Intonation problem

[EVOL!]

At the last band rehearsal I noticed an annoying tuning problem with my SG Classic: not staying in tune, but being in tune up and down the fretboard. So Friday night I got out the strobe tuner and checked all of the strings; made sure the 12th fret harmonic matched the fretted note on the 12th fret. The problem is with my G string. The fretted note is sharp and I ran out of room on the bridge. I cannot move the saddle back any farther to correct this.

 

Anyone run into this? Could it be a badly cut nut? The nut is an old one I had around and I do remember now that when it was on my other SG it had intonation problems with the G string.

[ShredAstaire]

Hey EVOL...i had this problem with my SG as well. I did some research online and found that you can flip the individual "nib" on the saddle to get an extra couple of mm to move...let me see if I can find the YouTube vid i learned from. It worked like a charm for me...

 

Here it is!

 

http://www.youtube.com/watch?v=UNhhho9lSP4

[BigKahune]

.

Another thing to check - the string height of that particular string. Sometimes players check the high and low E strings, but not the middle strings. When you do, sometimes you'll find a particular middle string's height is a bit higher than you'd expect - the nut slot is cut a bit higher than the rest, or the saddle slot is cut a bit higher than the rest, or both. The result is the string is stretched more than the others when fretted - the more it's stretched, the sharper the resulting note. This problem crops up more often than you might think on Gibson guitars - particularly at the nut. They've got quite the rep for poorly cut nuts. <no puns intended> B)

[LarryUK]

Could be duff strings?

[DiamondJig]

Could be duff strings?

 

+1

 

if everything has been good before then that's the first thing I'd do is change it

[EVOL!]

The strings are only a couple weeks old and they are the first set of 11s I put on her. The previous owner had her strung up with 10s, which I broke after a week of playing. They don't call me ham-handed for nothing.

[EVOL!]

Hey EVOL...i had this problem with my SG as well. I did some research online and found that you can flip the individual "nib" on the saddle to get an extra couple of mm to move...let me see if I can find the YouTube vid i learned from. It worked like a charm for me...

 

 

Thanks. I was thinking about this and had some hesitation, but I knew this was my best option until I get a new nut cut.

[BigKahune]

.

10 to 11 is a pretty minor change, but maybe with the change your relief has to tweaked back a bit.

[Searcy]

If the problem is here when you fret notes up and down the neck than it can't be fixed with the nut. As soonas you fret a note the nut is removed from the equasion. Try flipping the saddle.

[tazzboy]

I agree with the dead string issue. What brand are you using?

[EVOL!]

I agree with the dead string issue. What brand are you using?

 

Gibson Vintage Reissue, 11 gauge. It's what I have been using on most of my guitars for over a decade.

 

I am going to flip the saddle and re-intonate.

[rguerra]

Gibson Vintage Reissue, 11 gauge. It's what I have been using on most of my guitars for over a decade.

 

I am going to flip the saddle and re-intonate.

And if new strings still fret sharp even if 12th fret and 12th fret harmonic are in, I put my money on a bad cut nut. I've had the G string fret sharp at the 1st, 2nd, 3rd fret. My guitar tech cut the nut a bit deeper and it is now perfect. (happened on SG, and LP Studio Deluxe.)

[Andy R]

And if new strings still fret sharp even if 12th fret and 12th fret harmonic are in, I put my money on a bad cut nut. I've had the G string fret sharp at the 1st, 2nd, 3rd fret. My guitar tech cut the nut a bit deeper and it is now perfect. (happened on SG, and LP Studio Deluxe.)

 

I'll take your money on that one. As Searcy said the nut is out of the equation once the note is fretted.

[Andy R]

Just my humble opinion but I think people use the term setting harmonics too literally. Using the 12th fret harmonic as your open reference will always throw you off. I always use the open note as the reference note and the fretted 12th fret as the intonation note. Tuning by harmonics is not very good in general and you can be quite off by the time you tune the whole guitar. ( lots of reading out there on the subject) My approach is based on logic that being when I am playing 99.9% of the time I am playing open or fretted notes.

 

Again, just my 2 C's but try it and you might be surprised. There is also a method of using a strobe tuner and fretting certain notes for reference and tweaking the strobe a few cents one way or the other. The premise is that instead of your B string being a large number of cents difference out of tune that you spread the difference out across all the string by just a few cents. Sorry I don't have exact details but if you look around you can find info about it.

