Getting the perfect sound from your acoustic guitar involves more than just tuning it before each session. Intonation, the alignment of your guitar’s notes across the fretboard, is crucial for ensuring that every chord and note rings true. Whether you’re a seasoned player or a beginner looking to improve your instrument’s performance, understanding and adjusting intonation is a key skill. In this guide, we’ll guide you through the process of checking and correcting the intonation of your acoustic guitar, from the tools you’ll need to common mistakes to avoid.
What is Guitar Intonation and Why Does It Matter?
Understanding Guitar Intonation
Guitar intonation refers to the accuracy of the pitch produced by your guitar as you play up and down the fretboard. When a guitar is properly intonated, each note played on the instrument will be in tune, regardless of its position on the neck. Intonation issues arise when notes are in tune in one part of the fretboard but out of tune in another. This can make playing sound dissonant and unpleasant, even if individual strings are tuned correctly.
The Mechanics Behind Intonation
The primary factor that affects intonation is the length of each string, from the nut to the saddle. As you press down on different frets, the vibrating length of the string changes, which should produce accurate pitches according to the equal temperament tuning system used in modern Western music. However, various factors such as string height (action), string gauge, and even the wear and tear of the guitar can affect intonation. When these factors are not properly balanced, the string length becomes inconsistent, leading to intonation problems.
Why Intonation Matters
Accurate intonation is crucial for several reasons. Firstly, it ensures that chords sound harmonious and pleasing. If your guitar’s intonation is off, chords may sound out of tune even when your open strings are perfectly tuned. This can be frustrating for both beginners and experienced players, as it hampers the overall musical experience. Secondly, proper intonation is essential for playing along with other instruments. In a band setting or during recordings, poor intonation can stand out and negatively impact the overall sound. Finally, for those who play higher up the neck, accurate intonation ensures that solos and melodies are in tune, allowing for expressive and precise performances.
Identifying Intonation Issues
To determine if your guitar has intonation problems, you can perform a simple test. Play a harmonic at the 12th fret of each string and then compare it to the fretted note at the same position. The two should be identical or very close in pitch. If the fretted note is sharp or flat compared to the harmonic, your guitar’s intonation needs adjustment. Regularly checking intonation, especially after changing strings or making other adjustments to your guitar, helps maintain its playability and sound quality.
How Can You Tell if Your Guitar’s Intonation is Off?
The Harmonic and Fretted Note Test
One of the most straightforward methods to check if your guitar’s intonation is off is by using the harmonic and fretted note test. Start by playing a harmonic at the 12th fret of each string. A harmonic is produced by lightly touching the string directly above the fret and plucking it. The resulting note should be a clear, ringing sound. Immediately after playing the harmonic, press down on the 12th fret and play the fretted note. The pitch of the fretted note should match the harmonic. If the fretted note is sharp (higher in pitch) or flat (lower in pitch) compared to the harmonic, it indicates an intonation issue that needs correction.
Comparing Open and Fretted Notes
Another method to check intonation involves comparing the pitch of open strings to their corresponding fretted notes at the 12th fret. Start by tuning your guitar accurately using a reliable tuner. Play the open string and then the note at the 12th fret of the same string. Both should be in tune with each other. If the 12th fret note is sharp, it means the string is too short and needs to be lengthened by adjusting the saddle position. Conversely, if the 12th fret note is flat, the string is too long and needs to be shortened. This method provides a clear indication of whether your guitar’s intonation is correct or requires adjustment.
Using an Electronic Tuner
For a more precise measurement, you can use an electronic tuner. Play the open string and note its tuning on the tuner. Then, play the 12th fret note and check its pitch on the tuner. If the tuner shows that the fretted note is not in perfect tune with the open string, you have an intonation problem. This method allows for more accurate detection of pitch discrepancies and can help you fine-tune your intonation adjustments more effectively. Many modern tuners also offer specific modes for checking intonation, making this process even easier.
