Intonation Question

[Ronkirn]

OK I see a major issue.. You are dragging strings across a fixed bridge... that's a major issue. I canot imagine why guys that want a trem on something with a Tele like bridge cannot understand that...

If the bridge cannot move as the tremolo is engaged, there will be intonation and tuning issues.

r

 

[Killing Floor]

But if one half of the string has undergone different changes than the other — say because it gets pushed against frets all the time as pointed by Boreas in post #3 — then maybe the two halves of the string won’t act identically even if they are the same length.
Harmonics on an ideal string don’t change: but out here in the real world things can be more complicated.

A string is a member that only acts in tension. The midpoint of that string in tension doesn’t move from the middle.
Harmonics are bound to integer based order.
Harmonics (flageolet in our terms) occur at 1/2, 1/3, 1/4, 1/5, etc.
It is impossible to have 1/2 and not have another half which is what you are suggesting as I read it.

 

[Boreas]

A string is a member that only acts in tension. The midpoint of that string in tension doesn’t move from the middle.
Harmonics are bound to integer based order.
Harmonics (flageolet in our terms) occur at 1/2, 1/3, 1/4, 1/5, etc.
It is impossible to have 1/2 and not have another half which is what you are suggesting as I read it.

What we are saying is that when a string is new, it is pretty close to perfect WRT consistency in diameter and mass. As the dimensions and properties on the surface and internally change from whatever external/internal sources, this consistency diminishes - causing all sorts of spurious tones and overtones which tend to mask or interfere with the harmonics you mention above - causing "dead" strings. Dying strings don't only lose their sparkle, they also lose the ability to stay in tune. Some people use this to gauge when they are about to break a string! The tuning in this case wanders by the minute. Depending on what type of tuner one is using to intonate the instrument, it can be a nearly impossible task. Some tuners simply don't do a great job of filtering out spurious tones from a mishmash of vibrations coming from an old string. Just watch the tuner wander as the string vibrates!

 

[Ronkirn]

It is impossible to have . . .

True.. IF the vibrating item is consistent throughout.. but, contaminate a string with a hunk of glop to a section of it and see what happens...

now the question is, how much smaller must the hunk of glop be before it's mass no longer effects the "consistent' vibrating nodes? The answer is, it cannot be... as long as there's SOMETHING there.. it's going to influence the vibrations... However, it is also true, that the mass or the contamination can be so small as to not influence anything to the point it;'s sonically noticcablle..

However also true, all this mumbo Jumbo can be avoided if ya use new, clean strings..

 

[Boreas]

Here's the guitars in question, and some more info:

On all the electric guitars we use a 1.0 thick/ stiff pick. strings would be 10-48 or 11-52. Our weather in South Africa is much more moderate/ less extremes than other parts of the world, so don't find we need to adjust say neck relieve between seasons.
Setup I would say I pay a great deal of time to setup each guitar. Setup specs would be to Fender specs (string height, relieve, pup height....) intonation is checked every time new strings goes on (open string/ 12th string harmonic/ fretted 12th string).

My Tele with Wilky bridge with B5 trem. Lives in it's case. Both my son and I play this guitar. Not too much string bending, little use of trem, but we play lead and rhythm. Intonation goes off after say 8hrs play and becomes really false after say 16hrs play.

View attachment 1070796

The Bird (my son's guitar): Tele geometry, neck-through construction, Wilky bridge. Lives hanging on the wall and we live by the coast. Both our hands are acidic and the strings do "corrode". Just quaifying - it's not rusty, just not shiny and in pristine condition after time (see below). Not too much string bending, but he plays lead and rhythm. He is lighter on his strings than I i.e. lighter strumming and attack on the strings.
This guitar's intonation goes out the most. It starts happening (noticing it) after about 8 hours of play (can be as little as a week), but then will get to the point of just sounding false higher up the neck (it goes flat), so you can tune it to have either lower frets in tune or high up, but it just sounds silly when playing all over the neck. You can't even use it in a live rock band setup then - this with say 15hrs of play on it.
View attachment 1070794 View attachment 1070795


