Whether you are a first-time guitar owner or a seasoned strummer, setting up an acoustic guitar neck can be a daunting challenge, especially when it comes to adjusting the truss rod! So, what needs to be done to set up your guitar neck?
To set up an acoustic guitar neck, first clean and polish the fretboard. Then you will need to check that the neck relief is correct and adjust the truss rod accordingly. You may also need to file or add a shim to the nut or saddle to get the action at a comfortable level for you to play.
Ok, that sounds pretty scary, right? It really does not need to be. All these steps are straightforward with the right knowledge and tools. In this article, we will be looking at everything you need to do to set up the neck of your acoustic guitar. Let us get started!
Related: new to this topic? Start with our complete guitar maintenance and cleaning guide.
How To Set Up an Acoustic Guitar Neck: Caring for Your Acoustic Guitar Neck Fretboard
This is not so much neck set-up as it is acoustic guitar neck maintenance, but it is a good idea to give the fretboard some care before you start onto the complicated things like truss rod adjustments. With the strings all taken off the guitar, give the fretboard a quick wipe down with a cloth to remove any dirt. If it is a new guitar you are setting up, this might be all you need to do. The fretboards of new guitars have often been recently polished and will not be very dirty.
If you are making some set-up adjustments on an old guitar, however, you will want to give the fretboard a deep clean. Over time, the dirt and oils on your fingers build up on the fretboard, and this can affect string life! If it is really stuck on, try using a bit of steel wool to remove the grime. Be careful to only move it along the grain of the wood to prevent scratching!
It is also a good idea to apply specialized fretboard oil like this D’addario Lemon Oil. This will prevent cracking and dryness, as well as helping to stop gunk from building up on the fretboard over time. The fretboard is the interface between your fingers and the neck of the guitar, so it is important to keep it in good condition! While you have the strings off already is a great time to do this since it prevents you from having to take them off specifically for cleaning.
What Is the Action On An Acoustic Guitar?
Since a lot of the set-up that needs to be done on an acoustic guitar neck relates to the action, it will be helpful to spend some time explaining what it is and how to tell if your guitar’s action is incorrect. In short, the action is simply the distance between the strings and the frets. If that distance is too high, it will be difficult to press down the strings far enough to produce a note, and this will slow down your playing and make it feel less comfortable.
However, if the action is too low, you will get a lot of ‘fret buzz,’ or you will not be able to play the notes at all. The playing style will affect how high or low you need the action to be. For someone who aggressively strums the strings, a higher action is probably better. That is because aggressive playing causes more vibration of the strings, leading to more fret buzz. Someone who very gently plays will be more comfortable with lower action and will not get fret buzz.
Intonation
Intonation refers to how in tune your guitar is at different points of the neck. If the action is too high, you might find that a note played on one part of a string is out of tune with the same note played on a different part of the neck. In other words, even if you have tuned the open strings to each other perfectly, the guitar might become more and more out of tune as you move further up the neck.
This is because if the action is too high, there is more distance between the fret and the string at the higher frets. More distance means you can press the string down further, creating extra tension, which can translate to an out of tune note. A small amount of relief is perfect since it means the action will be low at the high frets without causing fret buzz at the lower frets. Getting the right action for comfortable playing without affecting intonation is a delicate dance!
Checking the Truss Rod Alignment For An Acoustic Guitar
This is perhaps the scariest step involved in setting up a guitar neck since it requires extreme care not to do serious damage to the guitar (Related: how to fix a warped guitar neck). Most guitarists recommend going to a professional for truss rod adjustments for this reason, but you can do this at home if you are feeling adventurous and brave. This needs to be done first because later steps will be affected by the truss rod’s tension.
What Is the Truss Rod?
A truss rod is a steel rod that runs along the neck of the guitar. When you put strings on a guitar and tune them up, this puts a lot of tension on the neck and tries to force the neck to bend towards the front of the guitar. The truss rod aims to compensate for this tension by pulling the neck in the opposite direction. The truss rod applies tension to the neck to ensure that the tense strings do not cause the neck to bend so much that the guitar is unplayable.
Does My Guitar Have a Truss Rod?
The only acoustic guitars which are unlikely to have a truss rod are nylon-stringed classical guitars. That is because the nylon creates less tension to compensate for. A steel-stringed acoustic will almost always have an adjustable truss rod. You can check by looking for the adjustment nut. This will either be at the top of the neck at the headstock or the bottom of the neck beside the soundhole.
Do I Need To Adjust the Truss Rod For An Acoustic Guitar?
The best way to know if you need to adjust the truss rod is if the action feels really wrong! However, other factors affect the action, so adjusting the truss rod is not the end of the process. It can be tricky to know whether you need to adjust the truss rod and how far to adjust it if you do. Unfortunately, the process for checking how much you need to adjust it can also be quite tricky and complicated. In this section, we will be showing you how to measure this:
Relief and Backbowing
When the neck bends ‘forward’ as a result of the string tension, that is referred to as the ‘relief.’ All guitars should have some relief or else the action will be too low, but the relief will increase over time as the string tension pulls the neck forward. When you tighten the truss rod, you counteract the relief caused by the strings. Tighten it too far, however, and you will end up with a ‘back bow,’ which means the neck is bent too far the other way, resulting in too low action.
How to Measure the Relief
Ok, this is a very tricky bit, so we will spend quite a bit of time on this. In order to know whether you need to adjust the truss rod, you will need to know the relief. One clever way to do this is to simultaneously fret the 1st and 14th frets, then measure the distance between the top of the 8th fret and the bottom of the string at the 8th fret. If you have fewer than 3 hands, you can use a capo to fret the string at the 1st fret.
This is very hard to measure, but for a steel-string acoustic, the distance between the string and fret at the 8th fret with the 1st and 14th pressed down should be between 1/64th of an inch (0.396mm) and 1/32nd of an inch (0.793mm). That is a tiny measurement, and you will need a machinist ruler like this Stainless Steel Machinist Ruler/Rule Scale, which includes 64ths of an inch.
A much easier way, however, than measuring it precisely, is to use a business card. One business card is about 1/64th of an inch thick, and two business cards are about 1/32nd of an inch. In other words, with the 1st and 14th frets pressed down, you should be able to fit between one and two business cards between the top of the fret and the bottom of the string. If you do not have a business card, a credit card is almost exactly twice the thickness of a business card.
In essence, when you are pressing down the 1st and 14th frets, the string should be very nearly touching the 8th fret, but not quite! If the string is touching the fret, you will need to loosen the truss rod ever so slightly. If the gap between the fret and the string is bigger than 2 business cards (or 1 credit card), then you will need to tighten the truss rod ever so slightly.
Adjusting the Truss Rod On Your Acoustic Guitar
Now that we know how to tell whether the truss rod needs to be adjusted, it is time to look at how to do it. It is important to say right at the start that when you are adjusting the truss rod, you need to be extremely careful not to turn the nut too far. You should only turn the nut ¼ of a turn at a time! If you tighten it too much, you could end up doing some serious damage to the neck of the guitar.
The truss rod adjustment nut, called the ‘hex bolt,’ is normally located just inside the soundhole, on the side closer to the head of the guitar. Sometimes, however, it is located on the headstock of the guitar.
Turning the Hex Bolt
As mentioned above, which way you need to turn the hex bolt will depend on the neck relief, which is measured by fretting the 1st and 14th frets, then measuring the distance between the 8th fret and the string. If the gap is more than the thickness of 2 business cards, you will need to turn the hex bolt clockwise to tighten it. If you are standing at the bottom of the guitar looking towards the head, that means you turn the hex bolt to the right.