Listening for Inconsistencies While Playing
Sometimes, intonation issues can be identified simply by listening carefully as you play. If your guitar sounds in tune when playing open chords but becomes dissonant as you play higher up the neck, this is a strong indication that your intonation is off. Pay attention to whether certain chords or notes sound out of tune, especially when playing with other musicians or along with recordings. This auditory feedback can be a valuable tool in identifying and addressing intonation problems.
Regular Maintenance and Monitoring
Regularly monitoring your guitar’s intonation is essential for maintaining its playability and sound quality. Intonation can drift over time due to changes in temperature, humidity, string wear, and other factors. Make it a habit to check your intonation whenever you change strings, adjust the action, or notice any changes in your guitar’s sound. Keeping your guitar properly intonated ensures that it stays in tune across the entire fretboard, providing a more enjoyable playing experience.
What Tools Do You Need to Adjust Guitar Intonation?
Electronic Tuner
An electronic tuner is an essential tool for adjusting guitar intonation. It provides precise readings of the pitch of each note, allowing you to make accurate adjustments. There are various types of electronic tuners available, including clip-on tuners, pedal tuners, and smartphone apps. Clip-on tuners are particularly convenient because they attach directly to the guitar’s headstock and measure vibrations, making them highly accurate even in noisy environments. When adjusting intonation, the tuner will help you determine if the notes at different frets are sharp, flat, or in tune, guiding your adjustments.
Screwdriver
A screwdriver is necessary for adjusting the position of the saddle on your guitar. Most acoustic guitars have a fixed bridge, but the saddle can often be adjusted to correct intonation. Depending on your guitar’s design, you might need a Phillips head or flathead screwdriver. Carefully consult your guitar’s manual or manufacturer’s guidelines to determine the correct type and size of screwdriver. Using the wrong tool can damage the screws or the guitar itself. The screwdriver is used to move the saddle forwards or backwards to lengthen or shorten the string, thus adjusting the intonation.
Guitar String Winder
A guitar string winder is a handy tool for loosening and tightening strings quickly. When adjusting intonation, you may need to detune and retune the strings multiple times. A string winder speeds up this process, making it easier and less time-consuming. It also helps prevent wear on your tuning pegs, which can be an issue if you frequently make adjustments. Some string winders come with additional features like bridge pin pullers, which can be useful if you need to remove and reinsert bridge pins during the adjustment process.
Capo
A capo is useful for holding strings in place while you adjust the saddle. By placing a capo at the first fret, you can maintain consistent tension on the strings, which helps ensure accurate adjustments. This is particularly helpful when you need to make fine adjustments and want to avoid the string tension fluctuating too much. Using a capo also allows you to keep both hands free for making precise adjustments and checking the tuning.
Feeler Gauges (Optional)
Feeler gauges can be used to measure the action of your guitar, which is the height of the strings above the fretboard. While not strictly necessary for adjusting intonation, understanding the action can help you diagnose and correct intonation issues more effectively. High action can cause intonation problems, as pressing the strings down too far can stretch them and alter the pitch. Feeler gauges help you measure and adjust the action to ensure it is within the optimal range for your guitar.
Pencil or Lubricant
Using a pencil or a specialized guitar lubricant can help reduce friction at the nut and saddle. This is important because friction can cause the strings to bind, affecting tuning stability and intonation. Rubbing a pencil lead (graphite) in the nut slots provides a simple, effective lubricant. Specialized lubricants are also available and can be applied to both the nut and saddle to ensure smooth string movement, aiding in more stable tuning and accurate intonation adjustments.
Patience and Precision
While not a physical tool, patience and precision are crucial when adjusting guitar intonation. This process requires careful listening and incremental adjustments. Rushing can lead to overcompensation, resulting in further intonation issues. Take your time to make small adjustments, regularly checking the tuning and intonation with your electronic tuner. Being methodical and patient will yield the best results, ensuring your guitar is properly intonated and plays beautifully across the entire fretboard.
How Do You Prepare Your Acoustic Guitar for Intonation Adjustment?