MIA strat, lives in it's case, lot's of string bending and heavy use of floating trem. When I played alot, it would be say 1-2 hrs a day, but even after 20 hrs of play the intonation is still such that I can use the guitar in a live band setting, but normally would change the thinner strings say once a week. Have never felt I had to change the strings due to the intonation being too far out, but yes fresh strings sound better, but is not always possible for various reasons.
View attachment 1070797

There is off course also my acoustic guitar (Cort, but higher end model), the strings on there is 6 months plus old, prob 100 plus hrs of play, intonation is off past the 11th fret, but I can still use it in a live band setting without it sounding false in the mix past the 11th fret if I had to. (I only play this guitar up to the 11th fret and only rhythm cords), and somehow it still sounds good enough with the old strings on for live playing.

But what I'm hearing from you, is not anything to do with build quality or even hardware choice, it's mainly just string age, but as I said above, there just seems to be a marked difference between the amount of deterioration of intonation from my Fender and acoustic guitar to the others. And I can live with it/ work around it, was just hoping to maybe get to the reason for what we're experiencing.

To the OP, the perfect solution is to change all of your strings more frequently. I would be willing to bet many players change their strings before 10 hours of play. 10 hours is 3-4 gigs?

You could search for a different string that may work better with your physiology and playing style - including treated or coated strings. Another thing I didn't notice (but may have missed) is how you care for your strings. Do you "ride them hard and put 'em up wet", or do you carefully clean and dry the strings/neck? Do you use anything like Fast Fret which helps reduce corrosion and minimizes friction - essentially prolonging the life of the string? I suspect simply drying/cleaning/conditioning after any session will prolong the life of your strings. But strings are like tires on a race car - there is a lot riding on them - so don't spend big bucks on a guitar and skimp on the strings!

 

[Killing Floor]

True.. IF the vibrating item is consistent throughout.. but, contaminate a string with a hunk of glop to a section of it and see what happens...

now the question is, how much smaller must the hunk of glop be before it's mass no longer effects the "consistent' vibrating nodes? The answer is, it cannot be... as long as there's SOMETHING there.. it's going to influence the vibrations... However, it is also true, that the mass or the contamination can be so small as to not influence anything to the point it;'s sonically noticcablle..

However also true, all this mumbo Jumbo can be avoided if ya use new, clean strings..

I don’t leave them on forever.

Not too long ago I found the winding on a D was broken, I assume at a fret. It slid up in a clump. Pretty not-so-subtle reminder to change strings.

 

[old school fender]

Quite the dilemma! I'm not the world's leading authority on this subject but I have enough knowledge to know that in order for intonation to change that quickly one of two things is happening: something is wearing rapidly (strings, nut , frets , bridge saddles or any point of contact between the strings and the guitar) or something is moving, again,anywhere the string contacts the guitar.

You appear to be knowledgeable enough to have an understanding of the premise I have made as to what can possibly be the cause. Edit, in the comment above I left out string trees and tuning pegs and string through body ferrules. Before I go any further I would like to clearly state that anything I have said or will say is not intended to impune the quality of your builds or the extent of your knowledge, just trying to help you find the solution to your issue.

I will assume that you have checked for possible binding and releasing of the string at the nut and at the bridge saddles or string creep at the saddles causing the string to move on the saddle and at a later time go back to there original position (happens all the time on three saddle tele bridges). I will also assume that you have checked all the hardware for any kind of movement (nut loose in the slot, bridge plate not securely fastened, worn tuning pegs that are wobbling around in the ferrule, anything moving that shouldn't be)

At this point, having ruled out any thing sticking, or any of the associated hardware moving I would be back to wear. In my opinion the only thing that could wear that quickly under normal playing conditions is strings, unless of course you playing aggressively enough that your having to do a fret job or replace the nut or saddles every three months.

