Have you ever tuned your guitar meticulously, only to find that chords and notes further up the neck still sound off? This frustrating issue often points to a problem with your guitar’s intonation. Intonation, in simple terms, is your guitar’s ability to play in tune with itself across the entire fretboard. Setting your guitar’s intonation is a crucial maintenance task that ensures every note you play rings true.
When a guitar is properly intonated, the open strings and each note fretted across the neck will be at their correct pitch. If your guitar sounds out of tune even after careful tuning of the open strings, it’s highly likely that the intonation is off. This can manifest as slight or significant discrepancies in pitch as you move up the fretboard, leading to a noticeably unpleasant playing experience. Even minor intonation problems can be irritating and necessitate adjustment.
Intonation issues are quite common. Guitars are intricate instruments susceptible to environmental changes and general wear and tear, all of which can affect intonation. Temperature and humidity fluctuations, in particular, can significantly impact your guitar’s setup and intonation. Regular intonation adjustments are not just good practice; they are a key component of a proper guitar setup, considered one of the most beneficial maintenance procedures for your instrument.
Fortunately, most guitars are designed with adjustable mechanisms to address these constant shifts in intonation. Intonating a guitar essentially fine-tunes the length of each string, allowing it to play in tune along its entire length. This adjustment is achieved using mechanisms located at the guitar’s bridge. The bridge saddles, where the strings rest, can be moved forward or backward, effectively shortening or lengthening the string’s vibrating portion between the nut and the bridge. These saddles can also be adjusted vertically to control string height, also known as action.
To check your intonation, you’ll need an accurate tuner. Begin by tuning your open string to perfect pitch. Then, carefully fret the same string at the 12th fret and compare its pitch to the 12th-fret harmonic (played by lightly touching the string above the 12th fret and plucking it). If both the fretted note and the harmonic are in tune according to your tuner, then that string’s intonation is correctly set. The string is, in essence, in tune with itself.
However, if you find a tuning difference between the fretted 12th-fret note and the 12th-fret harmonic, the string requires intonation adjustment. The fretted 12th-fret note will either sound sharper or flatter than the 12th-fret harmonic, indicating the direction of adjustment needed.
If your tuner shows the fretted 12th-fret note as sharper than the 12th-fret harmonic, the string is effectively too short. To correct this, you need to lengthen the string slightly. This is done by moving the bridge saddle away from the nut. Adjust the saddle backward until both the fretted 12th fret note and the 12th-fret harmonic are in tune.
Conversely, if the fretted 12th-fret note is flatter than the 12th-fret harmonic, the string is too long. You’ll need to shorten the string slightly by moving the bridge saddle towards the nut. Adjust the saddle forward until both pitches align with your tuner. In some cases, slightly raising the saddle height can also effectively shorten the string length enough to correct flatness.
While electric guitars and basses feature a variety of bridge designs, the vast majority incorporate easily adjustable bridge saddles for intonation purposes. These adjustments are typically made using a small screwdriver or Allen wrench, depending on your guitar’s bridge type.
Step-by-Step Intonation Adjustment
For a basic starting point when setting your intonation, you can use a tape measure. Measure the distance from the inside edge of the nut to the center of the 12th fret. Double this measurement to determine your guitar’s scale length. As a preliminary setup, adjust the bridge saddle for your high E string (first string) so that the distance from the inside of the nut to the center of this saddle matches your calculated scale length.
Next, progressively adjust the saddles of the remaining strings. For each subsequent string, move its saddle back slightly from the previous string’s saddle, using the string’s gauge as a guide for the distance. For instance, if your B string (second string) is .011 inches in diameter, move its saddle back .011 inches from the high E string’s saddle. Repeat this process for the G string (third string), moving its saddle back from the B string’s saddle by the amount of its gauge. The D string (fourth string) saddle is often set parallel to the B string saddle as a starting point. Continue this method for the A (fifth) and low E (sixth) strings, referencing the G string and D string saddle positions respectively.
This initial setup provides a good starting point, but fine-tuning is essential for accurate intonation. After this preliminary adjustment, meticulously check and adjust the intonation of each string individually using the 12th fret harmonic and fretted note method described earlier, ensuring each string is perfectly in tune across the fretboard. Remember to re-tune your open strings after each saddle adjustment and re-check the intonation. This iterative process will help you achieve optimal intonation and a guitar that plays beautifully in tune.
For further exploration into guitar and bass maintenance and playing techniques, Fender Play offers a wealth of lessons to enhance your musical journey.