Tune Your Guitar to Standard Pitch
Before making any adjustments to your guitar’s intonation, it’s crucial to tune your instrument accurately to standard pitch (EADGBE). Using a reliable electronic tuner, ensure each string is in perfect tune. This provides a baseline for assessing intonation and making precise adjustments. Accurate tuning ensures that any intonation issues you detect are due to the guitar’s setup rather than incorrect string pitches.
Check the Condition of Your Strings
Old or worn strings can significantly affect intonation. They may produce inconsistent pitches and are more likely to stretch unevenly. If your strings are old, it’s best to replace them with a fresh set before you start adjusting the intonation. New strings will settle more consistently and provide a more reliable reference for tuning and intonation adjustments. Make sure to give new strings a bit of time to stretch and settle before making your final adjustments.
Inspect the Guitar’s Neck
The neck of your guitar should be straight for proper intonation. Use a straightedge or simply sight down the neck from the headstock to the body to check for any bowing or warping. If the neck is not straight, you may need to adjust the truss rod. A bowed or warped neck can cause intonation issues that cannot be corrected simply by adjusting the saddle. Ensure the neck is as straight as possible to provide a stable foundation for accurate intonation adjustments.
Adjust the Action
The action, or the height of the strings above the fretboard, can impact intonation. If the action is too high, pressing the strings down to the frets can cause them to stretch more, leading to sharp notes. Conversely, if the action is too low, it might cause buzzing and unclear notes. Measure the action at the 12th fret using a ruler or feeler gauge and adjust it to the recommended height for your guitar. This adjustment can usually be made by raising or lowering the saddle or adjusting the truss rod. Proper action setup is essential for accurate intonation.
Clean the Nut and Saddle
Dirt and grime in the nut slots and on the saddle can affect string movement and intonation. Clean these areas thoroughly using a soft brush or cloth. You can also apply a small amount of graphite (from a pencil) or a specialized lubricant to the nut slots to ensure the strings move smoothly. This reduces friction and helps maintain consistent string tension, which is vital for accurate tuning and intonation.
Gather Your Tools
Ensure you have all the necessary tools on hand before you start adjusting the intonation. These include an electronic tuner, a screwdriver (appropriate for your guitar’s saddle screws), a string winder, and possibly a capo. Having everything ready will make the process smoother and more efficient. Additionally, find a quiet and comfortable workspace where you can focus on making precise adjustments without interruptions.
Warm Up the Guitar
Temperature and humidity can affect your guitar’s wood and metal parts, causing them to expand or contract. Before making intonation adjustments, it’s a good idea to let your guitar warm up to the ambient room temperature. Play the guitar for a few minutes to stabilize the temperature of the strings and body. This ensures that any adjustments you make are based on the guitar’s normal playing conditions, leading to more reliable and stable intonation settings.
How Do You Adjust the Intonation on the Low E String?
Checking the Intonation
To adjust the intonation on the low E string, you first need to determine if it is indeed out of tune along the fretboard. Start by tuning the open low E string (the 6th string) to the correct pitch using an electronic tuner. Once the string is in tune, play a harmonic at the 12th fret and note the pitch. Immediately after, press down on the 12th fret and play the fretted note. Compare the pitch of the harmonic and the fretted note. If the fretted note is sharp or flat compared to the harmonic, the intonation is off and needs adjustment.
Preparing for Adjustment
Before making any adjustments, ensure your guitar is stable and you are working in a comfortable, quiet environment. Place your guitar on a stable surface, like a workbench or a table, with a soft cloth or mat underneath to prevent scratches. Gather your tools: a screwdriver (appropriate for your guitar’s saddle screws), an electronic tuner, and possibly a capo to hold down other strings if needed.
Making the Adjustment
- Determine the Direction: If the fretted note at the 12th fret is sharp compared to the harmonic, the string length needs to be increased. If the fretted note is flat, the string length needs to be decreased.