 

Also agree if you run out of room flip the saddle around......

 

 

 

Andy

[Thundergod]

.

10 to 11 is a pretty minor change,

 

 

Not if they are an 11 set with a 22 G string... that's a hell of a change if you ask me.

[BigKahune]

I'll take your money on that one. As Searcy said the nut is out of the equation once the note is fretted.

 

The height of the nut slots/saddles/action are always in the equation - the further the string has to travel to the fret, the sharper the note because the string tension increases as the string is pressed down to the fret. Just like the difference between contacting the fret with string versus contacting the fretboard - just that little bit makes the note sharper. The greater (higher) the distance from the bottom of the string to the 12th fret, the more length you need in the saddle adjustment to compensate.

 

 

 

Not if they are an 11 set with a 22 G string... that's a hell of a change if you ask me.

 

As I wrote - maybe with the change the relief has to tweaked back a bit. Yes? No?

[EVOL!]

I should add that it was the same whether I tuned against the open string or the twelfth fret harmonic: the octave (twelfth fretted note) was always sharp.

[EVOL!]

Not if they are an 11 set with a 22 G string... that's a hell of a change if you ask me.

 

Gibson Vintage Reissues are .011, .014, .018, .030w, .042w, & .050w.

[tazzboy]

Just my humble opinion but I think people use the term setting harmonics too literally. Using the 12th fret harmonic as your open reference will always throw you off. I always use the open note as the reference note and the fretted 12th fret as the intonation note. Tuning by harmonics is not very good in general and you can be quite off by the time you tune the whole guitar. ( lots of reading out there on the subject) My approach is based on logic that being when I am playing 99.9% of the time I am playing open or fretted notes.

 

Again, just my 2 C's but try it and you might be surprised. There is also a method of using a strobe tuner and fretting certain notes for reference and tweaking the strobe a few cents one way or the other. The premise is that instead of your B string being a large number of cents difference out of tune that you spread the difference out across all the string by just a few cents. Sorry I don't have exact details but if you look around you can find info about it.

 

Also agree if you run out of room flip the saddle around......

 

 

 

Andy

 

I agree with you there Andy. I don't use Harmonics either. Either the Nut, string saddle slot cut or string itself is bad.

[L5Larry]

Using the 12th fret harmonic as your open reference will always throw you off. I always use the open note as the reference note and the fretted 12th fret as the intonation note.

 

The open note and the 12th fret harmonic are always the exact same note, one octave apart, period. They can not differ, this is scientific and mathematical fact. You can not play a sharp or flat harmonic (relative to the open string). The harmonic is a mathematical derivative of the scale length (as are the harmonics you get at the 5th and 7th frets). All you have to do is get close to the 12th fret and you get the same harmonic.

 

To a strobe tuner or scope, it doesn't matter whether you use the open string or harmonic to check against the fretted 12th, but when checking, or adjusting, by ear, wouldn't it make much more sense to use the harmonic so your reference note and fretted note are in the same octave instead of an octave apart?

 

Tuning by harmonics is not very good in general and you can be quite off by the time you tune the whole guitar.

 

So just exactly how would the margin of error using harmonics be any greater than from tuning the fretted notes across the fifth fret? In both cases this falls into the category of operator error. The margin of error is no different, you're still progressively tuning six strings and trying to end up two octaves above where you started.

 

Back on topic: EVOL!, Flip the saddle (this is why ABR-1 saddles are angled to one side and reversible), check your neck bow, adjust your action and set your intonation. Case closed!

[stein]

Every single post is right, but I think there is more:

 

When you pluck a string, it goes slightly sharp when you first pluck it or pluck it hard. A good tuner will pick this up. Plucking a harmonic is accurate, but not always a true representation of how we pluck when playing.

 

The height of the nut (strings) DOES affect intonation at the frets near the nut MORE than the frets in the middle, because to fret the first fret, more pressure is required because there is less string to stretch. It is also true of how high the action is overall, but the nut height will have very little effect when comparing the 12 fret and open, but if the nut is high, the first fret will be sharp, the second a little less, and less each fret until the twelve fret (if it is adjusted to be perfect at that point).