If you ruled out string wear as the cause, we're back to movement. The only thing left to move is the wood itself. By stating that you don't find it necessary to make seasonal adjustments to neck relief tells me the wood on the neck is relatively stable. The body could be a different story. I would like to think that anyone selling bodies would take the proper steps to assure that the wood was dried in the proper manner and was suitable for it's intended purpose. Also note that different woods can react, sometimes pretty drastically, to the same environment. You could have all your afore mentioned guitars stored in the same place, same temperature and humidity levels, and the difference in the woods, or the finish's, could make a substantial difference. Is this the answer to your question? I surely don't know. Just something to think about.
.

 

[Freeman Keller]

FK, hope I've answered some of your questions in my post above

That does help a lot. I think there are several things going on here and there is a whole lot of people talking - I'm mostly going to beg out of this discussion. I'll make a couple of comments however,

First, "intonation" to me is the adjustment of the string length to compensate for the fact that notes get sharper as strings are fretted. That happens for two reasons - first, the string is stretches as it is pushed down to the fret, no different that when you bend a note forcing it to go sharp. The second reason is that real strings have bending stiffness which also increases the vibrating frequency. Bending stiffness is a function of string parameters, primarily the diameter of the core and is different for each string.

Most of us lay out string spacing using some variation of the "Rule of 18" which results it an equally tempered scale which also causes notes to be out of tune. This is different from the sharpening due to fretting, but we hear it just like we hear the sharpening.

We can somewhat correct the first phenomena by making the vibrating length of the string slightly longer. Its not perfect, but audiologists tell use that most people can't detect less than 5 cents difference between two notes - for many people that is their target. If I know enough about the string I can actually calculate the amount that it must be lengthened to "compensate" for the sharpening, but its hard to get all the string parameters (D'Addario has them on their web site). Most of the time using a good tuner and comparing the fretted 12th fret note with the harmonic is adequate - if the fretted note is sharper than the harmonic then we add a little more length (move the saddle away from the nut). A decent digital tuner will read in cents sharp or flat - I find that adequate.

There is no reason for that to change with string age unless the string itself (or the action setup) changes. You said that it was primarily the E, B, and G strings - I assume those are plain in your sets - those are less likely to change than the wound strings. However the B and G have pretty large diameters compared to the cores of the wound strings, they do take a fair amount of additional length.

If I understand your statement that "it goes flat" I'm assuming that the fretted 12th fret note has gone flat compared to the harmonic. The tells me that it is now over compensated, ie the saddle is too far from the bridge. Strings do stretch with age (and temperature and humidity) but that should be so minor as to not affect the actual intonation.

So I'll say that I don't know what is going on. I'm not an expert on Bigsby's but when I've installed them I've used roller bridges. I've been asked to remove one from a guitar that would not stay in tune. I've also installed locking and roller nuts on guitars with tremolos - but several of your guitars don't have them so I don't know.

I will quickly address your acoustic guitar. Most acoustics are poorly compensated - most have the generic slanted saddle slot with about 1/16 of compensation on the high E and 3/16 on the low. Many will have the B and low E pushed to the back of the saddle, high E and G to the front. It works because most acoustic players never go much above the 7th or 8th fret, the sharpening is neglectable. And as one of my jazz playing friends told me, he can always sharpen a note with his fretting hand as he plays it, but he can't make it flatter. If your Cort really bothers you there are things that can be done for it, but again, I don't think that is part of this discussion.

If you are interesting in a bunch of the theory behind intonation and compensation I can point you to some pretty scholarly works. But I'm afraid I can't answer your initial question.

 

[crazydave911]

I have made many neck-thru guitars and NEVER seen this issue (I live in the Southeast US, mostly warm but humid). The only time I've ever seen anything close was people making guitar bodies from cross grained wood and strings exposed to sea air. I've no clue how those guitars are constructed but I find it revealing the only one not giving you problems was made by Fender who do NOT use cross grained bodies no matter how cheap the variety

 

[Slowtwitch]

To the OP, the perfect solution is to change all of your strings more frequently. I would be willing to bet many players change their strings before 10 hours of play. 10 hours is 3-4 gigs?

