Is there a specific way to check the intonation on a fretless bass, i.e. adjusting the string lengths at the bridge, or does it simply not matter, as we're keeping in tune by ear anyhow?


6 Answers 6


I think it matters if you care about having consistent technique and intonation.

The reason is, correct intonation makes the strings in tune with each other as you move across the fingerboard in the exact same position. You want the octave on one string to be the same place on the fingerboard as octaves on all the other strings (on an imaginary fretline). The difference is that with a fretted bass, that point is fixed (ignoring neck adjustments, refretting, dressing, etc.). On a fretless, it doesn't matter where the imaginary fretline lies exactly, as long as the strings are in tune relative to each other.

The reality though, is that this is probably a finicky adjustment. I am just making this up now, but using something like a capo (because fingers are less precise because they are soft and fleshy) and first making sure it is perpendicular to the neck, would then let you adjust all of the intonations so they are correct for that position, e.g., first octave position.

  • Although, as there is no 'ideal' capo, you'd need to actually have a capo that compensated for the different thicknesses, tensions and height in order to really do this.
    – Doktor Mayhem
    Commented Sep 21, 2012 at 19:39
  • 3
    @DrMayhem I don't think so - it's really just about getting a good precise perpendicular. Basically, if you bar all 4 string with your index finger, it should be in tune, or if you play a harmonic on one string and then move down, you should hit the harmonic on the next string in the exact same place. While this is easy to do with octave harmonics, when you get into the higher harmonics you need really precise positioning to hit them exactly. To be honest I would never worry about this stuff, myself. Being purely academic here :)
    – RedFilter
    Commented Sep 21, 2012 at 19:56

You can make sure that you're in the ballpark using traditional intonation techniques. Play a 12th fret harmonic on each string, and compare that to a 12th fret "fretted" note. I say "fretted" because, well, there are none. You get the idea.

Use a tuner, and just ensure that you are in the ballpark when fretting right on the 12th fret line (if you have the line markers on your neck). If you don't have a marked neck, general ballpark in tune is fine.

You just want to ensure that things aren't off by a huge amount, so that you don't have to reposition your fingers in the fret as you ascend and descend the neck. In that case, you would be playing "right on the line" for the lower frets, but may have to sit back further in the fret as you ascend.

  • 1
    Thanks jp. What I actually did was use masking tape around 12th fret ( my basses have no fretlines),and mark on it where the '12th fret' was, as in harmonic.It's important, as , if '12th fret' is in a different place for each string, I'd be searching up or down for each separately, and with 5 of them, it might as well be right.
    – Tim
    Commented May 11, 2013 at 11:09

It really shouldn't matter, as you correctly state, because you adjust your finger position in order to hit the correct note.

In saying that, however, there is a reason you may wish to adjust intonation in certain circumstances. I haven't delved to deeply into this, but for a well set up instrument with a neck matched to particular resonant frequencies you could improve the frequency response by correctly adjusting string lengths. I think this is towards the high effort end of things though, and not sure of the value in normal use.


To some extent, muscle memory will come into play and your finger, whether there is a fret there or not, will "know" where to go.

If the instrument isn't properly adjusted like normal for intonation then you'll have you wander more for the correct pitch.

A half hour with a strobe tuner (meaning, something accurate enough to warrant the time with it) and adjustment at the bridge (dependent on model and manufacturer) will allow you to correctly set it. Just because frets aren't there doesn't insist that intonation adjustment is optional. Especially with vertical fret markers.

Does this fretless bass have fret markers at all on the fingerboard? If so, they can be a visual guide, and therefore would require a good intonation setup to be worth anything visually to you.

  • Para 1 and 2 agreed, which spawned the question.However, if the intonation is out,the notes won't be accurate. Markers are there , no fret lines.Thus, it would be beneficial to have correct intonation.
    – Tim
    Commented May 12, 2013 at 21:06

Short answer: Doesn't matter so long as intonation is uniform between strings and you aren't looking at fret markers.

Long answer: Intonation, tuning, and action go hand in hand. On top of that, nut end action will play a larger role on a fretless as you will likely have higher action there. Obviously your span decreases anyhow as you approach higher notes, but it would be nice to maintain intervals between strings at least.

