How to tell if a guitar needs to be adjusted

How to tell if a guitar needs to be adjusted

Although it might seem surprising, most guitars being used nowadays would benefit greatly from an adjustment.

Of course, time and normal use will contribute to the need for an adjustment once in a while. But, most of all, almost all new guitars sold are badly adjusted. I have had in my shop new guitars worth up to $3000 that hadn’t seen a single adjustment!

A guitar properly adjusted becomes much easier to play. And chances are it will sound more in tune. Many beginners who give up after trying to play for a few weeks would certainly have found learning more pleasant with a properly adjusted guitar.

Here then are a few small things you can check to find out if your guitar needs an adjustment.

The quality of sound and pitch

Sometimes, you can tell a guitar is not properly adjusted simply by listening to it. For instance, when strings buzz too easily, whether on open strings, at precise points, or all over the fretboard. If this is the case, the strings might be too low or the fret height uneven.

If the notes get more out of tune the higher you go up the neck (towards the soundhole), you can start looking for answers. It might be due to the saddle being positioned improperly (requiring much more work to correct than a simple adjustment), or simply by strings being too far away from the fretboard (something easily adjustable). Strings too high, besides making the guitar out of tune, will have the bad tendency to make chords harder to play, particularly barre chords. Who has never pestered while learning the F chord? If that guitar had been adjusted properly, it would most likely have made it easier to learn.

You can also tell there is problem of adjustment when the guitar gets out of tune too easily (i.e. if the guitar systematically gets out of tune after each piece you play). All too often, this problem is wrongly blamed on bad tuning machines. Usually, it is caused by string grooves in the nut being too narrow, preventing the strings from sliding freely. Still, it is normal to have to retune a guitar regularly, depending on its use, on variations in humidity and temperature.

It is also possible your guitar might benefit from an adjustment even if the problem can’t be heard. If you believe that is the case, here are some technical points to check.

The action

The first thing to check is how high the strings are from the fretboard. To be more precise, it is the height at the 12th fret, the distance between the top of the fret and the bottom of the string. This is commonly known as the action of the guitar.

6th String is Almost 3mm

In the picture, the action of the 6th string is almost 3 mm.

There are many reasons to modify the action of a guitar. First, the playing style will affect the desired action. The lower the action, the sooner the strings will buzz when you play louder. Players who prefer to fingerpick will be able to have a lower action than those using a pick. The type of guitar too will influence the action. For instance, a nylon-string guitar will not have the same action as a steel-string.

Here is a small table with the different heights to aim for, according to the guitar type.

Action at the 1st string Action at the 6th string
Steel-string guitars from 1.5 to 3mm from 2.5mm to 4mm
Nylon-string guitars from 2.5mm to 3.5mm from 3.5mm to 4.5mm
Electric guitars from 1.5mm to 2mm from 2mm to 2.5mm

These heights should only give you a general idea of the action prefered by most. You might very well prefer one that is different from those shown here.

The height of the strings at the nut

Very often, the strings are too high at the nut. As with the action when it is too high, chords will be very difficult to play, particularly near the nut. Normally, the strings at the nut should barely be higher than the height of a fret.

Strings Buzz if Too Low

An easy way to tell if the strings are too high at the nut is to use a capo at the first fret. If it makes the guitar much easier to play, it means they are too high. A guitar adjusted properly should be as easy to play with or without a capo.

A more technical way to check the height is to pinch the strings one by one at the 3rd fret and to check the clearance between the 1st fret and the string. It shouldn’t be more than the thickness of a sheet of paper. If the strings buzz when open, they might be too low.

The relief of the neck

Check the Relief

The neck of a guitar is never completely flat. The string tension will induce a slight curve, or relief. It is necessary, up to a point, to ease playing. The relief allows a low action, without too frequent buzzing.

When there is too much relief, the action will be too high or the fretboard will rise towards the sound hole. Too little relief and the strings will tend to buzz.

To check the relief of a neck, just use the following procedure:

  • Pinch the 6th string at the first fret
  • Simultaneously, pinch that same string at the 13th fret
  • Measure the clearance between the 6th fret and the string.

There should be just enough clearance for a piece of thick paper, like a business card. The picture above shows the procedure described to check the relief.

Worn frets

The last point to check, and most likely the easiest, is fret wear. There will be grooves on certain frets, exactly below the strings. These grooves are wear marks, caused by the friction of the strings. A guitar with worn frets will sound out of tune and buzz on certain frets.

Check the Relief

In most cases, leveling the frets will be enough (filing and recrowning). If the frets are too worn or have already been leveled a few times (making them too thin), it might be necessary to replace them.

You should now be able to check by yourself if your guitar is properly adjusted or not. I encourage you to do so. Bring your guitar to a luthier if you think it needs to be adjusted. Your life as a guitar player will be so much more pleasant if your guitar is well adjusted!

By Alain Moisan of Les Guitares Moisan