Guitar action is an incredibly important aspect of a guitar setup. First and foremost, it affects comfort and playability but also plays a role in potential string gauge options and may even affect the guitar's overall tone.
Does guitar action/string height affect tone? Guitar action (the height between the frets and the strings) affects tone and playability, which also ultimately affects tone. Higher action allows for greater vibration, which allows for more volume and sustain in the tone. Lower action reduces volume and sustain but may offer improved playability, which is equally as important as tone.
In this article, we'll discuss guitar action and how it affects tone in greater detail to deepen our understanding of guitars and stringed instruments in general.
What Is Guitar Action?
Guitar action refers to the distance between the top of a guitar's frets and the bottom of the guitar's strings. More specifically, action is measured at the 12th fret of the lowest string.
Action plays a major role in the playability of a stringed instrument. Generally speaking, higher action will be more difficult to play since we must press harder to fret the string. This additional effect makes it more challenging to play fast and more tiresome to hold chords, for example.
If the action is too low, the strings are liable to touch frets above the fingered fret, causing buzzing in most cases and even unintended notes, in particularly bad cases.
So a close action just shy of buzzing is often optimal for players. Of course, action is largely down to taste, and some players actually prefer high action. The greater the string vibration, the greater the possibility for string buzz, so more aggressive players may benefit from slightly high action.
In addition to affecting playability, guitar action will also affect the tone (beyond buzzing). Let's get into why this is the case.
Does Guitar Action/String Height Affect Tone?
Many factors affect the guitar's sound, from the strings' build to the guitar's architecture. Another determinant is how the strings interact with the rest of the instrument and their spatial relation to the instrument, which is largely related to action.
All stringed instruments, including guitars, produce sound and notes via vibrating strings. These strings vibrate as they are plucked, struck or bowed. In the case of guitar, the strings are typically plucked, either by a pick or the fingers.
Though string vibrations will produce sound by themselves, they typically must be amplified to produce practical levels of audible sound.
Acoustic guitars have a soundbox that functions as the amplifier. In contrast, electric guitars use pickups, which convert the vibrations to audio signals for later electrical amplification and reproduction of sound through a loudspeaker (or headphones).
The space between the fretboard and the string defines how the string will vibrate and, consequently, how the sound wave will make its way to the bridge.
If the string is high with respect to the fretboard (high action), it can deliver a more resonant note with a longer sustain. The string itself has more physical space to oscillate about its resting position, thereby improving the guitar's potential volume and sustain.
Conversely, if the string is too close to the fretboard (low action), it will be more constrained and, likewise, will be hindered by the frets. The string won't be able to oscillate as much about its resting position and may even touch other frets, which will absorb some energy and even cause buzzing. The result is a tone with worse sustain and overall volume.
Furthermore, in electric guitar, higher action may result in the strings being further from the pickup (if the pickup height is not adjusted). While a closer distance between the strings and pickups will improve volume output, it also affects tone.
Since guitar pickups and strings are both magnetic (this is required for the pickups to work as transducers), the pickups will have a magnetic pull on the strings. The closer the pickups and strings, the more this magnetic pull and the more unnatural the strings' vibration will be. A higher action, in this case, could allow for freer vibration within the strings and, therefore, a more natural tone.
To learn more about how the distance between the strings and pickups of an electric guitar will affect tone, check out my article How Does Guitar Pickup Height Affect Tone?
There are benefits to a higher setup. The most notorious, as explained above, is the ability of the string to deliver a fuller sound. The other one, closely related to the first, is that you won't experience as much fret buzz as with a lower setup.
The disadvantages are mostly in terms of playability. As you'll need to maneuver the fretting with far more precision to be able to play any note, those guitarists who crave fast shredding and sweep picking will be left a bit disappointed. This is not to say that it's not possible to play these higher-action guitars at faster tempos, but they will demand far more skill. Also, the thinner the gauge is, the more difficult it will be to fret strings at high action.
Note that because action is technically measured between the top of the fret and the bottom of the string (rather than the centre or top of the string), string gauge isn't necessarily part of action. That being said, the tone is affected by the string gauge.
To learn more about how guitar strings and string gauge affects tone, check out my article How Do Guitar Strings Affect Tone? (Acoustic, Electric, Bass).
High Action Guitar Tone
To reiterate, high guitar action tends to offer a more resounding and sustaining tone thanks to freer vibration. The strings have the space to vibrate at great amplitudes of oscillation, which typically translate to greater volume from the guitar's soundboard and body or pickups.
Low Action Guitar Tone
Low guitar action tends to cause less volume and sustain in the guitar tone due to restricted vibration. The strings have less space to vibrate and, therefore, oscillate with less amplitude. This typically translates to lower volume from the guitar's soundboard and body or pickups.
The Mechanics In Depth
In most cases, guitars have three main sections: head, neck, and body. The head is where we'll find the tuning pegs. The neck and body are the two sections where most of the action takes place, for the strings run across them as they find their resting places in both the nut at the top and the bridge fixed at the bottom.
When the string is plucked, it oscillates from one side to the other at a speed relative to the tension. This oscillation can vary in radius, that is, the distance between the center and the outmost point of the movement.
As a general principle, the higher the tension, the lower the radius. High notes produce lower vibration radius and higher vibration frequency, allowing the soundwaves to travel faster and produce higher-frequency sounds. Treble strings normally produce higher vibration frequency and lower radius, allowing them to fit more easily on lower altitudes.
On the contrary, bass strings (the ones that render the lowest notes) suffer more when they're too close to the fretboard because they require more space to vibrate than treble strings. When they're too low, they will surely be thwarted by the frets and produce a buzzing sound that encumbers the integrity of the note played.
Guitar manufacturers often find a balance between sound fidelity and playability. Electric guitars, especially modern ones, are made to allow for faster playing, which justifies the narrower distance between the frets and the strings. They're also commonly built to fit lighter gauge strings, which are less prone to fret buzzing. As far as resonance goes, since the process is mostly electronic, the pickup and amplifier can account for the strings' lack of strength in this regard.
On the other hand, classical guitars are usually built with higher action since their resonance depends more heavily on mechanical components than electric ones. A lower action on a classical guitar is not ideal since it relies on the more rudimentary soundbox to make the sound audible.
Other Factors That Affect Tone
The height or action is not the only culprit when it comes to unappealing sound rendering. If your action is high, but the guitar top or the soundboard is not hollow enough, the sound transmission will suffer (which is why it's not recommended to put stickers on it.)
Another very important aspect to consider is the strings themselves. If they're corroded or old, no matter how high the action is, they won't be able to deliver a clear, buzz-free sound since fretting will be harder, notes will be semi-opened, and fingers will interfere in the vibration. The sound will be far weaker since the string lacks the strength and solidity to push the air around them.
Finally, skill plays a crucial role. It's not to say there aren't handicaps to be found on higher-action guitar. Still, when a guitarist neglects to practice his/her fretting, eventually, they'll find it frustrating to play at a higher height since the fingers haven't developed the necessary strength and precision to push the strings against the fretboard and, thus, they end up producing muted notes.
Higher action does not automatically equate better quality. Surely, tone improves technically with higher action. Still, too much height unquestionably affects tone quality (in a bad way) when taken in tandem with other elements such as playing style, the type of guitar, its quality, the soundbox's construction, and the string's gauge or length.
All of this also hinges on the player and what they find more comfortable. Guitar players who are used to playing lower-action guitars may find higher-action guitars too difficult to handle and, as a side effect, finger buzzing will be more common.
When comparing open notes, though, there is no denying that higher-action guitars fare much better than lower-action ones.