A minority of nylon string guitar builders slant the saddle a little bit with the high E string about 1mm back and the low E about 2.25mm. For compensation, a guitar's bass strings need more length than the treble strings. So, assuming we have selected the appropriate scale length for the instrument we are building, we now have to evaluate a few other elements to determine how to add compensation to the saddle and thus properly intonate the instrument (we’ll cover nut compensation separately). Both (fretting templates, fret scale spreadsheets) are available from LMI. Luthier Kevin Ryan says this is “inherent inharmonicity” and explains the concept concisely in this passage from his website (www.ryanguitars.com): “…the fundamental of a string produces a tone along with, say, the 1st partial of that string (harmonic at the 12th fret). Tuning up! Compensation, therefore, flattens the note. If 12 th fret intonation for a string is flat then you'll need to move the point where the string actually contacts the saddle back towards the nut a little. If the note is flat or sharp, move the wire toward or away from the nut until the note and the harmonic are perfectly in tune. The answer lies in the physical properties of a vibrating string. Is a compensated saddle a must, and a necessary part of a setup? Then fret and pluck the designated string. Similarly, thicker strings will require more compensation. Similarly, the action at the nut (that is, between the nut and the first fret) will have a bearing on the compensation required at the nut. When I glue the bridge to the soundboard, I measure the distance from the middle of the 12th fret to the front edge (sound hole side) of the saddle slot in the bridge, ensuring that this distance is 327.0mm (for a 650mm scale length guitar). Most new Martins saddle are "generically" compensated, which is not alway perfect for every guitar. The position of a guitar’s frets, nut and saddle are all determined by what is called the scale length. We will attempt to cut a path through this material that will be accessible to the beginning luthier or to those who are beginning to work on (or just understand) their instruments. What is ‘scale length’? However, for the great majority of luthiers, it is simply a matter of moving the nut .012 to .014 closer to the saddle. It’s a similar situation if you double the length of a vibrating column of air (i.e. Keep in mind also that the angle of the string over the nut, and the degree to which a string moves at an angle from the nut to the tuning post, will increase tension in the string. An Unofficial forum for those who love Martin instruments - Founded by Steve Stallings. When we “jump” from the wound G string to the unwound B string, the relative mass of the B string is greater and therefore the string requires a little extra compensation (the jump goes between the wound D and unwound G on most electrics). This is Inherent Inharmonicity.”. Two, the thicker a string is, the stiffer it is (more tension). For example, a guitar tuned with a dropped D tuning, or the popular DADGAD tuning, does not usually require extra compensation, but if a player tunes the 1st string down to C or B, more compensation is needed. Slide a small wire (a piece of .010 steel string will work) between the tuned string and the saddle. It is now a common practice to compensate the nut by moving the breakaway point of the nut (which should be at the very edge) closer to the saddle a short distance. Play the note at the 12th fret. The proportion of stiffness to diameter in a half-section of a string is greater than the proportion in the whole string. Why? Why is a guitar’s saddle slanted? The same problem that is encountered higher up the neck, also occurs on the nut end of … Copyright this business. How does the scale length affect the guitar’s tone? Pluck the same 12th fret harmonic of the D then tune the B (fretted at the 3rd fret) to this harmonic. I have always believed that a guitar that plays in tune sounds better. I put a compensated bone saddle in my 00028VS when I couldn't get past the intonation problems playing up the neck (when I actually dare to venture up there), but never felt the need to do the same with my other two guitars. Tuning Notes: If it is sharp then you'll have to move the contact point away from the nut. 7975 Cameron Drive, Bldg. I now push the string aside, and file a small angle on the front edge of the saddle, exactly where the particular string breaks over the saddle, thereby moving the break point on the saddle away from the sound hole, and lengthening the string vibration length. Then play the harmonic at the 12th fret. The only compensated bridges you normally see on modern nylon stringed instruments are the electric and acoustic/electric ones -- back to Leo's observation that it is more important when amplification is being used. The problem stems from the fact that the strings have different thicknesses, and therefore do not stretch the same amount over a given scale length. The last four Martins I bought came with uncompensated saddles... but they are all 12 fret slotheads. WRC & Padauk Short Scale 604mm Classical 6-string, Torres 604mm Birdseye Maple & European Spruce, Antonio de Torres Replica - Birdseye Maple & Euro Spruce, Concert Level Cocobolo & Lutz Spruce Classical, Master Grade European Spruce Classical Guitar. Why do some guitars play more in tune than others? In the end, there is no substitute for experience. It should be mentioned that a good number of luthiers and repair people make their instruments as many of the factories do –without individually compensated strings. Two basic facts about strings bear on playability: One, the longer a string is (i.e. Intonation correction should be made at the saddle - not to make the 12th fret note in tune with the open string , but to make, as much as possible, all of the fretted notes in tune with each other . It’s important to recognize that tone begins with the string! it is necessary to eschew these formulas and fine tune the compensation for each string individually. 2. Since it is impractical to have a different saddle for every string on a classical guitar, the saddle needs to be altered to suit every string, if proper compensation is to be obtained. Mark a pinpoint on those two points then draw a line between the points. It oscillates slightly faster– i.e., sharper. Thanks for your answers. This is because of uneven stretching of the string and the subsequent erratic vibration patterns. Nut compensation also helps minimize the difference between notes played near the nut (which tend to be a bit sharp) and those between the 4th and 12th fret, which can run a little flat. In other words, the distance between the zero fret slot and the 1st fret slot is now shorter by exactly half the width of the slot, or 0.30mm (0.012”), the slot being 0.60mm (0.024”) wide. As we mentioned above, there can be subtle differences in intonation at different positions on the neck. Leo Fender claimed that his guitars were the first with truly accurate fret placement. My generation, and many generations before us, didn't even know what they were (they didn't exist!). Guitarists in particular often bend strings for pitch inflection. Our Phones are staffed: Compensation here is defined as lengthening the individual string length beyond the scale length. For example, most of us are familiar with the experience of tuning a guitar up so that an open chord sounds good – just to find that a barre chord up the neck sounds “off”. The shorter the scale length the more compensation is needed. It is not uncommon for classical builders to include some extra compensation for the G string. My ear's fairly discriminating.......and I do okay without one, on my guitar. I then remove another 0.50mm (0.020") from the end of the fingerboard. There can also be differences between open, fretted and harmonic tones. On a twelve string it is important that the bottom of the strings be level for the various courses (pairs of strings in octaves) to intonate correctly. Not an easy task! This difference between bass and treble compensation is why steel-string guitar saddles are installed at an angle. 7. As mentioned above, even the most expertly intonated guitar will not play perfectly in tune. Since it is impractical to have a different saddle for every string on a classical guitar, the saddle needs to be altered to suit every string, if proper compensation is to be obtained. Also, note that you will need to take the staggered string gauges on a 12 string into account when compensating the saddle. Playability Of course, electric guitar makers have it made when it comes to individually compensating the strings as many electrics have an individual, adjustable saddle for each string. Says Doolin, “The fact is, intonation is part of the expressive palette of most instruments. Unless one has the ears of a bat, the amount of correction most compensated acoustic bridge saddles offer (about 1-4 cents at best...100 being a semi-tone) can best be described as neglible. These articles help explain how the design of stringed fretted instruments presents inherent “problems” that the luthier (and to some degree, the musician) must work around and show that no instrument made with straight frets will play 100% in tune (according to a sensitive electronic tuner).