 

Personally, I think the best way to intonate is to adjust to a best happy medium checking all the fret positions. If it turns out the twelfth fret has to be ever so slightly sharp or flat to make the frets at the 3rd-9th frets closer, it is more in tune. Sometimes, if they are ALL sharp it means the nut is flat and needs to come forward a tad.

 

Also, I think it best to tune having the axe in playing position and plucking the strings close to the way I play them-which is different than flat on a bench delicately plucking like we had to do when we had those old quartz tuners.

[TommyK]

Check the string very closely from nut to bridge. Look for bits of wipe down cloth fuzz, gorilla snot or other foreign substance. Look for irregularities.

 

Even though you have a relatively new set of strings, you could have a bad one.

 

Your cheapest fix is to replace the G string to see if that 'fixes' the problem.

[zigzag]

The open note and the 12th fret harmonic are always the exact same note, one octave apart, period... To a strobe tuner or scope, it doesn't matter whether you use the open string or harmonic to check against the fretted 12th, but when checking, or adjusting, by ear, wouldn't it make much more sense to use the harmonic so your reference note and fretted note are in the same octave instead of an octave apart?

 

Bingo. And if you have any kind of ear at all, you won't need a strobe tuner to hear if the fretted 12th matches the harmonic 12th fret.

[brundaddy]

Gibsons are famous for intonation problems with the g string. Can be fussy.

 

"Flip the saddle (this is why ABR-1 saddles are angled to one side and reversible), check your neck bow, adjust your action and set your intonation. Case closed!"

 

I would agree with Larry on that -- going back to basics usually solves the issue. Don't chop up your nut with a hacksaw just yet.

[Andy R]

The height of the nut slots/saddles/action are always in the equation - the further the string has to travel to the fret, the sharper the note because the string tension increases as the string is pressed down to the fret. Just like the difference between contacting the fret with string versus contacting the fretboard - just that little bit makes the note sharper. The greater (higher) the distance from the bottom of the string to the 12th fret, the more length you need in the saddle adjustment to compensate.

 

As I wrote - maybe with the change the relief has to tweaked back a bit. Yes? No?

 

 

Yes I digress it does concerning the open string and the fretted note and I agree if it were high it would make the string more sharp once it has been fretted as compared to the open reference note... But theoretically if you have enough travel on the bridge it could still be compensated for regardless of string height on the nut.

 

 

 

The open note and the 12th fret harmonic are always the exact same note, one octave apart, period. They can not differ, this is scientific and mathematical fact. You can not play a sharp or flat harmonic (relative to the open string). The harmonic is a mathematical derivative of the scale length (as are the harmonics you get at the 5th and 7th frets). All you have to do is get close to the 12th fret and you get the same harmonic.

 

To a strobe tuner or scope, it doesn't matter whether you use the open string or harmonic to check against the fretted 12th, but when checking, or adjusting, by ear, wouldn't it make much more sense to use the harmonic so your reference note and fretted note are in the same octave instead of an octave apart?

 

So just exactly how would the margin of error using harmonics be any greater than from tuning the fretted notes across the fifth fret? In both cases this falls into the category of operator error. The margin of error is no different, you're still progressively tuning six strings and trying to end up two octaves above where you started.

 

 

It's accumulative error. Like cutting one board to length and then using each cut board as a template for the next cut. You will inevitably end up with different length boards.

 

Since guitars are not fretted perfectly, and pythagorean's harmonic intervals are only precise in certain keys, add in all the other variables using a "Perfect" harmonic will yield variable results. Don't blame me it's pythagorean's fault! Concerning the 12th fret harmonic, I would trust this method more if I were playing a fretless as it does show where the string is equal in perspective to the nut and the bridge. Given frets, string diameters etc... I prefer to utilize open and fretted notes in combination with a strobe and my ears. Again, the end result is that you are compensating the accuracy of the tuning across all the strings such that you spread the accumulative error within a few cents as opposed to accumulating a 10 cent or more difference between a couple strings.

 

I also tune to the open 5ths (and 4th) For some reason I have always just tuned using open strings instead of fretting...I do reference the b string (4th fret G string) and tweak it a bit to be in tune with most all the open chords.... I dunno.... Works for me and I am usually in tune faster than anyone else.

