posted 03-31-2003 09:31 AM               

classical players...a question...

I posted my reply supporting nut compensation (which goes against what I have read recently in this forum) and it would be helpful if we could get some professional insights. If my reasoning is full of s**t, I need to know that!

Kevin

posted 03-31-2003 11:48 AM               

Complicating all of this is the issue of how fine do you need to go to make the guitar right and have the owner happy. Some people with perfect pitch won't be happy with equal temperment and search for "sweetened" temperments such as the Feiten method.

posted 03-31-2003 12:06 PM               

quote:

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Originally posted by Randy Reynolds:
Correct me if I'm wrong but the use of a capo would negate any intonation work done at the nut, true?

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Hi Randy: I believe that the effects of nut compensation is not negated by the use of a capo. Here is the reasoning I posted over in Classical Corner:

Regarding nut compensation; it does not only affect the open strings, and in fact it is effective even when a capo is used. In order to understand why this is, you need to realize that adding compensation to the nut alters the scale length of each string. To better visualize this, take 2 identical guitars with 650mm scales. Guitar A is left unmodified. Guitar B has its nut compensated. The result is that the scale of guitar B is no longer 650mm, in fact each string has a slightly different scale length. Now if both guitars are tuned to concert pitch, the tension of the strings on guitar B will be slightly different than those on guitar A. When fretted or capoed, the tensions of the strings on Guitar B will still be different that those on Guitar A. And since the effective lengths of the capoed strings on Guitar A are the same as the capoed strings on Guitar B, the slight variations in string tension between Guitars A and B will result in slight variations in pitch.

I may be way off base, but it seems to make sense to me.

Kevin

posted 03-31-2003 03:02 PM               

And besides, I think a compensated nut looks cool!

Kevin

posted 03-31-2003 05:21 PM               

Regarding the effect of a capo on nut compensation, I am convinced that a capo does not undermine its effects, although there are numerous other factors (as you mentioned) that can screw up the intonation of any well compensated guitar. But just because action, neck relief, string gauge, or doubling fretting can play havoc with intonation, it doesn't mean we should toss the baby out with the bath water.

posted 03-31-2003 06:25 PM               

quote:

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Originally posted by Rick Turner:
And I do not see how any changes you make at the nut can have any effect at all once you put a capo on the at the first or any other fret and then tune normally. It's no different than putting a string hold down behind the nut of a Stratocaster. The capoed fret becomes the new reference for string scale length.

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The capoed fret is indeed the reference for the effective scale length, but the original compensated scale(s) is what determines the string's tension. Here is how I explain it...if I am in error tell me where.

"Regarding nut compensation; it does not only affect the open strings, and in fact it is effective even when a capo is used. In order to understand why this is, you need to realize that adding compensation to the nut alters the scale length of each string. To better visualize this, take 2 identical guitars with 650mm scales. Guitar A is left unmodified. Guitar B has its nut compensated. The result is that the scale of guitar B is no longer 650mm, in fact each string has a slightly different scale length. Now if both guitars are tuned to concert pitch, the tension of the strings on guitar B will be slightly different than those on guitar A. When fretted or capoed, the tensions of the strings on Guitar B will still be different that those on Guitar A. And since the effective lengths of the capoed strings on Guitar A are the same as the capoed strings on Guitar B, the slight variations in string tension between Guitars A and B will result in slight variations in pitch."

Kevin

posted 03-31-2003 10:16 PM               

Regarding nut compensation; it does not only affect the open strings, and in fact it is effective even when a capo is used. In order to understand why this is, you need to realize that adding compensation to the nut alters the scale length of each string.

As is the case with any steelstring guitar with an angled saddle, which is 99-44/100% of them.

To better visualize this, take 2 identical guitars with 650mm scales. Guitar A is left unmodified. Guitar B has its nut compensated.

How about its saddle?

The result is that the scale of guitar B is no longer 650mm, in fact each string has a slightly different scale length.

As is the case with any steelstring guitar with an angled saddle, which is 99-44/100% of them.

Now if both guitars are tuned to concert pitch, the tension of the strings on guitar B will be slightly different than those on guitar A.

Very slightly different.

When fretted or capoed, the tensions of the strings on Guitar B will still be different that those on Guitar A.

And unless adjusted by retuning, they will sound out of tune: sharp. Because the open string with a compensated nut is under slightly higher tension, the capoed note is sharper.

And since the effective lengths of the capoed strings on Guitar A are the same as the capoed strings on Guitar B, the slight variations in string tension between Guitars A and B will result in slight variations in pitch.

And will sound quite out of tune to the discerning ear. Assuming one really believes one can hear 2¢ difference, or less. Try it. I have been around the block with folks over this a number of times now, armed with little scientific devices such as Conn Strobes and better digital tuners, and a regimen of comparing octaves before and after, with and without. The difference in pitch between an open string with a compensated nut and an open string with an uncompensated one is infinitesimal. While the results are undetectable by the human ear, they can be measured with a tuning device, and the results put the lie to what the listener fondly believes is happening. Put a capo on a guitar tuned with a compensated nut, and it will be out of tune. You’d need to adjust every single fret just a little at every position along each string to make the hoped-for microtonal adjustment true all the way up the neck on every string.