You could search for a different string that may work better with your physiology and playing style. Another thing I didn't notice (but may have missed) is how you care for your strings. do you "ride them hard and put 'em up wet", or do you carefully clean and dry the strings/neck? Do you use anything like Fast Fret which helps reduce corrosion and minimizes friction - essentially prolonging the life of the string? I suspect simply drying/cleaning/conditioning after any session will prolong the life of your strings. But strings are like tires on a race car - there is a lot riding on them - so don't spend big bucks on a guitar and skimp on the strings!

Good comments Boreas, I don't take as good care for my strings as I should, but do wipe them down after sessions, but only now and then, should do i every time. On the other hand, my son (The Bird which is the worst affected is his main guitar), never clean his strings (or guitar) - I will address this.

I've never herd of Fast Fret - will investigate thx

 

[Boreas]

Good comments Boreas, I don't take as good care for my strings as I should, but do wipe them down after sessions, but only now and then, should do i every time. On the other hand, my son (The Bird which is the worst affected is his main guitar), never clean his strings (or guitar) - I will address this.

I've never herd of Fast Fret - will investigate thx

Fast Fret is just a light mineral oil on an applicator that you wipe onto your strings after wiping them down. Most people that use it only use it occasionally, but it can be used after every session. If you use it frequently, I would advise against getting much on the fretboard, as any oils can accumulate in the wood.

 

[Slowtwitch]

That does help a lot. I think there are several things going on here and there is a whole lot of people talking - I'm mostly going to beg out of this discussion. I'll make a couple of comments however,

First, "intonation" to me is the adjustment of the string length to compensate for the fact that notes get sharper as strings are fretted. That happens for two reasons - first, the string is stretches as it is pushed down to the fret, no different that when you bend a note forcing it to go sharp. The second reason is that real strings have bending stiffness which also increases the vibrating frequency. Bending stiffness is a function of string parameters, primarily the diameter of the core and is different for each string.

Most of us lay out string spacing using some variation of the "Rule of 18" which results it an equally tempered scale which also causes notes to be out of tune. This is different from the sharpening due to fretting, but we hear it just like we hear the sharpening.

We can somewhat correct the first phenomena by making the vibrating length of the string slightly longer. Its not perfect, but audiologists tell use that most people can't detect less than 5 cents difference between two notes - for many people that is their target. If I know enough about the string I can actually calculate the amount that it must be lengthened to "compensate" for the sharpening, but its hard to get all the string parameters (D'Addario has them on their web site). Most of the time using a good tuner and comparing the fretted 12th fret note with the harmonic is adequate - if the fretted note is sharper than the harmonic then we add a little more length (move the saddle away from the nut). A decent digital tuner will read in cents sharp or flat - I find that adequate.

There is no reason for that to change with string age unless the string itself (or the action setup) changes. You said that it was primarily the E, B, and G strings - I assume those are plain in your sets - those are less likely to change than the wound strings. However the B and G have pretty large diameters compared to the cores of the wound strings, they do take a fair amount of additional length.

If I understand your statement that "it goes flat" I'm assuming that the fretted 12th fret note has gone flat compared to the harmonic. The tells me that it is now over compensated, ie the saddle is too far from the bridge. Strings do stretch with age (and temperature and humidity) but that should be so minor as to not affect the actual intonation.

So I'll say that I don't know what is going on. I'm not an expert on Bigsby's but when I've installed them I've used roller bridges. I've been asked to remove one from a guitar that would not stay in tune. I've also installed locking and roller nuts on guitars with tremolos - but several of your guitars don't have them so I don't know.

