Tech Tips: Intonation
Intonation is the ability to keep tune or keep same pitch for the entire length of the fret board. Having good intonation is essential part of playing guitar. You can have a guitar in perfect tune when the string are played open but when fretted they are out or not in sync with the other strings.
The slightest change can cause bad intonation. If you switch string gauges or temperature changes can cause you guitar's neck to shift or change. Also if you adjust the truss rod you may need to change intonation. I have found after I make a truss rod adjustment it is usually the next day before the neck settles then I make intonation settings.
Guitars with individual saddles can be adjusted fairly easy. Your saddles have screws that hold them to the bridge. Tightening or loosening the saddle is how you adjust the intonation of a guitar. This makes the string longer or shorter thus changing intonation. If you look at your saddles they will probably be in different positions, not in a line. A string that has the same pitch played open as fretted on the twelfth fret has good intonation. All strings should have the same pitch played open and fretted on twelfth fret.
Adjusting Intonation of the Guitar
There are a couple things you will need to set your intonation. A screwdriver and good tuner. I recommend a strobe tuner as you will need precise tuning. Also use a chord to connect to your tuner for more accurate reading.
Tune your string played open to pitch. Fret and play the twelfth fret. It should be the same pitch, if it is not here is what you do. If the twelfth fret is sharp move the saddle away from the fingerboard or making the string longer. If the twelfth fret is flat move the saddle closer to the fingerboard or make the string shorter. Remember to keep your hands off the neck after striking the note when tuning. The slightest weight on the neck can change the pitch. Do this for all strings and your guitar's intonation will be complete.