compensated nuts

[iiipopes]

Just explain to me how a compensated nut can change the distance between any fret and the saddle.

It doesn't. It compensates for the string stretch which is most noticable on the first few frets. This depends on the strings as well as the nut. I have a guitar that when you put flats on it, for example, the third fret G on the low E string is in tune. When you put rounds on it, the G pulls sharp and I have to put a sliver in to compensate.

Think about it: Delft, Earvana, Feiten, Philadelphia Luthier's Supply, EBMM, etc., all are systems of compensated nuts. They aren't just blowing smoke. Surprisingly, so does Gibson, they just never talk about it. The scale on many Gibson guitars that have the nominal 24 3/4 scale length is actually a shade less because the nut is compensated for the first few frets string stretch. I have had several Gibson guitars over the years that have had this.

 

[Turnaround]

It doesn't. It compensates for the string stretch which is most noticable on the first few frets.

Clearly, you can see from my tests, that the stretch even at the first fret with a well adjusted nut has less of an effect than moving the instrument. With a conventional, well adjusted nut, the intonation error is less than one-half of one one-hundredth of a semi-tone. The effect of gravity is well over 10 times that.

 

[iiipopes]

Clearly, you can see from my tests, that the stretch even at the first fret with a well adjusted nut has less of an effect than moving the instrument. With a conventional, well adjusted nut, the intonation error is less than one-half of one one-hundredth of a semi-tone. The effect of gravity is well over 10 times that.

I question your methodology and your measurements. I suggest you also review the work of Dr. Kemp at the University of St. Andrews, Scotland, and his laboratory experiments on the strings themselves and how strings can be sharp. There are a couple of threads on this subject on the forum, including our dialogue in the threads.

The bottom line: some basses need nut compensation. Others don't. Keep an open mind that your measurements aren't the only measurements, and that your conclusions on your limited number of samples is less than statistically significant compared to the numerous companies and manufacturers which find nut compensation integral to their products.

 

[Turnaround]

I am quite aware of the studies that have been done. And the results as they are measured in a laboratory. In practical terms on a bass there are factors that have far more impact than the bit of string-stretch at the first fret. Such factors include variance in the pressure applied to the string by the player in the heat of performance, the amount of accidental "bending" of the string, the amount that the player moves when playing, the freshness, gauge and compliance of the strings, the key the piece of music is in, etc. I admit, if you could take those factors out of the equation there would be a small benefit in the compensated nut.

 

[spatters]

Could it be that laboratory tests don't account for the force with which players actually press on the strings when playing fretted notes, as opposed to the perfectly light touch used when doing lab tests?

It's more difficult to fret at the first two frets, particularly with bass strings, because they're thick and don't like to bend. Fretting gets easier as you go up the neck a few frets, then harder again as the action gets higher. Perhaps that's what a compensated nut helps with?

I know that when playing guitar, the G and B strings tend to go sour on cowboy chords near the nut...and even though a compensated nut should mathematically make the most difference on the lower strings, in reality it seems to make the most difference on the top three. This makes me think that the problem has more to do with how players actually fret the strings...which is different for bass and guitar.

 

[Turnaround]

Could it be that laboratory tests don't account for the force with which players actually press on the strings when playing fretted notes, as opposed to the perfectly light touch used when doing lab tests?

It's more difficult to fret at the first two frets, particularly with bass strings, because they're thick and don't like to bend. Fretting gets easier as you go up the neck a few frets, then harder again as the action gets higher. Perhaps that's what a compensated nut helps with?

I know that when playing guitar, the G and B strings tend to go sour on cowboy chords near the nut...and even though a compensated nut should mathematically make the most difference on the lower strings, in reality it seems to make the most difference on the top three. This makes me think that the problem has more to do with how players actually fret the strings...which is different for bass and guitar.

Chords at the first couple of frets is where you will hear a difference on a guitar. It is exacerbated on guitar because of the shorter scale than on a bass. Not many of us are playing chords at the first fret on our basses. And the longer scale length of the bass will produce less of an intonation error.

 

[Arie X]

as i stated earlier, more of a benefit on an open tuned guitar than a bass imo. otoh, playing open chords on a six string bass would be an interesting tangent regarding the compensated nut debate. fwiw, i guess it depends upon what type of player you are; performance oriented or technically obsessed?

 

[spatters]

Chords at the first couple of frets is where you will hear a difference on a guitar. It is exacerbated on guitar because of the shorter scale than on a bass. Not many of us are playing chords at the first fret on our basses. And the longer scale length of the bass will produce less of an intonation error.

But bass strings are proportionally thicker and heavier, so the same intonation issues arise proportionally for a bass. (This is proved by the fact that bridge saddles on a bass are adjusted to sounding lengths that differ just as much, proportionally, as those on a guitar.) The intonation issues are just less obvious because, as you say, people don't play cowboy chords on a bass.

In fact, in my experience, people use the first three frets on a bass much less than they use them on a guitar in general. This makes the case for compensated nuts weaker on a bass, but it still exists, and I have no doubt that some people, on some basses, find that they make a difference.

Again, I think the issue that compensated nuts fix is that fretting requires varying finger pressure at different locations on the neck, and thus different notes tend to be pulled sharp by different amounts, as opposed to the couple cents of difference that compensated nuts make with perfectly fretted notes.

 

[Turnaround]

But bass strings are proportionally thicker and heavier, so the same intonation issues arise proportionally for a a bass.

What I meant was a 1/16" difference of placement on a bass is less proportionately than it is on a guitar because of the difference of scale.

 

[Jazz Ad]

Just explain to me how a compensated nut can change the distance between any fret and the saddle.

If you want to be absolutely rectal about this, it does. Intonation is usually adjusted against an open string. If the edge of the nut is slightly further, you may adjust the saddles accordingly and doing so, slightly alter the distance between frets and saddles.
Like for the whole thing, I don't think it makes any difference at all on a bass. But yeah.

 

[Arie X]

fwiw, intonation involves getting the mid point of individual compensated string lengths, centered over the 12th fret (the octave).

the nut shelf or slot, and fret spacing is set (one hopes) with good craftsmanship, machine tools, or both and technically you can be .030 off which is way too much imo, but anyway, seems to be the amount that "normal" hearing can detect.

certainly there are tweaks that can be made but imo having a good set up, the right neck relief for the instrument, and the best possible string height at the nut goes a long way towards a better playing guitar or bass.