There are so many factors that affect the way that acoustic and electric guitars sound. But what about string height, otherwise known as the “action” of a guitar? Does it affect tone, or does it only impact playability?
In this article, I’ll run through exactly how and why string height affects the tone of a guitar, and why it’s important. So let’s get started!
The Quick Answer
String height (action) affects the tone of acoustic and electric guitars. The higher the string height, the better the sustain will be, and the more resonant and open your guitar will sound. You are also less likely to experience experience fret buzz.
However, a very high action can make the guitar harder to play, and create intonation problems, meaning your guitar will always sound out of tune.
Action (String Height) and Tone
The action of a guitar, simply refers to the height the strings are set at, above the fretboard. Since the strings are where the sound of a guitar actually originates, it’s no surprise that the height affects how they sound.
High action (string height) = more resonance and better sustain
So why is this the case?
To understand this properly, you need to get to grips with exactly how a guitar’s strings produce the tone.
Of course, when you pluck a string, this causes it to vibrate.
Well, when the string moves from one side, it pushes air to the side to create high pressure. And when it moves back the other way, it moves into an area of low pressure, where there is less air. These pressure changes radiate from the string until they hit something. This causes whatever is hit to vibrate as well.
With acoustic guitars the vibrations produce sound when they are transmitted to the saddle, then the soundboard and body and then the sound comes through the sound hole.
With electric guitars, the vibrations caused by the strings, which are the source of the sound, are detected by the pickups.
Linking it back to string height…
If the action is very low, then two things can happen:
- The sound waves hit the fretboard wood quickly, and dissipate. Hence their is less sustain and resonance, because the notes as much.
- If the action is so low that the strings hit the frets, then it causes buzzing to occur.
Action and Intonation
As well as affecting the overall tone of your guitar, the action also impacts the intonation.
Intonation basically refers to whether the guitar is in tune or not. If the intonation is incorrect, then the guitar will sound out of tune, no matter how much you mess with the tuner heads.
You can check the intonation of your guitar by playing a 12th fret harmonic and compare the pitch to a note at the 12th fret.
The intonation is affected by the length of the guitar string.
A high action (string height) can negatively impact the intonation of your guitar.
This is because, the higher the action, the further you need to press down to fret a note. So when you push down more, you’re essentially lengthening the string. This causes it to sound out of tune because you are pulling the string more than you should be.
High vs Low Action
Okay, so with all that in mind, let’s compare the pros and cons of high and low actions.
|Pros of High Action||Pros of Low Action|
|Reduces risk of fret buzz||Fewer intonation issues|
|Better resonance and sustain||Easier to fret notes|
When your guitar has a high action (string height), the tone will be more open, and you’ll have better resonance and sustain. You’re also less likely to experience fret buzz, since the strings are not as close to the frets so won’t hit them when they’re vibration.
All this is great right? So why doesn’t every guitar have a high action?
Well, there are two main drawbacks of a high action. Firstly, it can cause intonation problems, as we discussed in the section above.
But it can also make the guitar much harder to play. If the strings are too high above the fretboard, then you have to press much harder to fret them properly.
This can be difficult for new players, and make moving arounf the fretboard a much slower process, even for professionals. Guitarists who play quick riffs, barre chords, power chords, or shred, are most likely to experience the negative affect a high action has on playability.
Okay, so what about having the action super low. Well this can cause fret buzz, which sounds awfully annoying. It also makes you tone have less resonance and sustain, meaning it won’t sound as deep and full.
On the plus side, it’s much easier to fret notes when you have a low action, making it easier to play. Low actions also have less of an issue with intonation problems, compared to high actions.
So hopefully now you see that action height is a compromise.
What Should Your String Height Be?
You’re probably now wondering what your string height should be then, in order to get the best of both worlds.
Typically, acoustic guitars have an action of 7/64″ (2.8 mm) on the low E string, and 5/64″ (2 mm) on the high E string.
Electric guitars usually have an action of 3/32″ on the low E string and 1/16″ (1.6 mm) on the high E string.
Action (string height) is usually measured at the 12th fret.
Normally, acoustic guitars have a higher action because this allows them to sound more resonant and open, but this does make them harder to play.
The string height it higher at the low E string end, compared to the high E string end, because the low E is thicker, so needs more room to vibrate compared to the thinner strings.
Of course, your action height doesn’t have to be exactly this. You can adjust this to suit your personal preference.
How to Adjust the Action
So this leads us to this next point. How do you actually go about adjusting the action on your guitar to improve the tone, or increase playability.
In order to adjust the string height, you can adjust the following aspects of your guitar:
- Saddle height
- Bridge height
- Truss rod
- Nut height
Unless you really know what you’re doing, it’s best to take your guitar to an experienced luthier to alter the action. Otherwise, you risk damaging your guitar.