7 Effective Tips to Lower Action on an Acoustic Guitar for Improved Playability

Achieving optimal playability is crucial for any acoustic guitar enthusiast. One key aspect that greatly affects playability is the action of the guitar. Action refers to the height of the strings above the guitar’s fretboard. Of all the issues I see on a new student’s guitar, high action is probably the most common. A high action can make playing difficult, causing discomfort and hampering your overall performance. Hopefully, a newly purchased guitar will have the action already set up properly. In this blog post, we will explore seven effective tips to lower the action on an acoustic guitar, allowing for a smoother playing experience and improved sound quality.

1. Assess the Current Action:

Before attempting to adjust the action on your acoustic guitar, it’s important to evaluate its current state. Examine the gap between the strings and the fretboard. If it appears too high, this indicates a need for action adjustment. Conversely, if the strings are too close to the frets and produce a buzzing sound, you may need to raise the action slightly.

These steps guide you on how to assess the current action of a guitar:

1. Get a ruler or action gauge. A ruler or action gauge is a tool that can be used to measure the distance between the strings and the fretboard.
2. Place the ruler or action gauge on the 12th fret. The 12th fret is a good place to measure the action because it is halfway between the nut and the bridge.
3. Measure the distance between the bottom of the string and the top of the fret. The measurement should be taken from the side of the string that is closest to the fretboard.
4. Repeat the measurement for each string. The action should be the same for all of the strings.
5. Compare the measurements to the manufacturer’s specifications. The manufacturer’s specifications will tell you what the ideal action is for your guitar.

Here are some additional tips for assessing the current action of a guitar:

• Play the guitar while you are measuring the action. This will give you a better idea of how the action feels when you are playing.
• Be sure to measure the action at both the nut and the bridge. The action may be different at each location.
• If you are not sure how to measure the action, you can take your guitar to a qualified technician. They will be able to measure the action and make sure that it is set correctly.

These other factors affect the action of a guitar:

• The type of guitar. The action will be different for different types of guitars, such as acoustic guitars, electric guitars, and bass guitars.
• The string gauge. The action will be higher with thicker strings and lower with thinner strings.
• The neck relief. The neck relief is the amount of bow in the neck. A guitar with too much neck relief will have high action, while a guitar with too little neck relief will have low action.
• The nut and bridge saddles. The nut and bridge saddles are the pieces of material that the strings rest on. The height of the nut and bridge saddles can affect the action.

2. Understand Truss Rod Adjustment:

A truss rod is a rod that runs through the neck of a guitar. It is used to counteract the tension of the strings and allow the player to adjust how much (or how little) the neck bows. There are two kinds of truss rods: single action and dual-action.

• Single-action truss rods: Only threaded on one end, allowing you to adjust the neck relief by turning the rod clockwise to straighten the neck and counterclockwise to allow the neck to bow forward.
• Dual-action truss rods: Threaded on both ends, allowing you to adjust the neck relief and also the amount of back bow in the neck.

To adjust the truss rod, you will need a truss rod wrench. The truss rod wrench is a small, Allen wrench that fits into the truss rod adjustment hole. The hole is usually located on the headstock of the guitar, near the nut.

To adjust the truss rod, you will need to loosen the strings. This is important because if the strings are too tight, you could damage the truss rod. Once the strings are loose, you can insert the truss rod wrench into the hole and turn it clockwise or counterclockwise.

• Clockwise: Tightens the truss rod, which straightens the neck.
• Counterclockwise: Loosens the truss rod, which allows the neck to bow forward.

How Far to Turn the Truss Rod

How much you turn the truss rod will depend on how much you need to adjust the neck relief. A good starting point is to turn the truss rod 1/8 of a turn at a time. If you turn the truss rod too much, you could overcorrect the neck relief and make the problem worse.

After you have adjusted the truss rod, you will need to tune the strings back up. Once the strings are tuned, you should check the neck relief again. If the neck relief is still not correct, you may need to adjust the truss rod again.

It is important to note that adjusting the truss rod can be a delicate process. If you are not sure how to adjust the truss rod, it is best to take your guitar to a qualified technician. They will be able to adjust the truss rod and make sure that it is set correctly.

Here are some tips for adjusting the truss rod:

• Make small adjustments. It is better to make small adjustments and then check the neck relief again than to make a large adjustment and risk overcorrecting the problem.
• Be patient. It may take a few adjustments to get the neck relief just right.

Bridge Saddle Adjustment:

The bridge saddles on an acoustic guitar are the pieces of material that the strings rest on. The height of the bridge saddles can affect the action of the guitar. If the bridge saddles are too high, the action will be high, and it will be difficult to play the guitar. If the bridge saddles are too low, the action will be low, and the strings may buzz against the frets.

Adjustable Bridges

Some acoustic guitars have adjustable bridges. To adjust the height of the bridge saddles on an acoustic guitar, you will need a small Allen wrench or screwdriver. The size of the Allen wrench or screwdriver will depend on the type of bridge saddles you have.

To adjust the height of the bridge saddles, you will need to loosen the Allen screws or nuts that hold the saddles in place. Once the screws or nuts are loose, you can use the Allen wrench or screwdriver to raise or lower the saddles.

• To raise the saddles, turn the Allen screws or nuts clockwise.
• To lower the saddles, turn the Allen screws or nuts counterclockwise.

How much you raise or lower the saddles will depend on how much you need to adjust the action. A good starting point is to raise or lower the saddles 1/16 of an inch at a time. If you raise or lower the saddles too much, you could overcorrect the action and make the problem worse.

