Guitar Tuning And Intonation Problems: How Can I Fix This?

Your guitar does not sound in tune and you can’t get it in tune- what’s going on?

New strings aren’t stretched and won’t hold their tune
Machine heads are poor quality and slip
String action is too high
Bridge needs adjusting
Frets are incorrectly installed
Neck angle needs adjusting
Your playing style is causing the problem

Tuning Problems On A Cigar Box Guitar And Their Remedies

New Strings Won’t Stay In Tune

When you install new strings on your cigar box guitar they will take a while to settle in. This means that your guitar strings will go out of tune more quickly when they are brand new.

To help with this, pull each string away slightly from the body of the guitar so that the string is stretched a little. I’m not talking about trying to pull it too far. Just pull enough to get it slightly out of tune. If you pull too hard you may snap a thin string so go steady.

Then retune the guitar and play for a bit. You can repeat this a couple of times for the first day or two of the new strings. You will be accelerating their settling in period. Metal strings tend to settle a bit quicker than nylon strings.

Machine Heads Or Tuning Pegs Slip

If the tension on a guitar string is causing a machine head to turn on its own, there is little you can do but replace the machine head. Poor quality gearing will not hold a string at the correct tension so the string will go out of tune.

However if the string is slipping off the machine head you need to anchor it better onto the machine head. Hopefully you haven’t cut the string too short. Not having enough string wrapped around the machine head may cause it to slip.

Remove the string from the machine head and poke the end of the string through the hole in the machine head. (Some people prefer to wrap the string around the shaft a couple of times before putting it through the hole.)

Holding your finger over the string, wind slowly ensuring that the string is not slipping out of position.

Unfortunately if it keeps slipping you have probably cut the string too short and will need to replace it.

I have written a post here about changing the strings if you want a bit more detail.

Neither Of These Help-What Now?

Intonation is the relationship between the different notes on an instrument. An instrument with good intonation is in tune with itself. This is not the same as an instrument being in tune with other instruments. It’s not a tuning issue; it’s a set-up issue.

Since the cigar box guitar is a hand-built instrument, there is a likelihood that when you first play the instrument you have just built that it does not play in tune with itself.

I have had this happen to me and it’s really annoying. I had spent hours getting the instrument ready, sawing and sanding and fitting and yet the cigar box guitar sounded awful.

It’s different than having a guitar that’s not in tune. You can remedy that by turning the machine heads or tuning pegs to get each string in tune.

If a cigar box guitar is in tune, playing the same note on a different string on a different fret sounds right. The two notes are in tune. For instance, if you fret the bottom lowest string at the 7th fret and then play the open middle string, they should be the same note if the guitar is in tune.

If you play a certain note on one string and try to replicate it on another and the notes are different, the guitar is out of tune.

It’s a whole other problem if the note interval that you expect between different frets does not sound correct. That’s an intonation problem.

Intonation Problems And How To Fix Them

Check If The String Action Is Too High

If your action is high and you are not intending to play with a slide, fretting will cause the note to be out of tune because you are bending the string too far.

To measure the string action:

measure between the top of the fret and the bottom of the string
use a string height ruler or a standard ruler with the measurement starting right from the edge of the ruler
measure at the 12th fret

For a cigar box guitar that you want to play without a slide, aim for a distance between the top of the fret and the bottom of the strings of about 1.8-2.6mm (4/64 inches – 6/64 inches) at the 12th fret. However the precise string action you choose is really down to personal preference and will depend on your playing style.

You want the action to be low enough so that when you press down a string it plays the note in tune. If the action is too high, the string will sound out of tune because you are effectively bending the note out of tune.

As I’ve said, to some extent an ideal action depends on your playing style. Low action for someone playing with a light hand will make it easier to play with less intonation problems.

However someone pressing down on the frets a bit harder may find that they get a lot of fret buzz. They will benefit from a higher action, but not so high to cause intonation problems. It’s a question of balance.

If you are playing a fretted guitar with a slide, the action needs to be a bit higher so that you don’t get fret buzz when you use the slide. If you are playing slide with an unfretted instrument, the action will not need to be so high as there are no frets to buzz.

Lowering The String Action On Your Cigar Box Guitar

Lower the bridge or saddle
Lower the nut
Alter the back angle

You can try lowering the bridge and the nut slightly to see if this helps. The trouble is that this then can cause fret buzz, especially if your frets are not level, so you may need to spend a bit of time lowering the offending frets.

You can remove individual fret wires and cut the notch slightly deeper but make sure that you don’t make the notch too wide or the fret wire will move. You can either fill the notch slightly with fine sawdust and glue or add a bit of superglue to hold a loose fret wire. Alternatively sand back the fret wire whilst it is still installed.

An adjustable metal saddle like the ones used on electric guitars can be used to adjust each string individually. Although these can seem a bit fiddly they are easier to deal with the action height than a standard bridge and saddle.

On a standard bridge and saddle, any adjustments need to be done very gradually. You can’t easily add back height once it is gone. You will need to add shims ( thin pieces of wood) to build up the height again. If you really mess it up, you will need to buy new parts.

How To Lower The Bridge On Your Guitar

Work out how much height you want to remove and draw a line with a pencil or marker on the bottom of the bridge. You want to avoid any adjustments to the top of the bridge as this will mean you need to cut the string slots again.

File or sand some of the depth away, making sure you keep parallel to the line you have drawn. ( Wear a mask when you are sanding plastic or bone)

Reinsert the bridge and check the height of the strings again.

Repeat this process, periodically checking the string height until you get the desired string action. This is a time consuming process and a bit annoying but it’s one of those things that just has to be done slow and steady.

