how to reduce action on acoustic guitar

3 min read 24-01-2025

Acoustic guitar action refers to the distance between the strings and the frets. High action makes playing difficult, causing discomfort and potentially hindering your playing. Low action, conversely, can lead to buzzing. Finding the sweet spot is crucial. This guide will walk you through how to reduce high action on your acoustic guitar.

Assessing Your Guitar's Action

Before you start adjusting anything, you need to determine if your action is truly too high. High action is generally characterized by:

String height at the nut: Measure the distance from the top of the first fret to the bottom of the strings at the nut (the bone or plastic piece at the end of the fingerboard). A good starting point is around 1/16" to 1/8" for the bass strings and slightly less for the treble strings. Specifications vary slightly by guitar model, so check your guitar's manual if possible.
String height at the 12th fret: This is a more critical measurement. Use a ruler to measure the distance from the top of the 12th fret to the bottom of each string. Ideally, this should be around 3/32" for the bass strings and slightly less for the treble strings. Again, consult your guitar's manual for specific recommendations.
Difficulty playing: If you find it difficult to fret notes cleanly, especially on the higher frets, or experience excessive string tension, high action is likely the culprit.

Methods to Reduce Acoustic Guitar Action

There are several ways to reduce action, ranging from simple adjustments to more involved repairs:

1. Adjusting the Bridge Saddle

The bridge saddle is a small piece of material (often bone, plastic, or graphite) under the strings at the bridge. Lowering it is the most common way to reduce action.

Caution: Lowering the saddle too much can lead to buzzing. Proceed slowly and carefully.
Process: You'll need a saddle-height adjustment tool or a small, sharp file. Carefully remove the saddle (some are glued, others are held in place by string tension). Use the tool or file to shave off a tiny amount of material from the bottom of the saddle. Reinsert and test. Repeat until you reach the desired action.

2. Adjusting the Truss Rod (Neck Relief)

The truss rod is a metal rod inside the neck that affects the neck's curvature (relief). A backbowed neck (too much relief) contributes to high action.

Caution: Incorrect truss rod adjustment can damage your guitar. If you're unsure, consult a professional luthier.
Process: Access the truss rod (usually located at the headstock or heel of the neck). Use the appropriate wrench to make small adjustments. Turning it clockwise usually increases neck relief (making it straighter), while counterclockwise decreases relief (creating a more curved neck). Check the neck relief after each small adjustment. A properly adjusted neck should have a slight concave curve (relief) when viewed down the neck.

3. Filing the Nut

A high nut can also contribute to high action. Filing the nut slots is a more advanced technique.

Caution: Filing the nut incorrectly can damage it. It is advisable to have this done by a luthier.
Process: This requires specialized tools and careful measurement. The slots need to be deepened slightly to lower the string height at the nut. Improper filing can severely damage your guitar.

4. Replacing the Nut or Saddle

If adjusting the existing nut and saddle isn't enough, or if they're damaged, replacement might be necessary.

Process: This is a job best left to a professional luthier. They can accurately shape and fit replacement parts to your guitar.

When to Seek Professional Help

If you're uncomfortable making adjustments yourself, or if you've tried the above methods without success, it's best to take your guitar to a qualified luthier. They have the expertise and tools to diagnose the problem and make the necessary repairs or adjustments accurately and safely. Attempting complex repairs without experience can cause irreparable damage.

Remember to always approach adjustments gradually. Small changes are better than drastic ones. Test after each adjustment to avoid overdoing it and potentially harming your instrument. Maintaining proper action ensures your guitar plays comfortably and sounds its best.