The bigger issue by far is what the mind and ear think they want to hear, and how far they’ll go (consciously or more likely not) to hear it. As any singer or violinist will tell you, a G-sharp and an A-flat are *not* the same note. What makes you think you can strong-arm a pitch-generating system as crude as a guitar to accommodate that degree of nuance?

posted 03-31-2003 11:31 PM               

Regarding nut compensation; it does not only affect the open strings, and in fact it is effective even when a capo is used. In order to understand why this is, you need to realize that adding compensation to the nut alters the scale length of each string.

As is the case with any steelstring guitar with an angled saddle, which is 99-44/100% of them. No disagreement here, Paul, except I am basing my limited findings on how it affects nylon string guitars, where the preponderance of saddles are straight.

To better visualize this, take 2 identical guitars with 650mm scales. Guitar A is left unmodified. Guitar B has its nut compensated.

How about its saddle? See above.

The result is that the scale of guitar B is no longer 650mm, in fact each string has a slightly different scale length.

As is the case with any steelstring guitar with an angled saddle, which is 99-44/100% of them. Again, see above.

Now if both guitars are tuned to concert pitch, the tension of the strings on guitar B will be slightly different than those on guitar A.

Very slightly different. Agreed.

When fretted or capoed, the tensions of the strings on Guitar B will still be different that those on Guitar A.

And unless adjusted by retuning, they will sound out of tune: sharp. Because the open string with a compensated nut is under slightly higher tension, the capoed note is sharper. Ah, here is where I disagree, because the nut compensation that is prescribed by Greg Byers results in slightly shorter scales and therefore slightly LOWER tensions. In order to properly compensate at the nut using Byers' calculations, the fingerboard must be shortened 1mm (actually .97mm) at the nut interface. The nut is then compensated to give back some of what was removed. The G string receives the full -.97mm compensation (no relief is given at the nut), other strings receive corespondingly more relief. With a properly compensated nut, the capoed note is actually under slightly lower tension, which serves to flatten the note made sharp by the capo. Pretty cool, huh?

And since the effective lengths of the capoed strings on Guitar A are the same as the capoed strings on Guitar B, the slight variations in string tension between Guitars A and B will result in slight variations in pitch.

And will sound quite out of tune to the discerning ear. Assuming one really believes one can hear 2¢ difference, or less. Try it. I have been around the block with folks over this a number of times now, armed with little scientific devices such as Conn Strobes and better digital tuners, and a regimen of comparing octaves before and after, with and without. The difference in pitch between an open string with a compensated nut and an open string with an uncompensated one is infinitesimal. While the results are undetectable by the human ear, they can be measured with a tuning device, and the results put the lie to what the listener fondly believes is happening. Put a capo on a guitar tuned with a compensated nut, and it will be out of tune. You’d need to adjust every single fret just a little at every position along each string to make the hoped-for microtonal adjustment true all the way up the neck on every string. Paul, I am not sure what you were comparing to, but if the compensation at the nut ADDED to the scale length as you suggested, then you weren't comparing any system of compensation that I am aware of. Granted, I don't have near the experience that you or Rick have, but I didn't devise this system. It is the product of a very experienced classical guitar builder, whom I am guessing would not have taken the time and energy to do the calculations, publish them and utilize them if they were as problematic as you suggest. What I do know from experience is that the two nylon string guitars I built using the Byers' system of nut and saddle compensation can be capoed and remain very well intonated with very little, if any, retuning. When I compare my guitars (with the Byers compensation) to my Paul McGill classical, I find that, although the McGill has dead accurate intonation with open strings, when a capo is placed at the second fret of the McGill, the fretted notes at the 14th fret are very audibly sharper than the 14th fret harmonics, and re-tuning is required. Lest we forget, Byers prescribes saddle and nut compensation as a system, and his saddle requires slanting and ramping inorder to achieve the proper compensation. so I am concluding some of the benefit is from the compensated saddle. But seeing how the saddle compensation will not work without the coresponding compensation at the nut, the effects of both must be considered.

The bigger issue by far is what the mind and ear think they want to hear, and how far they’ll go (consciously or more likely not) to hear it. As any singer or violinist will tell you, a G-sharp and an A-flat are *not* the same note. What makes you think you can strong-arm a pitch-generating system as crude as a guitar to accommodate that degree of nuance? I am not advocating strong arming anything. What I am proposing, (against much resistance, it seems) is that a system of compensation at both the saddle and the nut can be advantageous to nylon string guitars. I have no idea if the same principles can be applied to steel strings. Remember that phrase the hippies used to use, "Question Authority"? That is precisely what I am doing.