It's all about compromises which suit style. Personally I tune my fretless bass and fretless 6-string acoustic at the third fret because I don't employ open strings much anyhow, and value consistency along the neck more.

Also some intonation is intentionally altered so you have different intervals an octave higher. Without frets, you have the spontaneous choice to create or negate that intonation behavior though.

Fretless calls for much higher action to prevent fret-buzz, and because imperfections in neck curvature stand out much more - otherwise you also need to be more careful about perpendicular plucking/strumming to not accidentally slap.

While the conventional open to 12th fret comparison is still useful, you may prefer a 3rd to 15th or 5th/17th fret comparison, which require some fancy math and measurement if you don't already at least have fret marker lines. In this way you rule out some action influence. Again, this depends on your style, neck or nut, opens or not.

Ear and muscle will adapt, but, as with how to logarithmically reduce your finger span, it will be easier on your subconscious if that is at least smooth and consistent as you graduate up/down and string to string.

So long as it's consistent between strings, you could really have any intonation. All it does is displace where your fret markers are, to essentially give your guitar a different scale length, but ultimately it's all brain hardwired smooth logarithmic transition anyhow. What difference if the halfway mark, the first octave, is 16.8 or 17.2 inches? This is different on every guitar anyway, so unless you can't adapt to playing other guitars, it's not really an issue.

  • The difference it makes, which is where the question comes in, is that each sting will have a different optimum open speaking length, just like a guitar, which is adjusted with the saddles. With that done, I can hit an accurate, say, 10th 'fret' each time. If the intonation is not correct for each string, it may be that the E string at fret 10 (D) position is not going to give an accurate G at fret 10 on the A string. Might as well be right. Your supposition of 16.8 or 17.2" is arbitrary. There is ONLY one place where the '12th fret' CAN be.
    – Tim
    Commented Apr 22, 2015 at 12:32
  • The 12th fret will be wherever half the string is, after factoring in saddle height. The 11th fret will be 1.05.. x that length. You're missing my point that if you are fretless, it no longer matters exactly where that 12th or 11th fret (which would change due to longer scale length or severe action), because your fingers would learn to slide instead to the new actual fret location for that string. Also these new locations would still be logarithmically proportional. A new overall scale length would be easy to adapt to. Different scale lengths between strings however would not. Commented Apr 24, 2015 at 3:39
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    We're saying the same thing I think. Whether 12th fret, octave, half-string, double frequency, ends up at 16.8" or 17.2", if it's not the same for each string, each string will have to have it's own proportional scale for fret locating. It would be nice as you say that 10th fret D and 10th fret G are both found at the same neck position. However one loses that with fanned frets anyhow. We can adapt. Commented Apr 24, 2015 at 3:43

It would seem to me that by moving the saddles, effectively it's going to move the 'frets'. As in where one presses the string down to produce an in-tune note. Pretty important, as comparing to a fretted bass, where there's several millimetres of leeway, the same note being produced because of the fretwire, not where on the fret the finger is pressed down (within reason!). Some basses seem to put the markers where they would normally be - in the centre of the 'frets', whereas others seem to put them where the strings need to be pressed. So, maybe, moving the saddles will change this, if there's enough adjustment, and it will put, say, 12th 'fret' where you want. It's of great importance to me to be able to 'fret' a note spot on in tune, and I want the other strings to also be in tune in exactly the same place on the neck.

  • Interesting question, but I can't help thinking the "does it matter" part comes down to personal opinion/preference. As a violinist first and a guitarist second, the violinist in me says, if you've freed yourself from the shackles(!) of frets it's because you want more control over micro-intonation. If you have that control, you can adapt on the fly and deal with any minor intonation problems inherent in the instrument itself.
    – Bacs
    Commented Nov 6, 2015 at 13:28
  • @Bacs - it's not for microtonal stuff, it's for the different sound a fretless gives. Also the vibrato sounds very different - more like that in the violin family. And I need to be able to pitch a note spot on with no reference apart from the fret markers (bit of a misnomer there!). Once they tell me exactly where the fret would be, therefore where to press, I'm happy. Imagine first playing a violin with markers like fretwire then moving on to a proper one, that's the transition.
    – Tim
    Commented Nov 6, 2015 at 13:45

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