Guitar Action Adjustment

Action Adjustment - Setting The String Height

Its All About The Feel

Measuring the string height at the 12th fret

Beyond the mechanics of the instrument, there is an aspect of tailoring that takes place when performing a setup. In our shop, the first step is to gather information about the clients playing style and what they desire out of the instrument. This is important in guiding us towards how to best adjust their guitar or bass in a manner that they will find comfortable. 

Through countless such interactions, we have found that guitarists occasionally harbor misperceptions about the perfect setup. Nowhere is this more apparent than as regards the guitars “action”

What is the Guitars "Action?"

The guitars “action” refers to the height of the strings in relation to the frets. If the action is too high, strings far away from the fretboard, the guitar can be difficult to play and may not intonate properly. If the action is too low, strings very close to the frets, the guitar may have an audible chattering or a muted buzz in certain positions as the strings vibrate against the frets. Depending on personal taste, guitarists strive to have their playing action fall somewhere in-between those two extremes. The “sweet spot” between these two extremes is as varied as the instrument and their owners.

How We Measure Instrument Action

We rely on a handful of key measurements to dial in the setup of a guitar or bass. We typically measure everything from pickup height, fretboard radius, string height at the first fret, etc. Among the measurements we rely on most heavily for measuring action are 12th fret string height and neck relief. Comparing the findings against benchmark measurements and manufacturers specifications gives a good frame of reference for a given instrument. 

To measure neck relief, with the guitar in the playing position, we first place a straight edge across the frets. We then insert a feeler gauge between the fret tops and the bottom of the straight edge, around the 7th-9th frets, to asses how much “relief” (forward bow) there is in the neck. In conjunction with measurements taken at the nut, this gives a fair assessment of how the instrument will feel in the lower register.

To measure the 12th fret string height, while holding the guitar in the playing position, we press down the highest string at the first fret and measure the distance between the fret top and the bottom of the string at the 12th fret using a ruler with 1/64″ graduations.  We then repeat this procedure for the lowest string.  Having already determined that the strings are properly radiuses to the fingerboard, this gives us a fairly reliable measurement of the action for the instruments upper register.

"As Low As Possible Without Buzzing"

When clients are asked how they like their action, the response is almost universal: “as low as possible without buzzing.” This phrase is ubiquitous and, unfortunately, almost completely useless to a guitar tech. To put a point on it: How low an action can go without buzzing depends on a combination of factors, some of which are simply beyond a guitar techs ability to control.   

There are certainly many tangible factors such as the style and quality of the instruments fretwork, the tuning, gauge and composition of strings, the way an instrument is strung, the pickup height, etc. that are all important, but there is an “x” factor here that most clients overlook…

The playing style and attack of the musician are the biggest variable in setting an instruments action. A player who strums aggressively, or picks close to the fingerboard rather than nearer to the bridge, will almost certainly require higher string height to avoid buzzing when compared to a player with a lighter “touch” and more precise picking control. Similarly players who use light strings usually need the action higher than they might with heavier. 

Last to consider is ones tolerance for string noise. Some players don’t mind an occasional sizzle; For example, just listen to a recording of an undisputed virtuoso like Tommy Emmanuel and you will almost certainly hear a fair amount of buzz and string noise; It doesn’t seem to bother him and it certainly doesn’t make me any less impressed by his playing! Still some other players have an uncanny ability to zero in on any offending sound and subconsciously go out of their way to pick in just such a way as to ensure that it will present itself. The more accurately that you articulate your preferences, the better chance we have of helping get you where you want to go!

Low String Action

There is no denying the benefits of a low action: easy bar chording and faster playing for quick runs or “sweep” picking are certainly the major ones. These are great benefits and can be crucial for some highly technical styles of playing. Low action can also be a big help to beginners, children, or people with arthritis. However, these attributes can be more advantageous for some than others, and very low action is not right for all players.

Even for a guitar that has good fretwork with level frets, very low action requires a very light picking hand in order to avoid any “fret chatter”. For those with a light touch, or playing with so much distortion that slight rattles would be inaudible, this is not a problem. However, if you like to dig in with your picking hand, or are extremely buzz-phobic, this might be a cause for concern. Another thing to consider with low action is that your instrument will have a much tighter tolerance for seasonal shifts due to humidity fluctuations.

Medium String Action

Players who prefer a more “medium” action may have to work comparatively harder to get the strings down to the fret, but in turn they experience notes with a fuller bloom and longer sustain.

Those who love to bend strings might also benefit from a more “medium” action. Many of you know that the fretboard of a guitar is not flat. It is curved, higher towards the center, in order to more comfortably fit our hand as we play. Though the degree of this curvature varies some, if the action is set very low to the fretboard, notes may buzz or “fret out” as they are bent. This happens because when bending the string you are actually forcing it into the contour of the fretboard. Some string benders say that a bit higher action helps them to “get underneath” the string as they bend too.

High String Action

After a certain point, too much string height moves out of the realm of “preference” and can become a barrier to proper functionality. Besides making the instrument uncomfortable to play, high action can cause intonation issues.  Briefly – Intonation is the instruments ability to play fretted notes in tune relative to one another. If the strings are too high off the fretboard, the string must be pressed further out of its original plane in order to fret a note; similar to the act of bending a fretted string, this raises the pitch and makes notes play “sharp” relative to the open string.  

Some Closing Thoughts About Your Guitars Action

The action being either “too high” or “too low” are among the more common complaints that bring clients into the guitar shop. While there are certainly extremes in either direction that are indisputable, within a range, string height is largely a matter of preference. What is right for one will inevitably be wrong for another. If you are unsure, it is worth trying both ways in order to figure out what works best for you. I hope that considering the above information will allow you to be a more informed player and help you to get the results you want out of your guitar.

About Guitar Repair Long Island

Guitar Repair Long Island is the area’s premier destination for fretted musical instrument care and maintenance. Led by owner/head technician Erik Salomon, the shop is dedicated to providing quick, honest, and reliable service. Our vast experience in all aspects of instrument repair ensures that we can help with whatever your needs are. Contact us with any questions or book your appointment today.

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