How to Lower the Action on an Acoustic Guitar? – 3 Ways…

Last Updated on August 19, 2023 by Teemu Suomala

Author: Teemu Suomala

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I first grabbed the guitar in 2009. I started this website in January 2020 because I couldn’t do window installation anymore due to my health problems. I love guitars and have played dozens and dozens of different guitars through different amps and pedals over the years, and also, building a website interested me, so I decided to just go for it! I got lucky and managed to get awesome people to help me with my website.

I also got lucky because I have you visiting my website right now. Thank you. I do all this for you guys. If you have any recommendations, tips, or feedback, just leave a comment, I would love to chat with you. I have also been fortunate to produce content for several large guitar websites, such as Songsterr, Musicnotes, GuitarGuitar, and Ultimate Guitar.

I spend my spare time exercising and hanging out with my wife and crazy dog (I guess that went the right way…).

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If you think that an acoustic guitar can’t hurt you? Haha! Think again. Sometimes, playing this musical instrument can result in painful moments, and yes, fingers, thanks to a string action that is not spot-on. 

A guitar’s action can be helpful or detrimental to one’s playing. When it’s too high, it’s hard to play the chords perfectly, while when it’s too low, you also get that annoying buzz sound that can be irritating to listen to for some.

Thankfully, there is a way to deal with the issue, and it is not too much of a headache.

It is good that you are here, as we intend to make your playing more comfortable than before! Relax, read, learn, and enjoy as we take your guitar knowledge to a new level!

What Is Guitar Action?

Guitar action refers to the strings’ distance above the guitar’s fret wires. It is a crucial factor for guitar players, affecting playability, tone, and overall performance.

Check out our ultimate guide here if you want to learn more about guitar action.

Why Is Action Important For Acoustic Guitar Players?

For acoustic guitarists, finding the right action is crucial for a comfortable playing experience and optimal tone. A low action makes playing easier, allowing for faster playing and reduced finger fatigue. 

However, setting it too low can result in buzzing and poor sustain. On the other hand, a higher action can provide better sustain but requires more finger strength to play. 

Striking the right balance in action height ensures a guitar that is easy to play and produces the desired tone, making it a key consideration for acoustic guitar players.

How to Lower the Action on an Acoustic Guitar?

Lowering The Action: Three Steps In Getting It Done

When your acoustic guitar is too painful and uncomfortable to play, it would be the perfect time to lower its action. 

But how? Lowering the guitar action involves making adjustments to reduce the height of the strings above the fretboard. Here are three common steps involved in lowering the guitar action:

1. Truss Rod Adjustment: You loosen the truss rod to allow the neck to straighten, reducing the bow or relief.

2. Nut Adjustment: It is where you file or sand the nut slots slightly deeper to reduce the strings’ height at the nut.

3. Bridge Saddle Adjustment: You file or sand down the bottom of the saddle evenly to lower its height, thereby lowering the action.

What Tools You Need for Lowering Acoustic Guitar Action

Remember that just bare hands can’t lower the guitar’s action. Therefore, if you plan to lower your guitar’s action, you’ll need these tools to accomplish what you are aiming for: 

• Allen wrenches – Many acoustic guitars have an adjustable truss rod accessed through the soundhole or the headstock. An appropriate-sized Allen wrench is needed to adjust the truss rod, which can help with neck relief and overall action.

• Screwdriver – Some acoustic guitars have adjustable saddle height through screws or bolts. A screwdriver may be required to loosen or tighten these screws to adjust the saddle height.

• Sandpaper or fret file – If the action needs to be lowered further, you may need to modify the saddle or the bottom of the bridge. Sandpaper or a fret file can remove material from the saddle, allowing it to sit lower and reduce the action. Be cautious when using these tools to avoid removing too much material.

• Feeler gauges – Feeler gauges are thin strips of metal used to measure the gap between the strings and the frets. They can help ensure consistent action height across the fretboard and assist in achieving the desired action.

• String height gauge or ruler – A ruler or specialized string height gauge can measure the action at different points along the fretboard. This allows you to track the changes and ensure an even action.

• Capo – A capo can simulate the pressure of a finger on the fret, allowing you to test and adjust the action while playing chords or individual notes.

• Guitar tuner – It’s always helpful to have a tuner on hand to ensure accurate intonation and pitch when adjusting the guitar’s action.

Step 1: Adjusting the Truss Rod

Note: I recommend always starting by checking if a truss rod needs some adjusting since that’s easiest to adjust with acoustic guitar and usually will do the trick.

Before we adjust the truss rod, you should know what is a truss rod first. It is a metal rod embedded in the neck of a guitar, running along its length. It is adjustable and counteracts the tension exerted by the strings, helping to control the neck curvature and maintain its stability. 

The truss rod plays a crucial role in adjusting the neck curvature and, in turn, the string height on a guitar. Adjusting the truss rod counteracts or releases the tension of the strings, causing the neck to develop relief and resulting in the adjustment of the strings’ height. 

