Nylon string intonation

[achase4u]

So I have been wanting to record a new tune, and unfortunately I only have two very cheap nylon guitars. I figure the frets are cut out of place or something.

Anyway - on some strings the notes can be flat at the 5th fret and sharp at the 7th. This happens in different places on the neck on different strings.

I also have this issue on the A string of my Eastman OM. I really am not sure why. I've changed strings allot. I am carefully fretting to check this with a tuner. It makes rhythm guitar just too much to bear. Even if stop on a chord and make sure I am not pulling strings around, it's that way. Made a new nut for one of the nylon guitars and it didn't help. New strings helped a couple unwound strings, but not the wounds.

I tried searching for threads but usually intonation threads are about 12th fret sharpness etc...

Happy Thanksgiving, everyone!

[fitness1]

Originally Posted by achase4u

So I have been wanting to record a new tune, and unfortunately I only have two very cheap nylon guitars. I figure the frets are cut out of place or something.

Anyway - on some strings the notes can be flat at the 5th fret and sharp at the 7th. This happens in different places on the neck on different strings.

I also have this issue on the A string of my Eastman OM. I really am not sure why. I've changed strings allot. I am carefully fretting to check this with a tuner. It makes rhythm guitar just too much to bear. Even if stop on a chord and make sure I am not pulling strings around, it's that way. Made a new nut for one of the nylon guitars and it didn't help. New strings helped a couple unwound strings, but not the wounds.

I tried searching for threads but usually intonation threads are about 12th fret sharpness etc...

Happy Thanksgiving, everyone!

I'd recommend going to Frets.com and reading up on how to intonate a saddle.....I use a simple, half round needle file to intonate each string.

Potential problem is that most classicals don't have a very thick saddle, so there's not that much room for adjustment.

[GHS]

The above post has good advice. What I can add is this. In the time I had been searching for a nylon string in my price range, (500-750) I have found intonation problems with anything around the 200-300 dollar range. You state in your opening line you have two CHEAP nylons. That in itself may be the whole problem. My instructor, who has a lifetime of experience has confirmed my findings. There are exceptions, I'm sure, but I have not found them.

[WaddyT]

Even expensive production nylon string guitars will often have some intonation issues. They are all built to a standard. Few even have saddle intonation.

[achase4u]

It's true that all fretted instruments will suffer intonation issues. Especially if you think about flying around chord changes up the neck in jazz on a nylon. Luckily they don't sustain long enough to hear some of the issues.

I would just like an improvement. My Eastman OM was 700 dollars, and for some reason I can't find a set of 12's that will intonate well - usually one or two strings won't behave. Strange. It's mostly a problem with jazz chords up the neck.

I appreciate the advice, everyone. Still beats trying to stay in tune on a trumpet.

[fitness1]

Originally Posted by achase4u

My Eastman OM was 700 dollars, and for some reason I can't find a set of 12's that will intonate well - usually one or two strings won't behave.

As noted above, it's actually very common. I've owned very expensive instruments that didn't intonate correctly "out of the shop".

Learn how to check intonation and remedy the problem. It's not likely the strings!

[FrankB2]

I had a Giambattista classical (around $2,000), and they're made to be used with Savarez Corun Alliance strings. I pulled off the stock strings, and the nylon EJ45 G string was flat. I tried another, and it was still flat. I tried another brand, and it was still flat. I made a compensated saddle, and it was fine. A week later, I switched back to Corum Alliance.

The two classicals I recall having wider than usual saddles, were a LoPrinzi and a LaPatrie. The rest are pretty thin.

[Dafiryde]

Greg Voros once told me that acoustic guitars have a fixed intonation, and 99% of the times it will be out by just a few cents, something that the average ear wont even reconise.

[815C]

I have a factory 2nd Alvarez that has intonation problems. If its in tune at the 1st position, its out of tune at the 7th position, and vice versa.

However, I have found that putting a new set of strings on the guitar will help significantly - for awhile.

Remember that the pitch of a string is dependent upon 3 things:

• The length of the string
• The tension of the string
• The diameter of the string

As nylon strings age, they stretch. As they stretch, they don't always stretch in a way that the diameter of the string stays uniform along the entire length of the string. For instance, the string may stretch in such a way that the area of the string around the 5th - 7th frets gets a bit thinner than the rest of the string over the other frets of the fret board. This thin section of the string will not intonate correctly because the diameter of the string has been reduced relative to the diameter of the rest of the string.

When putting new strings on a classical guitar, they stretch like crazy when first installed. When putting on new strings, try pinching the string between thumb and index finger and pulling/stretching it at every inch between the saddle and the nut. Do this repeatedly until the string has finished its initial new string stretch period.

Also, use this method to tune your classical vs. using a tuner. It will really help with intonation (I've cut and pasted this from http://classicalguitarbuilder.com/ma...ewsletter.html)

A Simple Method For Accurate Guitar Tuning

I have a great electronic tuner. Ed, one of my classical guitar students, gave it to me as a gift because I was always grabbing his tuner at lessons and playing around with it. Thanks Ed.

Unfortunately for me the tuner isn’t idiot proof and you need to remember to turn it off. I find this difficult and therefore the battery is always dead. To make matters worse I never remember to get a new battery when I’m at the store. Fortunately I have another accurate way to tune my guitar and I haven’t forgotten it yet. Here it is.

Tune the 5th string A. I use an A=440 tuning fork. Play a harmonic by lightly touching the A string above the fifth fret and plucking the string by the bridge. Plucking nearer the bridge will give a clearer harmonic. Adjust the string to match the tuning fork.

