What is Intonation?
Intonation is the uniform distribution of notes along the fretboard. Each fret corresponds to a note. We set intonation to ensure that each fret's note is as close to in tune as possible. It can be hard to grasp at first, but stick with me here.
How do you adjust intonation?
You adjust intonation by changing the the length of the guitars strings. This is done via a set screw at the end of each string saddle.
The tools you will need:
1. Phillips head screwdriver
2. Flat head screwdriver
3. Very Sensitive Guitar Tuner
The Rules on String Length:
Shorter = Sharper
Longer = Flatter
Steps to Perfect Intonation
The Goal is to match your open string to the 12th fret note of that string.
If you have a 24 fret guitar, you can use the 12th and 24th frets for precise intonation.
Start with your high e string. Play a 12th fret harmonic to ensure its in tune. (I often prefer to use an open string instead of a harmonic.
Now very lightly play the same note, but this time depressing the string at the 12th fret. Compare the difference between the harmonic note and the fretted note.
If the fretted note is sharp, you must lengthen the string. Start with a half turn with your screwdriver.
If the fretted note is flat, you must shorten the string. Start with a half turn with your screwdriver.
Retune the string.
Check your results, and repeat the process until the harmonic and fretted notes are exactly in tune.
Do this for all six strings.
(Pro Tip: A properly intonated guitar will always follow this same pattern. Use this as a guideline to achieve perfect intonation.)
If at any point you aren't confident that you are doing it correctly, just check the pattern. I sometimes do that when adjusting intonation on a Floyd Rose style bridge.
(Pro Tip 2: If your guitar has 24 frets, you can also intonate using the 24th fret harmonic. By using the 12th fret and 24th fret you will achieve an even greater degree of intonation. )
(Pro Tip 3: If you notice your 12th fret notes are "wobbly" or "swaying" on your tuner's display, try a lighter touch when both fretting and picking.)
(Pro Tip 4: If your 12th fret notes are constantly sharp according to your tuner, it may be due to you pressing too hard on the string. You can dramatically change the pitch of your note if you apply too much force.)
The Axe Dr.