The neck’s curvature can be adjusted by tightening or loosening the truss rod. To locate the truss rod nut, look for a small access point on the headstock or inside the guitar’s soundhole. It is typically hexagonal (hex) shaped, and you can adjust it using an appropriate tool, such as an Allen or truss rod wrench.

Do you want to know more about truss rods? Check our ultimate truss rod guide here.

How To Check The Straightness Of A Guitar’s Neck

Before we go to adjust the guitar’s truss rod, you should check first the guitar neck’s straightness and determine whether it needs to be straightened out. Here are some of the ways to do it:

• Visual inspection – Look down the length of the neck from the headstock to the body while holding the guitar in a playing position. Focus on the alignment of the fretboard and observe if it appears straight or if there is a noticeable bow or curvature. While this method can provide a general indication, it may not reveal subtle issues.

• Fretting technique – Press down the strings simultaneously at the first and last fret, usually with your thumb and pinky finger. While doing so, observe the gap between the strings and the frets around the middle of the neck. If the gap is consistent, the neck is likely straight. If gaps in the center of the strings touch the frets, there may be excessive relief (upward curvature). If there is a large gap between the strings and the frets, there may be excessive back-bow (reverse curvature).

If you don’t have a long ruler (I recommend buying one), you can also press your string down from the 1st fret and from the 15th fret(this with your pinky), and then use your hand pressing the 15th fret to press frets directly from the fret wire towards the neck of the guitar. If you can feel that there’s a gap between the fret and string, your guitar’s truss rod most likely needs some adjusting. This method of testing neck relief is also referred to as the “tap test“.

• Using a straightedge or ruler – Place a straightedge (such as a metal ruler or specialized straightedge tool) against the guitar’s frets. Start from the first fret and extend it towards the body, checking for visible gaps between the ruler and the frets. The neck is relatively straightforward if the ruler touches multiple frets without gaps. If there are gaps between the ruler and the frets, it indicates a bow or curvature.

How To Adjust The Truss Rod Correctly

For a newbie, adjusting a guitar’s truss rod is challenging, so it is highly recommended that you ask a guitar technician to do it for you. However, if you are confident in your abilities, here are some tips to help you adjust the truss rod correctly:

• Understand the direction: Turning the truss rod clockwise (righty-tighty) tightens it, reducing the neck’s relief or creating a back-bow. Turning it counterclockwise (lefty-loosey) loosens the truss rod, increasing the neck’s relief or allowing for more curvature.

• Make small adjustments: Start with minor quarter-turn adjustments and evaluate the results before making further changes. Gradual adjustments help prevent overcompensation, allowing the wood to adapt gradually to the new tension.

• Give it time to settle: After each adjustment, give the guitar time to settle. Changes in neck relief may take hours or even days to fully manifest. Monitor the guitar’s playability over time to determine if additional adjustments are necessary.

Adjusting the truss rod is one of the most basic methods for lowering your guitar’s action, so it should be executed carefully and appropriately to avoid damaging the guitar in the long run.

Step 2: Adjusting the Nut

A guitar nut is a small, usually rectangular-shaped component at the top of the guitar’s neck. The nut on acoustic guitars is generally made of bone or plastic. The nut has slots or grooves where the strings rest, determining their spacing and height above the fretboard. It helps maintain proper string alignment, spacing, and tension, contributing to accurate intonation and playability.

The guitar nut plays a crucial role in determining the string height at the first fret. If the nut slots are too high, the strings will be elevated, resulting in higher string height and potentially causing intonation and playability issues. Properly filing or adjusting the nut slots ensures the correct string height at the first fret for comfortable and accurate playing.

How To Check The Action At The Nut

When preparing to adjust the nut, you should first check the guitar’s current action at the nut by using either a feeler gauge or a capo.

Using a feeler gauge:

1. Start by detuning the strings slightly to relieve tension.
2. Place the appropriate feeler gauge, typically between 0.010-0.020 inches (0.25-0.50mm), on top of the first fret.
3. Press the string at the third fret while keeping the feeler gauge in position.
4. Check the gap between the bottom of the string and the top of the second fret. This gap represents the current action at the nut.

Using a capo:

1. Position the capo on the first fret, just behind the desired string.
2. Press the string down at the third fret.
3. Observe the gap between the bottom of the string and the top of the second fret. This distance indicates the current nut action.

Using either method, you can assess the strings’ height at the nut and determine if any adjustments are necessary to achieve the desired action. Remember to measure each string individually, as they may have different measurements and require individual adjustments.

How To Lower The Action At The Nut

Lowering the action at the nut can be done by filing or sanding down the nut slots, but this requires precision and caution. Here’s a step-by-step guide using a nut file or a needle file:

1. Loosen the strings: Begin by detuning the strings slightly to relieve tension. This will make it easier to work on the nut slots.
2. Choose the appropriate file: Select a nut file or a needle file that matches the width of the string gauge. Ensure the file is clean and sharp for accurate and smooth filing.
3. File the nut slots: Gradually and lightly file/sand the bottom of each nut slot, following the original angle of the slot. File/sand in a back-and-forth motion to remove material evenly. Take gradual and light passes when filing or sanding the nut slots. It’s better to remove a small amount of material and make multiple passes than to remove too much in one go.
4. Regularly check the action: Retune the strings and assess the action at the nut after each filing or sanding pass. This allows you to monitor the progress and avoid going too far. Removing more material, if necessary, is easier than adding it back.
5. Smooth the nut slots: After achieving the desired action, use fine sandpaper or a small file to carefully smooth the nut slots. This ensures the strings can move freely without rough edges or catching.

