Adjusting Electric Guitar Saddles
How are the Action Adjustments at the Saddle Determined?
Lots of folks simply adjust the saddles by feel. Although this can work, it is not consistent from set up to set up. Instead, it pays off to follow a methodology for adjusting saddles. Not only does this make saddle adjustments quicker, it also makes the process much more consistent from set-up to set-up.
In order to create an even feel without the strings buzzing on the frets, the first string is typically the closest to the frets and the sixth string is furthest from the frets. The strings in the middle should get progressively further from the frets as the saddles are adjusted from the 1st to the 6th string. In order to assert some control over the process, it is wise to use a ruler to measure the distance of the strings from the frets (also called action). Because the 12th fret is the center of the string length it is common to measure the action with a ruler resting on the top of the 12th fret and measuring to the bottom of the strings.
When action is adjusted, it should be done in such a way that fret buzz is avoided. No matter how high or low the action, the strings will buzz on the frets if the strings are struck with enough force by a pick or the right hand fingers. With this in mind, the idea of setting the action “as low as possible without buzzing” is rather subjective. The lower the action, the more the strings will likely buzz against the frets. Therefore, the lower the action, the less dynamic range an instrument has.
Popular Methods for Saddle Adjustment
One popular way of adjusting saddles is to do so by setting the e strings to a given height from the 12th fret, then matching the tops of the a,d,g and b strings by the bridge to a radius gauge. This makes the strings feel even as your hand(s) and pick move across the top of the strings. This method doesn’t provide the most even feel regarding the resistance your fretting hand feels when it depresses the strings against the frets.
Another common way of adjusting the saddles is to set the e strings then match the bottoms (fretboard side) of the inside strings to an under-string radius gauge. Although this makes the resistance your fretting hand feels fairly even, it makes the feel of the strings seem unbalanced as your hand and pick move across the strings.
One draw back to both of these methods is that the frets and fretboard are rarely an exact match to a radius gauge. This allows for the chance of adding to an unevenness of feel.
The Method Used at Finger Lakes Guitar Repair
The idea behind my method of saddle adjustment is to make the action feel more even because you’re making a compromise between the distance your left hand feels from the top of one string to another and the resistance your hand feels when pressing down on the strings. This method also compensates for small variations in the radius of the frets or fretboard. Because of the general increase of tension with string diameter I keep the measurements to the tops of the e strings within each category (x-low action, low action, medium action, etc…) the same whether I’m using 9’s, 10’s, 11’s, etc… Since each string is measured from the top of the 12th fret, the radius of the fretboard is inconsequential.
How to Derive Adjusting Measurements
You must first find the “center line”, an imaginary line that goes through the center of each string as they get progressively higher off the fretboard from the 1st string to the 6th string. Finding the center line begins with determining the center of the e strings. I’ll use “extra low” action with 10’s as an example. Subtract the measurement from the top of the strings (1mm and 2.75mm) by half the diameter of the given string: 1st: .875, 6th: 2.165
Now that you have the lowest and highest points of the center line you must determine the interval by which each string measurement is increased from the previous. 2.165mm – .875mm = 1.29mm divided by 5 (the number of steps up from the 1st string to 6th string) = .258mm This is the interval by which each string center will increase above the previous.
Now add .258mm to .875mm (the center of the high e string) to get the center of the 2nd string = 1.133. Continue adding .258mm to the previous string measurement until you have the centerline measurement for each string:
The last step is to find the measurement to the top of each string that you’ll be making. Add half the diameter of each string to it’s center line measurement: .875mm + .125mm= 1mm (final adjustment measurement to the top of the 1st string).
These are the final adjustment measurements (measured from the top of the 12th fret to the top of the strings) for each string given that 10’s and “extra low” action are desired.
To make things a little more accurate/consistent, I place the ruler against the side of the string opposite to my eyes and tilt the upper bout of the guitar away from my body until I can just barely see the point of contact between the top of the 12th fret and the bottom of the ruler.
An electric guitar with individually adjustable saddles such as a stratocaster is pretty easy to set the action at the saddles. However, arch-top guitars and guitars with tunomatic style bridges require the aid of nut slotting files if truly dialing in the saddles is desirable.
Saddle adjustment is only one aspect of setting up a guitar. For more information about set-ups please visit our set-up repair descriptions page for detailed photo-documented set-ups.