is, those measurements were pretty exact -- so you might have better luck using a feeler guage to figure out the exact height you're at now -- it'll give you a better idea of where the optimal height should be.