- Adjust the Saddle:
- For acoustic guitars, this typically involves moving the saddle in the bridge slot. If your guitar has an adjustable saddle, use a screwdriver to adjust the screw at the bridge. Turning the screw clockwise will generally move the saddle back, increasing the string length. Turning it counterclockwise will move the saddle forward, decreasing the string length.
- If your guitar does not have an adjustable saddle, you may need to physically move the saddle in the bridge slot. This could involve slight sanding or shimming to change its position. This process is more delicate and may require professional help if you are unsure.
- Retune and Recheck: After making a small adjustment, retune the low E string to the correct pitch. Repeat the harmonic and fretted note test at the 12th fret. It may take several small adjustments to get the intonation perfect. Patience is key here, as rushing can lead to over-adjustment and further intonation issues.
Fine-Tuning the Adjustment
After the initial adjustment, it’s important to fine-tune. Play notes and chords up and down the fretboard, paying special attention to how the low E string sounds in different positions. If you notice any discrepancies, make minor adjustments as needed. Use your electronic tuner to ensure accuracy with each adjustment. This fine-tuning process ensures that the low E string is in tune across the entire fretboard, not just at the 12th fret.
Final Checks
Once you are satisfied with the intonation on the low E string, perform a final check:
- Play the open string, the 12th fret harmonic, and the 12th fret fretted note one last time to ensure they match perfectly.
- Play a few chords and scales to confirm that the intonation is consistent across different frets and positions.
- Check the intonation of the other strings as well, as adjusting one string can sometimes affect the others.
How Do You Adjust the Intonation on the Other Strings?
Checking the Intonation
Just like with the low E string, the first step in adjusting the intonation of the other strings is to check if they are in tune across the fretboard. Begin by tuning each open string accurately using an electronic tuner. Once the open strings are in tune, play a harmonic at the 12th fret and then compare it to the fretted note at the same fret. Note any discrepancies between the harmonic and the fretted note for each string.
Preparing for Adjustment
Ensure your guitar is stable and that you have a comfortable, quiet workspace. Place your guitar on a soft cloth or mat to prevent scratches. Gather your tools, including an electronic tuner and the appropriate screwdriver for your guitar’s saddle screws. If necessary, use a capo to hold down other strings while you work.
Adjusting the A String (5th String)
- Determine the Direction: If the fretted note at the 12th fret is sharp compared to the harmonic, the string length needs to be increased. If the fretted note is flat, the string length needs to be decreased.
- Adjust the Saddle:
- Use a screwdriver to adjust the saddle screw at the bridge. Turning the screw clockwise will generally move the saddle back, increasing the string length. Turning it counterclockwise will move the saddle forward, decreasing the string length.
- If your guitar does not have adjustable saddles, you may need to physically move the saddle in the bridge slot, which can involve slight sanding or shimming.
- Retune and Recheck: After making a small adjustment, retune the A string to the correct pitch. Repeat the harmonic and fretted note test at the 12th fret. Make further adjustments as necessary until the intonation is correct.
Adjusting the D String (4th String)
Repeat the same process as for the A string. Play the open D string and the harmonic at the 12th fret, then compare it to the fretted note at the 12th fret. Adjust the saddle position as needed to ensure the fretted note matches the harmonic.
Adjusting the G String (3rd String)
The G string often presents unique challenges due to its higher pitch and tension. Follow the same steps as before:
- Tune the open G string.
- Compare the 12th fret harmonic to the fretted note.
- Adjust the saddle position to correct any intonation issues.
Adjusting the B String (2nd String)
The B string can also be tricky due to its tension and frequency:
- Tune the open B string.
- Compare the 12th fret harmonic to the fretted note.
- Adjust the saddle as needed to ensure the fretted note is in tune with the harmonic.
Adjusting the High E String (1st String)
Finally, adjust the intonation of the high E string:
- Tune the open high E string.
- Compare the 12th fret harmonic to the fretted note.
- Adjust the saddle position to correct any discrepancies.
Fine-Tuning Each String
After making initial adjustments, it’s important to fine-tune each string. Play notes and chords up and down the fretboard, listening for any inconsistencies. Use your electronic tuner to check intonation at various frets. Make minor adjustments as needed to ensure that each string is perfectly intonated.