Remember, working on the nut requires precision and care, so if you are not confident, always ask for a professional’s help.

Step 3: Adjusting the Saddle

Unfamiliar with the word “saddle?” If you think about horses, then you are wrong. A guitar saddle is a small piece of bone, plastic, or metal located on the bridge, which helps support and position the strings for proper intonation.

The guitar saddle can be adjusted to control the strings’ height at the bridge. Raising or lowering the saddle affects the action or string height, which can impact the instrument’s playability, tone, and intonation. 

How To Check The Action At The Saddle

Rather than adjusting immediately, check first the current action of the acoustic guitar’s saddle to determine if it needs to be modified by following these steps: 

1. Loosen the strings.
2. Place a ruler or string action gauge on top of the 12th fret.
3. Press down the 1st and 14th frets.
4. Measure the distance between the bottom of the ruler/ gauge and the top of the 6th string.
5. Note the measurement in millimeters or inches.
6. Repeat for the 1st string.
7. Compare measurements to guidelines or preferences (For acoustic guitars, a typical range is around 2.4mm to 2.8mm for the low E string at the 12th fret)
8. Adjust the saddle height if needed.
9. Recheck the action after adjustments.

How To Lower Action At The Saddle

To lower the action at the saddle, you can do it by following these steps:

1. Loosen the strings by turning the tuning pegs.
2. Use pliers to gently lift and remove the saddle from the bridge slot.
3. Place sandpaper (grit side up) on a flat surface and rub the bottom of the saddle evenly to remove the material.
4. Reinstall the saddle into the bridge slot.
5. Tune the strings back to pitch and check the action. Repeat steps 3-5 if further adjustment is needed, removing material gradually.

Be careful and don’t sand the saddle to much. Since saddle adjusmtents done wrong can cause fret buzz or ruin the intonation. If this happens, you most likely have to replace the saddle with a new one.

It is always important to exercise caution while removing material from the saddle, as removing too much can impact the saddle’s structural integrity. It is also recommended to mark the amount of material to be removed to have a better guide in executing the task.

Pros and Cons of Lowering Acoustic Guitar Action

Of course, lowering the action on an acoustic guitar can have both pros and cons, and here are some of them:

Pros:

1. Improved playability: Lower action makes it easier to press down the strings, reducing finger fatigue and allowing for faster, smoother playing.

2. Reduced string buzz: Lowering the action can minimize unwanted string buzz, resulting in clearer and cleaner notes.

3. Enhanced intonation: Lower action can improve intonation by minimizing the string’s stretching and bending when fretted.

Cons:

1. Potential for fret buzz: If the action is lowered too much, it can cause buzzing against the frets, resulting in a loss of sustain and clarity.

2. Reduced string volume: Lower action may decrease the overall volume and projection of the guitar due to decreased string-to-soundboard interaction.

3. Sacrifice in tone: Very low action can affect the resonance and tonal quality of the guitar, potentially leading to a loss of depth and richness in sound.

Check The Intonation of An Acoustic Guitar

Checking the guitar’s intonation after lowering the action is crucial because altering the action can affect the length and tension of the strings, potentially causing changes in intonation.

Starting on the low E string, play the 12th-fret harmonic and compare it to the actual fretted note on the 12th fret with a tuner. If the fretted note is sharp or flat compared to the harmonic, you’ll need to make some saddle position adjustments for that string.

Adjusting the action may require subsequent adjustments to the bridge saddle to maintain an accurate pitch across the fretboard. With electric guitars, this really simple. Just adjust some intonation screws.

With acoustic guitars, intonation adjustments are not that easy. There are some quick tricks you can do like the one revealed in this video. But if you want more permanent fixes, letting a luthier handle the intonation setup is wise.

If you want to know more about a guitar’s intonation, check out our ultimate guitar intonation guide here.

FAQ

Conclusion on Lowering Action of An Acoustic Guitar

Being comfortable with your gear is an important part of you getting better at guitar playing.

So, if your acoustic guitar feels hard to play, check its action. First, the neck’s straightness, the nut’s height, and lastly, the saddle’s height. Make the necessary adjustments if necessary. Remember always to be careful to avoid aggravating the problem. Sometimes letting a luthier/guitar tech handle the adjustments is wise.

Remember that having a spot-on action makes playing more comfortable, allowing you to do your best with your abilities without feeling any pain. Not too high and not too low, just the right distance. Enjoy playing with a new sense of comfort!

If you have any questions, leave a comment, we are here for you.

Keep rocking!

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