Alter The Back Angle On Your Guitar

On a standard 6 string guitar, problems with string height can be addressed by altering the truss rod. A truss rod is a piece of metal ( or sometimes carbon) that alters the angle of the neck slightly in relation to the body of the guitar. Imagine the guitar laying down on a flat surface. The truss rod can lift the neck away from the surface or lower it down towards the surface.

However on a Cigar Box Guitar without a truss rod, we need to physically alter the neck angle by reinstalling it.

The back angle on a guitar is not the same as the break angle:

The back angle is the angle that the neck leans back away from the guitar body.
The break angle at the nut is the angle that the strings make as they pass from the nut to the headstock
The break angle at the bridge is the angle that the strings make as they pass from the bridge to the tailpiece

If you have built without a back angle or with a very low back angle on the neck, this can sometimes cause the action to be too high. If you haven’t glued the neck in ( I recommend that you use screws rather than glue) then you could try altering the angle of the neck to see if this helps to get the action lower without causing fret buzz.

Pros And Cons Of A Back Angle When Building A Cigar Box Guitar

Whether to install a back angle or not is again a matter of choice. It can help with getting a lower action, but it’s not the only way. Here is a table of pros and cons:

	with back angle	without back angle	best choice on this point	reason
ease of building	harder	easier	without back angle	easier
string height at 12th fret	can get lower action with a higher bridge	action is determined mostly by bridge height	either	personal preference
string height near bridge	higher	lower	with back angle	strumming doesn’t hit box so much
break angle at bridge	since bridge is higher, the break angle is enough to stop strings slipping or cutting into box	bridge is generally lower, so a floating bridge can have problems with strings slipping or cutting into box	either	floating bridge may benefit from a back angle

There is a really helpful video I’d like to recommend you watch.

Chicken Bone John explains this really well in his neck angle or no neck angle video on YouTube which includes diagrams: https://www.youtube.com/watch?v=Bb2YnBoZZDI

Adjust The Position Of The Bridge

A Cigar Box Guitar often has a floating bridge. This means that the bridge is not glued in place and is held in position by the string tension. It’s a good idea to mark the position of your bridge before you remove the strings since the bridge can move when the strings are changed and this will cause intonation problems.

A 3 string guitar with a floating bridge allows some fine adjustment similar to that found on an adjustable bridge. This is because you can lengthen or shorten the strings individually:

You can use this slight angling of the bridge to get each string intonated. This means that each string sounds at the right pitch when it is fretted. If it is slightly flat you need to shorten the string. If it is slightly sharp you need to lengthen the string.

Although a fret calculator will tell you the relative fret positions for a given scale length and you need to measure frets accurately, the actual length of each string might need to be adjusted VERY slightly. This is partly due to the fact that the strings are different thicknesses.

The bass string often needs to be very slightly longer than the top string. The difference can be barely visible but this tiny adjustment will make your guitar sound better.

The thicker bass string needs to be slightly longer than the thin top string so that both can be really in tune with each other all the way up the fretboard. This means that often the top of the bridge is angled back slightly ( top diagram in image above)

This adjustment can be made when your guitar is being accurately set up. (see section below)

Replace Incorrectly Placed Frets

If the frets are in the wrong positions along the neck because they are not measured accurately, the only way of fixing this is to remove the frets. You can either sand down the whole fretboard and re-insert all of them or replace just a couple.

Neither of these options are a fun job at all. So the key thing is, when measuring for the frets, take your time.

Always measure each fret distance from the nut. If you measure from fret to fret, small errors get compounded and your higher frets could end up being out of position.

If you just have one or two frets to replace you can fill the fret slots with very fine sawdust mixed with glue. Once the glue has dried you can sand the fretboard flat again. Then measure accurately and recut the frets with a fine saw blade.

Be as accurate as you possibly can both in marking them and cutting frets. Make sure they are perpendicular to the edged of the fretboard and aren’t wonky.

Setting Up A Cigar Box Guitar You Are Building

Setting up a guitar to suit you may take a bit of time, but when you get it right you will have an instrument that’s much easier to play. If you have built your guitar these are the things you need to look out for:

Is the neck straight?
Are the frets level?
Are the frets installed accurately?
Are the break angles enough to stop the strings slipping? ( You can use eyelet screws to guide strings on the headstock)
Is the bridge break angle high enough so that the strings do not cut into the box as they pass into the tailpiece?
Do the strings sit in the slots in the nut and bridge so that they are secure but without being so low that they do not ring out properly?
Is the action high enough to stop fret buzz, but low enough to play in tune with itself?
Do you need to alter the action by altering the bridge height or back angle?
Does the bridge need to be angled slightly?

A Word About Truss Rods

There is generally no truss rod on a cigar box guitar which is one of the things a standard guitar uses to help with intonation problems.

There is a way of adjusting the neck to give the effect of a truss rod which involves an adjustable screw holding the neck inside the box, but this only works for necks which do not stick out of the bottom of the box ( see the Chicken Bone John video I’ve linked to above)

Setting Up A Guitar You Have Bought

You can make the adjustments yourself or ask the maker or a guitar shop to set the instrument up for you. For a cigar box guitar you will need to find someone who knows about setting these up.

Be very careful of any adjustments you make if you are not really sure what you are doing because you could end up with an unplayable instrument or needing to replace parts.

How Playing Style Affects Intonation

When you fret a note you need to press straight down to get the pitch of note required. If you move the string to the side as you fret, this is called bending the note. It lowers the pitch ( and then raises it when you return to the center)

Now bending the note is a great way to add interest to music and certain advanced styles encourage bending of the notes You should be sure that you only use this technique when you mean to.

In general playing, to play in tune make sure the string is not being bent sideways.