We'll next look at the actual pieces of the apparatus and how they're put together. Moving the bridge too far from the neck increases scale length and creates flat fretted notes. While this calculation is not needed for electric guitars (saddles are quick and easy to adjust) it is very helpful in preparation for making a new saddle for an acoustic guitar, after measuring the pitch errors with the old saddle. 3) You know how to adjust bridge saddle position(s) for best octave fret intonation. Because compensation at the saddle is more common than compensation at the nut, the best way to find the scale length on an existing instrument is to measure from the nut to the twelfth fret and multiply by two, making sure to measure along the center of the fingerboard (most fingerboards are tapered, so it is best to measure between the 3rd and 4th strings on a 6 string guitar). The distance between the guitar nut and bridge is the scale length. How to Calculate Frets on a CBG. Your guitar’s bridge saddle is the most significant piece of the puzzle when it comes to raising or lowering action (the distance between your strings and the fingerboard). Sure, nut compensation goes back a while, but the techniques used are often fairly primitive or fall into the “one size fits all” category. Actually the entire saddle is "compensated" in that it is offset away from the point which which would be determined by the scale length (2 times the distance from the nut to the 12th fret). Figure 1 gives an overview of the jig. In the most ideal bridge, I think the saddle should protrude (as it does above) about 3/16" above the wood. That is also why it is slanted. This makes them sound more musical with more clarity as a consequence of congruent harmonics across strings. The Compensated Nut: an illustrated article on fine-tuning guitars by compensating the nut, written by Stephen Delft. ... You have adjusted the curve and height of the bridge saddle(s) for your preferred action, using fresh strings of your usual kind and gauge, etc. Now we have newly calculated fret positions, \(X''_n\) that follow our canonical formula (Equation 10); we have saddle setback, \(\Delta S\); and we have found a new nut position, \(\Delta N\). Learn More → Correct bridge placement determines a guitar's intonation when playing fretted notes. Nut and saddle compensation make my guitars play much more in tune to the equally tempered scale than most other guitars. We end up with a set of fret positions that, as it turns out, are very close to the theoretical values from our model for string stretch, \(X'_n\). As Chicago says, the B string. If you have a vintage-style through-cut saddle, changing the height is best left to a pro. Most modern guitars have a drop-in saddle that can be removed when the strings are off. In order to test what degree of compensation is needed for the Savarez Alliance classical guitar strings that I use on my ukuleles, I created a simple device in a morning, built mostly from scraps lying about the shop. We can use this equation to calculate the length of compensation needed, or for +or- correction of a previous adjustment. However, the B string requires more compensation than the E or G, so it has a little notch that moves the break point even farther. The saddle may sit "captive" in a groove as it does in the bridge above, or it may be inlaid in a channel cut all the way through at the ends, as in this Martin guitar from the 1950s: Either way, the saddle works the same. Placing the bridge too close to the neck shortens scale length and makes fretted notes sharp.