rct Posted May 27, 2014 Posted May 27, 2014 No. Intonation is placing the 12th fret, that is, where you stop the string at that place we call the 12th fret, exactly in the middle between the nut where the string stops and the bridge where the string stops. So if you just measure from one end to the other you are not accounting for finding the middle, just the length. Should be clear as concrete now. rct
rct Posted May 27, 2014 Posted May 27, 2014 Actually, those numbers are nominal. We can't possibly accurately measure where the string stops in the nut to where the string stops on the saddle, it's a fairly dynamic point that changes with temperature and with movement of string while playing. So a good tuner is still the best way to intonate your guitar. Or I'm getting the question all wrong. rct
Sitedrifter Posted May 27, 2014 Posted May 27, 2014 No, I think we're on track. I will not measure 'to force' a 24.75" length; I will do the 'find the middle' method and retain the 24.67". Thanks for the help, as always! I went down this path with all my Gibsons, not one measures 25.5" or 24.75" they all vary. My Taylor and Yamaha measure exactly 25.5" scale. I am looking at the new long scale (25.5") LP and I am sure it will run around 25" or so but it is will still be more comfortable then my current LP.
David Collins Posted May 27, 2014 Posted May 27, 2014 Short answer, Gibson does use a true 24.75" base scale length. Their fret spacing however (at least in Nashville and Kalamazoo post-1947, but not Bozeman) is based on the centuries-old "rule of 18" rather than the modern 12th root of two derivative 17.817. This means that when the math is done, a Gibson 24.75" base scale comes out with the equivalent string length of what would be a 24.57 relative scale by any other maker. For the long answer, here's an excerpt from a paper I wrote some years back. Though it may seem a basic and fundamental point of fretted instrument design, “scale length” has become (or perhaps always been) a rather ambiguous term in the field of fretted instruments. There are in fact several distinct definitions applied to the term by different companies and technicians, as well as some common usages which I hesitate to qualify as proper definitions. The Martin Guitar Company’s use of the term is a prime example of this*. At least for the purpose of this writing, I will clarify my own definitions of two distinct descriptions of scale length that are most commonly used. Base Scale Length: The base number from which the fret spacing is calculated. In other words, it is the original length from which the fret scale (i.e., rule, template) is laid out. Relative Scale Length: 2x the distance from the nut to the center of the 12th fret. This definition does not always directly determine or reflect the spacing of the frets relative to each other. Though this is probably less pure a definition of scale length than the former, it is generally considered the more useful of the two, and certainly more widely used. Its value lies both in its ease of calculation, as well as its ability to provide consistent comparisons between boards of different fret placement systems. Assuming all setup criteria remain constant between them, and intonation is conventionally adjusted to 0¢ offset at the 12th fret, the same relative scale length will result in the same end string length, even between boards of different fret spacing systems or nut compensation. *In efforts of disambiguation, at least one other common use of the term deserves to be mentioned. The Martin Guitar Company defines their “scale length” according to the open length of the high E string, including average compensation (of approximately .060”). This method of defining scale length as the total length of a string is likely carried over from non-fretted relatives such as the violin. On fretless instruments where there are no frets to govern the total string length, the string length of course will instead dictate the fingering positions. This makes defining scale length as the total string length both appropriate and necessary as a relative term for comparing these instruments. On fretted instruments however, I feel this usage suffers great inadequacies. Foremost is the fact that with a system of straight frets, each string will require a different amount of compensation, and end at a total open length different from others. This leaves the rather ambiguous choice of which string or point along the saddle one chooses to refer to. Martin uses the total high E string length today, but you will hear of others using the average among all strings, and still others choosing the low E. Furthermore, the end length with compensation will change relative to details such as setup or string choice, presenting us with the possibility of the same instrument being describable as several different scale lengths dependant on changes in these details. While it is unlikely we will see this usage of the term disappear, I feel it best reserved for use as a layman’s approximation. It carries little to no benefit in any technical discussion, and can serve simply to confuse when any need for accuracy is involved. I have personally encountered cases in which small builders have misplaced their bridge, where the fingerboard was sold as a “25.4” scale, and the saddle template labeled the same, but the two used incompatible definitions. For purpose of technical discussions therefore, I prefer to omit this usage entirely, and reserve the term “scale length” to either the “relative” or “base” definitions listed above. ..... If a board were slotted to the modern standard of 2^(1/12) spacing and the nut located accordingly with no compensation, the Base and Relative scale lengths would be identical. When a board is spaced to an alternate system such as the true rule of 18 however, the relative scale lengths would indeed be quite different, even though they began with the same base scale length. For example, if a spacing were to start from a 24.75” Base Scale Length, and use the true rule of 18, the 12th fret would not fall at the halfway point of 12.375” as it would using the 2^(1/12) rule. Rather, it would fall notably short at 12.285”, and in order to intonate properly at the 12th fret, the bridge position would need to be adjusted accordingly. The same 24.75” Base Scale Length is used in each scenario, yet the Relative Scale Length of the “rule of 18” board would end up at 24.57”, while a 2^(1/12) spaced board's relative scale would remain at 24.75”. This is in fact where much confusion occurs in the labeling of scale lengths on Gibson guitars, and demonstrates the need to distinguish the two definitions as independent. Of course if you're measuring to set intonation on an existing guitar, this is largely a non-issue. Everything you need to do here can be accomplished with a tuner, and there is typically no need to involve length measurements.
Kaiser Bill Posted May 27, 2014 Posted May 27, 2014 I would just hit the twelfth fret harmonic, and using a tuner...adjust your bridge saddle and you should be good to go. I first started doing this for nearly every guitar player in town when I got my first Peterson Strobe tuner back in '72. It never fails to please.
David Collins Posted May 28, 2014 Posted May 28, 2014 Best thing to do really is put the ruler away and forget about the numbers entirely. When laying out or building a new guitar the numbers are useful. Once you have strings on it though, everything you typically need is better read on a tuner than a scale. Dimensions become little more than an academic side note you can take of you want, after the intonation has be set by observing actual pitch.
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