All the other strings are now tuned to the 5th string. This is an excellent system because minor pitch errors are not compounded between strings.

E (6th string) -- harmonic 7th fret 5th string = harmonic 5th fret 6th string

D (4th string) -- harmonic 5th fret 5th string = harmonic 7th fret 4th string

G (3rd string) -- play an A on 2nd fret 3rd string = harmonic 12th fret 5th string

B (2nd string) -- play an E on 5th fret 2nd string = harmonic 7th fret 5th string

E (1st string) -- play E first string open = harmonic 7th fret 5th string

Now that the guitar is in tune you can make minor adjustments by comparing unisons (same note different strings) and octaves between various strings.

[charles Tauber]

Originally Posted by 815C

Also, use this method to tune your classical vs. using a tuner. It will really help with intonation (I've cut and pasted this from http://classicalguitarbuilder.com/ma...ewsletter.html)

There are many recommended ways to tune a guitar. This is not one of them.

In short, here is why. Harmonics belong to Pythagorean tuning - whole-number divisions of the string; fretted notes are designed to be equal temperament - each semitone is related to the twelfth root of two, not a whole number. The only places where the pitches (frequencies/string lengths) of these tunings are the same is at octaves and unisons: every other note is different in pitch.

If you are tuning to harmonics that are not an octave (or multiple of an octave) you are mixing apples and oranges and you'll be chasing your tail. That is, you'll get the non-octave harmonics in tune with each other, but when you fret notes they will be out of tune. That's the physics of it. Tune anyway you like that does not involve tuning to non-octave harmonics.

Now that the guitar is in tune you can make minor adjustments by comparing unisons (same note different strings) and octaves between various strings.

Which you know will be necessary based on the method just used to tune them.

Also, tuning to octaves and unisons is fine unless you play other intervals. Thirds are usually those that need the most "tweaking", due to the discrepancy between equal temperament and the Pythagorean (or Just) that the ear wants to hear.

It is important to distinguish between intonation - the ability of an instrument to achieve the desired pitches - and temperament - the target pitches. The guitar is designed to produce notes that conform to equal temperament. If the intonation is "perfect", the guitar achieves those pitches. However, the ear doesn't hear those pitches as being "in tune".

The starting point is to ensure that the guitar accurately achieves the pitches it was intended to produce - those of equal temperament. If not, that is an issue with the setup of that particular instrument, with its intonation. Once that is achieved, one can begin to address the differences between temperaments. If the pitches that the guitar produce are all over the map, so to speak - lacking consistency in their accuracy from fret to fret - there is little hope of addressing the differences between temperaments and the instrument will never sound in tune.

[achase4u]

Well, the intonation at the 12th fret is fine. That's why this issue is more complicated - i e what 815c mentioned.

If my intonation is right at the 12th, and flat at the 5th 10 cents and sharp at the 7th 10 cents... there isn't a saddle in the world that will fix that. It sounds like a string issue - or possibly the frets cut so bad that they are off there? But then why on one string? I've checked the nut, and made another one.

All very puzzling...

[charles Tauber]

Originally Posted by achase4u

If my intonation is right at the 12th, and flat at the 5th 10 cents and sharp at the 7th 10 cents... there isn't a saddle in the world that will fix that. It sounds like a string issue - or possibly the frets cut so bad that they are off there? But then why on one string? I've checked the nut, and made another one.

I'd start with new strings. In this situation, I suggest D'Addario Pro Arte, if only for the reason that I've never had a set that deviated much from playing "true". Some brands are notorious for playing "false".

If that doesn't appreciably fix the issue, I'd measure the locations of the frets. There are on-line calculators that will give the locations for your scale length. Measuring them in mm will make life easier.

10 cents flat and 10 cents sharp two frets away is pretty far off. I'd also measure how many cents off neighbouring frets are, such as fret 4, 6, 8. I'd also measure the first 5 frets while I was at it. That gives a picture of what is happening.

[achase4u]

Funny - I just put on some Pro Arte last night. The intonation improved on several strings - the A is still pretty bad though for some reason.

I will check the frets. I do have some Mitutoyos.

I have a second set of pro arte that I am planning on putting on the other classical. I will see how it improves that one as well...

[charles Tauber]

Originally Posted by achase4u

the A is still pretty bad though for some reason.

Be specific: measure the number of cents out at frets 1 through 12. That will show trends and deviations from the trend. The trend is what nut and/or saddle compensation addresses.

I will check the frets.

It's possible, but frets are very rarely out enough to be the source of intonation problems.

[achase4u]

Ok so - A string

1st - 2.2 cents sharp
2nd - 1.1 cents flat
3rd - 5 cents flat
4th - 8 cents flat
5th - 9 cents flat
6th - 11 cents flat
7th - 9 cents flat
8th - 12 cents flat
9th - 13 cents flat
10th -16.7 cents flat
11th - 4 cents sharp
12th - 5 cents sharp

The Low E is quite flat from 1st to 5th - then 5th up is great.

So all the strings at the 12th are good.

Guess my other tuner is part of my problem. I pulled out my peterson strobe app and things were much more accurate. The strings are definitely flat until the 5th fret or so.

So here is some other pertinent info -

Im having issues on both guitar but lets just focus on this smaller one.

Its an old gremlin, 12 frets to the body - quite small.

The action was really high - so I lowered the saddle a couple days ago - I am now at 5/32" at the 12th fret. I figure the short scale needs a little higher action?

The nut action is only about 1/32"

Maybe the nut is too low and the saddle too high?