After you have adjusted the height of the bridge saddles, you will need to tune the strings back up. Once the strings are tuned, you should check the action again. If the action is still not correct, you may need to adjust the bridge saddles again.

Proceed with Caution

It is important to note that adjusting the bridge saddles on an acoustic guitar can be a delicate process. If you are not sure how to adjust the bridge saddles, it is best to take your guitar to a qualified technician. They will be able to adjust the bridge saddles and make sure that they are set correctly.

Here are some tips for adjusting the bridge saddles on an acoustic guitar:

• Make small adjustments. It is better to make small adjustments and then check the action again than to make a large adjustment and risk overcorrecting the problem.
• Be patient. It may take a few adjustments to get the action just right.
• If you are not sure how to adjust the bridge saddles, take your guitar to a qualified technician.

Non-Adjustable Bridges

If your guitar does not have an adjustable, then follow these steps to file or sand down a bone/synthetic saddle of an acoustic guitar:

1. Gather your materials. You will need a file or sandpaper, a ruler, and a pencil. You may also want to wear safety glasses to protect your eyes from flying debris.
2. Measure the height of the saddle. Use the ruler and pencil to measure the height of the saddle at the 12th fret. This is the height that you will be trying to achieve.
3. File or sand the saddle. Use the file or sandpaper to file or sand the saddle down until it is the desired height. Remember to file only the bottom of the saddle. The top is usually compensated. Be careful not to sand too much, or you will affect the intonation of the guitar.
4. Check the action. Once you have filed or sanded the saddle, check the action of the guitar. The action should be low enough that the strings do not buzz against the frets, but high enough that you can still play the guitar comfortably.
5. Repeat as needed. If the action is not correct, you may need to file or sand the saddle again. Be patient and take your time, and you will eventually get the action just right.

Here are some additional tips for filing or sanding down a bone saddle of an acoustic guitar:

• Use a fine-grit file or sandpaper. This will help to prevent the saddle from chipping or cracking.
• Work slowly and carefully. It is better to take your time and file or sand the saddle a little bit at a time than to rush and file or sand too much.
• Check the action frequently. As you file or sand the saddle, be sure to check the action frequently to make sure that you are not sanding too much.
• If you are not comfortable filing or sanding the saddle yourself, take your guitar to a qualified technician. They will be able to file or sand the saddle for you and make sure that it is done correctly.

Here are some additional considerations when adjusting the bridge saddles on an acoustic guitar:

• The type of bridge saddles. Acoustic guitars can have different types of bridge saddles, such as compensated saddles or non-compensated saddles. Compensated saddles are designed to improve intonation, while non-compensated saddles are not. If you are not sure what type of bridge saddles you have, it is best to consult with a qualified technician.
• The string gauge. The string gauge will also affect the action of the guitar. Thicker strings will have higher action, while thinner strings will have lower action. If you are changing the string gauge on your guitar, you may need to adjust the bridge saddles to compensate for the change in action.
• The nut height. The nut height is also important for the action of the guitar. If the nut height is too high, the action will be high, and it will be difficult to play the guitar. If the nut height is too low, the strings may buzz against the frets. If you are adjusting the bridge saddles, you may also need to adjust the nut height to get the action just right.

3. Nut Height Considerations:

The nut, situated at the top end of the neck, also affects the action. If the nut slots are too high, it can lead to increased action. You can lower the nut slots by carefully filing them down. However, exercise caution to avoid going too far, as this can lead to string buzzing. For complex adjustments, it’s advisable to consult a professional guitar technician.

4. String Gauge Selection:

The choice of string gauge has a noticeable impact on the action of an acoustic guitar. Lighter gauge strings exert less tension on the neck, resulting in lower action. Consider experimenting with different string sets to find the right balance between tone and playability. Keep in mind that changing the string gauge may require further adjustments to maintain proper intonation.

5. Climate and Humidity Control:

Changes in temperature and humidity can affect the wood’s moisture content, leading to neck adjustments and changes in action. To minimize such variations, store your guitar in a controlled environment, avoiding extremes of temperature and humidity. Using a humidifier or dehumidifier can help maintain a stable moisture level, preserving the guitar’s playability.

6. Seek Professional Assistance:

If you are uncertain or uncomfortable with adjusting the action yourself, it’s always advisable to seek the expertise of a professional guitar technician or luthier. The one I recommend most often in the Charleston area is Bill Reilly at Lowcountry Luthiery. He’s done good work on my and my students’ instruments. They possess the knowledge and experience necessary to optimize the action while ensuring the guitar’s integrity is maintained.

7. Recommended Height from Martin, Taylor, and Gibson

The three most notable guitars in the world are Martin Guitars, Taylor Guitars, and Gibson Guitars. They all fall into the same general guidelines from the factory and custom shops. The table below shows the ranges for the low and high E strings on acoustic guitars.

Speaking of Gibson Guitars, the video by Gibson Guitars below gives some valuable insight into adjusting your action.

Conclusion:

Lowering the action on an acoustic guitar is a valuable technique for enhancing playability and achieving better sound quality. By following these seven effective tips, you can make adjustments to the truss rod, bridge saddle, nut, and string gauge, as well as take necessary precautions to maintain a stable climate for your instrument. Remember, it’s crucial to approach any action adjustments with care and precision, and when in doubt, consult a professional.

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Chadwick Becks

I have two degrees in guitar performance and was privileged to study under Aaron Shearer, Tom Kikta, David Skantar, Ken Karsh, Tim Bedner, and currently Christopher Berg. Outside my editorial work on this blog, I teach full-time across many genres including classical, jazz, blues, rock, funk, and metal.