I will quickly address your acoustic guitar. Most acoustics are poorly compensated - most have the generic slanted saddle slot with about 1/16 of compensation on the high E and 3/16 on the low. Many will have the B and low E pushed to the back of the saddle, high E and G to the front. It works because most acoustic players never go much above the 7th or 8th fret, the sharpening is neglectable. And as one of my jazz playing friends told me, he can always sharpen a note with his fretting hand as he plays it, but he can't make it flatter. If your Cort really bothers you there are things that can be done for it, but again, I don't think that is part of this discussion.

If you are interesting in a bunch of the theory behind intonation and compensation I can point you to some pretty scholarly works. But I'm afraid I can't answer your initial question.

Thx FK... and in reply to Ronkirn, I did much research in choosing hardware config for that Bigsby tele with the Wilky bridge (fixed saddles) and am happy with it, but knew of the risk going in. For the minimal amount of trem "flex" usage, tuning stability is not an issue (just for the record). And the tele is not the one that deteriorates the most, it's The Bird with fixed Tele string through bridge.

My thoughts on the issue is that I wondered about the fret spacing. I use the "Rule of 18" to space my frets, and position them using CNC to scribe the centers of the fret slots, and I believe my bridge positioning is quite accurate, and with new strings it works well. But somehow I feel like the spacing is not perfect, and when the strings start to age, it shows up with intonation. Whereas Fender might use a hybrid of the "Rule of 18" which is more appropriate/ more forgiving, and hence when strings age, the intonation does not suffer so quickly.

 

[Slowtwitch]

I have made many neck-thru guitars and NEVER seen this issue (I live in the Southeast US, mostly warm but humid). The only time I've ever seen anything close was people making guitar bodies from cross grained wood and strings exposed to sea air. I've no clue how those guitars are constructed but I find it revealing the only one not giving you problems was made by Fender who do NOT use cross grained bodies no matter how cheap the variety

Thx Dave, thinking out the box. I like it, but my guitars are never built cross grain

 

[Slowtwitch]

Quite the dilemma! I'm not the world's leading authority on this subject but I have enough knowledge to know that in order for intonation to change that quickly one of two things is happening: something is wearing rapidly (strings, nut , frets , bridge saddles or any point of contact between the strings and the guitar) or something is moving, again,anywhere the string contacts the guitar.

You appear to be knowledgeable enough to have an understanding of the premise I have made as to what can possibly be the cause. Edit, in the comment above I left out string trees and tuning pegs and string through body ferrules. Before I go any further I would like to clearly state that anything I have said or will say is not intended to impune the quality of your builds or the extent of your knowledge, just trying to help you find the solution to your issue.

I will assume that you have checked for possible binding and releasing of the string at the nut and at the bridge saddles or string creep at the saddles causing the string to move on the saddle and at a later time go back to there original position (happens all the time on three saddle tele bridges). I will also assume that you have checked all the hardware for any kind of movement (nut loose in the slot, bridge plate not securely fastened, worn tuning pegs that are wobbling around in the ferrule, anything moving that shouldn't be)

At this point, having ruled out any thing sticking, or any of the associated hardware moving I would be back to wear. In my opinion the only thing that could wear that quickly under normal playing conditions is strings, unless of course you playing aggressively enough that your having to do a fret job or replace the nut or saddles every three months.

If you ruled out string wear as the cause, we're back to movement. The only thing left to move is the wood itself. By stating that you don't find it necessary to make seasonal adjustments to neck relief tells me the wood on the neck is relatively stable. The body could be a different story. I would like to think that anyone selling bodies would take the proper steps to assure that the wood was dried in the proper manner and was suitable for it's intended purpose. Also note that different woods can react, sometimes pretty drastically, to the same environment. You could have all your afore mentioned guitars stored in the same place, same temperature and humidity levels, and the difference in the woods, or the finish's, could make a substantial difference. Is this the answer to your question? I surely don't know. Just something to think about.
.

Thx for your input, I'll revisit all the contact points.
My main guitar is the strat with a floating trem, and I use the trem all the time, so I make sure all the contact points are smooth/ well lubed on all my guitars.