Final Checks
Once all strings have been adjusted:
- Play the open strings, the 12th fret harmonics, and the 12th fret fretted notes one last time to ensure they match perfectly.
- Play a variety of chords and scales to confirm that the intonation is consistent across the fretboard.
- Check for any impact on the other strings’ intonation after adjusting each string.
What Common Mistakes Should You Avoid When Adjusting Intonation?
Neglecting to Tune Strings Properly
One of the most common mistakes when adjusting intonation is not tuning the strings accurately before starting the process. Each string should be perfectly in tune to standard pitch (EADGBE) using a reliable electronic tuner. Without a precise baseline, any adjustments made will be inaccurate, leading to more frustration and further intonation issues. Always ensure your guitar is in perfect tune before checking and adjusting intonation.
Overlooking String Condition
Adjusting intonation with old or worn strings is another frequent mistake. Strings that are past their prime can produce inconsistent pitches due to uneven wear and stretching. This can make it difficult to achieve accurate intonation. Always check the condition of your strings before adjusting intonation and replace them if they are old or damaged. New strings will provide a more stable and reliable reference for tuning and adjustments.
Ignoring the Impact of Action and Neck Relief
High action (string height) and incorrect neck relief can significantly affect intonation. High action causes the strings to stretch more when pressed down, leading to sharp notes. Conversely, low action can result in buzzing and unclear notes. Before adjusting intonation, ensure that the guitar’s action and neck relief are set correctly. Use a ruler or feeler gauge to measure the action at the 12th fret and adjust the truss rod if necessary to straighten the neck.
Making Large Adjustments Too Quickly
Intonation adjustments should be made incrementally. Making large changes all at once can lead to overcompensation, causing more tuning issues. Patience is key: make small adjustments to the saddle position and retune the string before checking the intonation again. Repeat this process until the intonation is correct. This methodical approach ensures more accurate and stable results.
Not Using the Correct Tools
Using the wrong tools can damage your guitar or result in ineffective adjustments. For example, using a screwdriver that doesn’t fit the saddle screws properly can strip the screws or damage the bridge. Ensure you have the right tools for the job, including the appropriate screwdriver, an accurate electronic tuner, a string winder, and possibly a capo. Having the correct tools makes the process smoother and helps avoid potential damage.
Overlooking Environmental Factors
Temperature and humidity can affect your guitar’s wood and metal parts, causing them to expand or contract. Making intonation adjustments in an environment with fluctuating conditions can result in unstable tuning. Ideally, adjust intonation in a stable environment where the temperature and humidity are consistent. Let your guitar acclimate to the room’s conditions before starting the process to ensure accurate and lasting adjustments.
Failing to Recheck and Fine-Tune
After making initial adjustments, it’s crucial to recheck the intonation and make fine-tuning adjustments as needed. Some players mistakenly assume that one adjustment is enough, but intonation can be a delicate balance that requires multiple checks. Play notes and chords up and down the fretboard, listen for any inconsistencies, and use your electronic tuner to verify accuracy. Fine-tuning ensures that the intonation is consistent across the entire fretboard.
Ignoring the Interaction Between Strings
Adjusting the intonation on one string can sometimes affect the other strings. It’s important to check all the strings after making adjustments to ensure that the intonation is correct across the board. Some players neglect this step and end up with a guitar that’s only partially intonated. Regularly check each string’s intonation throughout the process to maintain overall balance.
Enjoyed this guide of ? Then be sure to check out our other instrument guides.
- Best Acoustic Guitars Under $1000
- Best Acoustic Guitars Under $500
- Best Digital Pianos Under $1000
- Best Subwoofers Under $500
- Best Sound Bars Under $500
- Best Baritone Acoustic Guitars
- Best Microphones for Acoustic Guitar
- Best Headphones for Bass
- Best Studio Monitors Under $1000
- Best Headset for PS5
- Best Endgame Headphone Less Than $2000