Action is the height of the strings from the fretboard on guitars, including classical guitars. Action has a direct impact on playability. If the action is too high, the guitar feels difficult to play. Your left hand has to press harder to hold down the strings. If the action is too low, the strings buzz against the frets.
When guitarists complain about high action, they are comparing the current guitar to another guitar they own or have owned which was easier to play. Or they are crossing over from the world of steel-string guitars that have a more favorable action.
Classical guitars have higher action than steel-string guitars. Nylon strings are under lower tension and vibrate in a wider arc, so they need that extra space to do their thing.
Given the greater amplitude of nylon string vibration (due to lower string tension), the action for a nylon string guitar will be slightly higher off the fretboard, although on the other hand, nylon strings are easier to press down than steel. Also, the spacing between the strings is wider on a classical guitar, partly to account for the greater amplitude.
If that’s the case, if it’s in the very nature of classical guitars to have a relatively higher action, then what do players mean when they say they are facing a high action problem? Shouldn’t they be expecting it?
The main issue is that the strings just feel tight and difficult to keep down. If your guitar’s action is too high, your fingers need to push the strings down with some extra effort. This makes it awkward to play and slows you down. Or a player may absolutely love the sound and find it generally easy to play on the lower frets, but going past the 5th fret or so feels strenuous.
Folks who face this problem also talk of the strings feeling “very stiff”. So there is such a thing as a high action issue even if we are talking about only classical guitars.
How high should classical guitar action be?
What is the correct action for a classical guitar? There seems to be an unofficial standard evolving on this. Action is measured as the distance between the frets and the strings. Specifically, the distance is measured at the 12th fret from its top to the bottom of a given string.
An action of 3mm at the first string (top E) between the string’s bottom and the top of the 12th fret is considered normal. And an action of 4mm at the sixth string (bottom E) is considered normal – with the strings in between having values between 3 mm and 4 mm progressively.
These figures may vary up or down slightly but no more than 0.5mm. A difference of 1 mm is generally considered advisable between the bass and trebles.
Some experts suggest taking another set of similar measurements at the first fret. The action numbers here will be really low: 0.8mm from bottom of 6th (low E) string to the first fret and 0.6mm from 1st (high E) to fret would be considered ‘normal’.
Older guitars – often from famous luthiers – have their 12th fret action numbers usually exceeding the above ‘normal’. Even many concert performers today prefer action numbers that overrun the ones above.
The “best” action will thus be different depending on the player and a few other variables we will shortly see. So let’s get this straight. Even if the numbers exceed the ones given above, for some players, there still may not be a problem at all.
As a related issue, there is such a thing as having too low an action too. Which in turn causes a different set of problems including string buzz. If you have the 3rd string buzzing, then check out my article How To Get Rid of G String Buzzes for helpful tips.
Is the action too high on my guitar?
It’s the kind of question only you can answer. Sure, you can use the rule-of-thumb measurement given above to check your guitar action at the 12th fret. If it roughly equals it, you have ‘normal’ action.
What if your measurement exceeds the ‘normal’? Will you become distressed? Not at all. You may still be holding a fantastic guitar in your hands!
Why is that?
Many classical players find out that a higher action lets them hit the strings harder without buzzing and permits louder volume playing. Those with an aggressive touch will enjoy a higher tension guitar than a lower one. As noted, many performers prefer higher tension guitars not only for the added volume but also more expressiveness. It’s a cleaner, more precise sound with more sustain.
Since the hands of a student are not as strong and trained as those of a professional player, you are more likely to find normal tension in student models rather than in more expensive guitars.
For the related cousin – the flamenco guitar – many top players go the other way. They look for a lower action for faster, easier playing. They don’t mind the string buzzing sound when they play hard. The buzz against the frets is a bit like an analog “distortion” and is very much part of the flamenco sound.
A low action, incidentally, would be around 3.5/2.5mm for 6th/1st strings.
How you perceive action is also affected by the tension of the strings. Higher the tension, the harder it is to depress the string and more difficult we perceive the action to be.
Depending on where you are on the classical guitar learning curve, the strength of your left hand, the sound you are going after and the amount of toil you are willing to expend to extract some music out of the instrument, you will decide how high a tension is good for you.
If high tension gets to be a problem, the good news is it is not too difficult to solve – in most cases.
How do you lower the action on a classical guitar?
It is not hard to adjust the action on a nylon strung guitar. It helps to know about the main things that matter. String action is determined by several factors –
- the angle at which the neck joins the body
- the height of the nut
- the height of the saddle in the bridge
- the height of the frets above the fretboard
To cut to the chase, the place where most would look to make a correction is the saddle more often than not. Adjustments are made at the saddle of the bridge. (Don’t use the adjustable neck rod for action adjustments. That is there for getting proper neck relief.)
The key is the height of the saddle in the bridge. Have a look at the saddle and check if it projects at least 2mm above the bridge. If it does, there is ample scope to lower the action.
The key to making any change needed for the action height at the 12th fret is understanding a simple numerical relationship it has with the saddle. If you need to bring the action down by 0.5 mm at the 12th fret, you will need to file down 1.0 mm at the saddle. Double the difference you want at the 12th fret and file away the saddle. Or give it to a luthier.
Sandpaper gives you better control, I am told (but I personally wouldn’t even go there. Give me a good luthier any time.) A quality 320 grit paper is known to work wonders apparently. 320 is fine enough for the finish on the bone while coarse enough for material removal. I’m just passing it on, folks. Sanding down anything isn’t my cup of tea.
If something like what this guy does with a sand block in this brief video interests you at all, you obviously know what you’re doing. Good luck to you!
Saddle filing video
In bringing the saddle as low as required, one factor to consider is if you can gain a bit of break angle by tying the strings differently. That is by using “bridge beads”. I have a full article on using bridge beads on the classical guitar in which I discuss things like the break angle and lots more.
Reducing saddle height is the most prevalent way of lowering the high action of your guitar to the acceptable level you want. Now that we know the popular solution, I will tell you about a much simpler solution that may get the job done. And, after that, a very extreme solution to get the job done.
Two more solutions to lower high action
Simple solution, first.
As noted earlier, how you perceive high action and playing difficulty sometimes comes from the tension of the strings used. It makes sense before you even go the saddle-filing way to consider changing to low tension strings. The difference can be dramatic.
Low tension strings make it easier to play. That’s the whole point of using them in a way. You might want to test out different brands, as they all have different meanings of the term “light” and “low tension”. I have a whole discussion of high tension and lesser tension strings in the article Which Tension Strings are Right For You? Take a look if you want to get to know which brands offer what features and how you go about choosing among them.
This may turn out to be a simple and surprising solution.
Or not. Some guitars, especially older ones that show signs of age and the neck isn’t any longer in perfect shape, can do with some extreme treatment (read expensive) to bring them back to life. And some guitars from the past are valuable enough to justify the repair job.
I’m talking about a re-fret job and some intensive work on the neck to bring the action to where it should be. Watch this luthier go to action (pardon the pun) on a valued guitar of his client’s. It is quite instructive to see the whole process and learn not just the steps in the process but also to understand deeply why you need a skillful luthier in the first place.
Some extreme work from a luthier
So there you have it. Even though the standard action of most well-built guitars should satisfy most players, there are some whose playing technique or personal preference will need a tailor-made action to suit them.
Hopefully, we have seen enough here to recommend that you get it done by a professional luthier or guitar technician. It’s not a big job and it should not be expensive (unless it’s that extreme treatment) but it should be done properly.