Kevin

posted 04-01-2003 12:21 AM               

I know it’s common practice to have a straight saddle, or a minor tweak on the G, with classical guitars, but I have done fuller compensations on them with great success. From my perspective, adjusting intonation at the saddle is far more effective than diddling with the nut.

Ah, here is where I disagree, because the nut compensation that is prescribed by Greg Byers results in slightly shorter scales and therefore slightly LOWER tensions. In order to properly compensate at the nut using Byers’ calculations, the fingerboard must be shortened 1mm (actually .97mm) at the nut interface. The nut is then compensated to give back some of what was removed.

I have heard him talk about this.

The G string receives the full -.97mm compensation (the nut receives no compensation on this string), other strings receive corespondingly less. The capoed note is actually under slightly lower tension, which serves to flatten an otherwise sharpened note. Pretty cool, huh?

OK, I see this too. I have encountered nuts moved forward and also found the results irritatingly out of tune.

I confess I went to a lecture Greg Byers gave and left partway through because I was nodding off. I just don’t buy his results, much less the reasoning behind his cure, no matter how much he talks about it. Much of it struck me as Princess and the Pea.

Paul, I am not sure what you were comparing to, but if the compensation at the nut ADDED to the scale length as you suggested, then you weren’t comparing any system of compensation that I am aware of.

I have seen them compensated both ways, and always it’s a way of dealing with open strings and certain fretted notes in scales that seem to matter, but always the results are selective to certain examples and don’t apply universally over the entire fingerboard. In fact, for every gain at one point, there’s a loss elsewhere.

I didn’t devise this system. It is the product of a very experienced classical guitar builder. . .What I do know from experience is that the two nylon string guitars I built using the Byers’ system of nut and saddle compensation can be capoed and remain very well intonated with very little, if any, retuning.

We judge by results. If you’re happy, far be it from me to tell you you’re wrong.

When I compare my guitars (with the Byers compensation) to my Paul McGill classical, I find that, although the McGill has dead accurate intonation with open strings, when a capo is placed at the second fret of the McGill, the fretted notes at the 14th fret are very audibly sharper than the 14th fret harmonics, and re-tuning is required.

That doesn’t tell me very much because they are guitars by different makers. I know from long experience that fret spacing on different boards can be extremely different and inconsistent. Fret height can be a factor, nut height as well (especially as if affects lower notes) and I also find different nylon strings responding extremely differently on the same guitar. Some play in tune perfectly well, others are excruciatingly out of tune. I find this brand-to-brand disparity much more extreme than anything I find in the realm of steelstrings.

I am not advocating strong arming anything. What I am proposing, (against much resistance, it seems) is that a system of compensation at both the saddle and the nut can be advantageous to nylon string guitars.

I don’t see them as much different; the same rules of physics apply to each, though they’re functioning with different materials at drastically different tensions and mass variables, so understanding the differences requires some time and effort.

I have no idea if the same principles can be applied to steel strings. Remember that phrase the hippies used to use, "Question Authority"?

Was that really from hippies? Given the state of things in the world right now, I think it’s more timely than ever!

That is precisely what I am doing.

It’s certainly a good thing to do, as the realm of lutherie is loaded with unproductive myth. I have been questioning authority for nearly 40 years, and my ongoing inquiry has included both nylon and steel strings, informed by experience in the violin world as well (where, thank God, they don’t have frets!). I haven’t been able to warm up to Greg Byers’s ideas very much, although I certainly find him a very talented, sincere and intelligent person. I have patiently waded through the compensated nut idea with guitarists and banjoists (whose strings are as slack as classical guitarists’ are) and can’t buy the case for a compensated nut, conceptually or practically. But again, the real issue is: if it works to your satisfaction, that’s what counts. And I salute that.

posted 04-01-2003 07:41 AM               

Paul's comment about string type, fret position and nut height are also valid here. If the McGill has action at the nut that is higher than another instrument that is just right then there can be the microtonal effects mentioned. As a practical example try the Byers system with certain Savarez strings and you'll have no end of problems. Greg did agree in his article that certain string brands will work better than others and indeed things can change if you take string off and swap ends.

I realize that a classical is rarely ever played with a capo. So we may be polevaulting over mouse turds here (as my Grandmother used to say). It is true that barre positions may create a similar effect but there is no way that the barre finger applies nearly the same pressure as a capo. The capo itself will apply different pressure behind the fret and pull in more tension especially with high frets.

Another observation regarding intonation in classicals is that it is only a ballpark issue given the player's attack, finger position and any inadvertent string bending during playing. If you do fine intonation you'll find that the luthier himself can become part of the loop and one can make the string intonate exactly depending on the above mentioned player factors. At some point you get to the conclusion that the physics of intonation is a matter of offsetting errors and subjectivity. Not the type of thing that technical luthiers are willing to hear but it is reality.

posted 04-01-2003 10:27 AM               

So, what amount of saddle compensation do I need to counteract the horrendous sonic affects of grain runout?