Compensated nut
Why a compensated nut?
Often in stringed instruments, the notes of the first frets are slightly sharp and can cause annoying dissonances and beats, especially when playing chords.
If you don’t believe it, try to measure the notes yourself with a tuner: even if the open string is perfectly in tune, it is likely that when pressed on the first frets, it is slightly (or sometimes very) out of tune. This effect is notable also on those instrument where the “regular” compensation (that performed on the bridge, allowing the string fretted at 12th fret to sound perfectly in tune) is working perfectly.
This annoying fact is a consequence of string physics and is typical of both instruments with a standard nut and those with “zero fret”.
The only way to avoid it is to use a compensated nut that has a shape designed to minimize intonation errors. Toghether with bridge compensation, it allows to achieve a perfect intonation over the whole fretboard.
A compensated nut on my F-Jazz mandolin.
Unlike standard nuts, on a compensated nut, each string (or each pair of strings in the case of mandolins) has a slightly different “starting point”.
In the following figures, you can see the difference between a standard nut, a “zero fret” and a compensated nut on a mandolin.
In the graphs, each dot represents the intonation error expressed in cents of the four strings (each one identified by a different color) for each fret. you can read the fret number on the x axis.
Standard nut
Zero fret
A zero fret allows for zero clearance above the other frets and slightly enhances the intonation with respect to a standard nut. Hovever, the overall intonation errors are close to those of a regular, well executed, standard nut.
Compensated nut
Frequently Asked Questions about Compensated Nuts
If I fret the strings, does the compensated nut still affect intonation?
Yes, a compensated nut influences both open and fretted notes. Since the strings start from a slightly different position compared to a standard nut (shifted slightly toward the bridge), it’s as if all the frets are moved slightly towards the nut. This adjustment affects the intonation across the entire fretboard, not just the open strings.
If I change string types, will the compensated nut still work?
Yes. Although a compensated nut is designed for a specific set of strings, it continues to offer improved intonation compared to a standard nut or zero fret, even when different strings are used. While the compensation might not be perfect for all string types, it typically provides better tuning consistency in any case with respect to a standard nut or zero-fret configuration.
What happens if I use a capo?
Using a capo doesn’t negate the benefits of a compensated nut. In fact, it can help reduce intonation errors even when a capo is applied. The compensated nut adjusts the string’s starting point, which continues to influence tuning accuracy, ensuring that fretted notes remain more in tune compared to using a standard nut.