 

Here is an article that explains it fairly well. I have read some more "in depth" studies of this but they make my brain hurt. Do with it what you will....

Tuning With Harmonics - It Doesn't Work.by Larry P. Schrof, Copyright 2003As guitarists, we've all been there. You've just finished one of yoursongs at a gig, and a couple of your strings are noticeably out oftune. You've only got about 10 seconds of dead air before the crowdgets antsy. (Not to mention the drummer will probably start mutteringobscenities normally reserved for practice sessions.)No problem! Just pluck the 5th fret harmonic of your lowest string andthe 7th fret harmonic of the next string. Adjust the second stringuntil its harmonic is in tune with the first, and move on to the nextpair. It's quick and effective, right?WRONG. Tuning the guitar using harmonics is probably one of the mostcommon mistakes guitarists today make. Yes, I know - everybody does it.You've probably been doing it for years, and it seems to work. Why,even books and web list it as one of the common methods of tuninga guitar.In this article, I'll explain why tuning with harmonics is notreliable. You'll need to put on your thinking cap for a bit. I'll tryto keep the math to a minimum. It won't hurt too much, I promise.First, we need to start with some basic facts about string acousticsand the open-string notes. When you play a 5th-fret harmonic, itproduces a frequency four times (exactly two octaves) higher than theopen string note. When you play a 7th-fret harmonic, it produces afrequency exactly three times higher than the open string note. (Eventhough this harmonic SOUNDS like a perfect fifth, it is not, andTHAT makes all the difference. More on this in a minute...)Next, we need a list of the frequencies that a perfectly tuned set ofguitar strings will produce. Assuming equal temperament usingA-440, we get:Open Note Frequency--------------------Low E: 82.41A 110.00D 146.83G 196.00B 246.94E 329.62Using this information, you can now determine the frequencies producedby the 5th and 7th-fret harmonics on every string. For example, sincethe A string rings open at 110 Hz, its 7th-fret harmonic will be at330 Hz, and its 5th-fret harmonic will be at 440 Hz.OK. Now that the groundwork is laid, let's see why tuning withharmonics doesn't work. We'll walk through an example. Assume thatyour low E and A strings are in perfect tune, but you want todouble-check them. According to the chart above, your low E string willproduce a tone at 82.41 Hz. Using the method you all know and love,you'll pluck its 5th-fret harmonic. This gives an E two octaveshigher, at 329.64 Hz. Then, you pluck the 7th-fret A-string harmonicand get a 330 Hz tone!Ah hah... do you see the problem? The 330 Hz harmonic of the*PERFECTLY TUNED* A string will sound sharp to you, and you'll detuneit to match the E-string harmonic. What you're actually doing,though, is tuning the A string flatter than it should be by about 0.12Hz! Doesn't sound like much, does it? Well, the A string is now almosttwo cents flat. That's not good news, and the problem gets worse.You are now going to be tuning the next string off of a string that'salready flat. Let's see what happens. Our now-flat A string is ringingopen at 109.88 Hz. You pluck the A-string 5th fret harmonic, thenadjust the D-string 7th fret harmonic to match. When the harmonicsalign, the D string will now ring open at 146.51 Hz. Take a look atthe chart above. We're 0.32 Hz too low. The D string is now almostFOUR cents flat. Notice how the error becomes larger.Continuing in this manner, the G string will end up almost 6 centsflat. Now THAT'S a noticeable difference. Some people like to matchthe D-string's 9th fret harmonic to the B-string's 5th fret harmonic,but that won't work either.In general, tuning strings to any harmonics besides octaves of theopen string notes will yield flawed results. Of course, this all begsthe question - how should one tune? Ideally, you should use anelectric tuner on each string. If using a tuner is not an option, tuneyour high E string to a known correct pitch such as another(already-tuned) instrument. Play the 5th fret of your B and match itup to the high E. Proceed the same way down all the strings, tuningyour low E string last.If you're like me, you found all of this a bit surprising at first,but hopefully a little enlightening. (I personally had been usingharmonics to tune for years.) Needless to say, playing an out-of-tuneguitar not only sounds harsh, it sounds unprofessional and amateurish.So let's get the credit we deserve as players and stop using harmonicsto tune!Practice hard,- Larold