Posted on August 1, 2022March 5, 2024 by Dale Phillips Questions: String Tension and Purity of Tone Questions: String Tension and Purity of Tone by Alan Carruth Originally published in American Lutherie #99, 2009 See also, Questions: String Tension and Pure Tone by R.M. Mottola Alan Carruth from Newport, New Hampshire writes in response to Pat Bowen’s question in AL#98 about the relationship between string tension and purity of tone: While there is some truth in the equation higher tension=purer tone, it is, as the editor said, not as simple as that. A lot depends on how you get the higher tension. When you pluck a string, it vibrates at a set of different, but related, frequencies. For ideal strings, the kind that you only find in physics books, these frequencies form a harmonic series; each one is an exact whole-number multiple of the lowest (or fundamental) pitch that the string makes. Real strings don’t do this, and that affects the way they sound. Become A Member to Continue Reading This Article This article is part of our premium web content offered to Guild members. To view this and other web articles, join the Guild of American Luthiers. Members also receive 4 annual issues of American Lutherie and get discounts on products. For details, visit the membership page. If you are already a member, login for access or contact us to setup your account.
Posted on August 11, 2021March 5, 2024 by Dale Phillips The Anti-Murphy Concert The Anti-Murphy Concert by Alan Carruth Originally published in American Lutherie #39, 1994 I recently had the privilege of attending a somewhat unusual concert by the Tokyo String Quartet, with some acoustics experiments thrown in. Or maybe it was a physics lecture with live accompaniment? And then there was the quiz show part... I guess I’d better explain. The whole thing seems to have started with the coming together of a number of good ideas. One of the first was a plan by the Acoustical Society of America to produce an educational video on acoustics for grades K–12. This, of course, would require money to do, and the suggestion was made that a benefit concert be held. The members of the Tokyo String Quartet were contacted, and graciously consented. So far, so simple. But remember, we’re dealing with acousticians here. Why not use the opportunity to do a little research? For one thing, while the acoustics of empty halls are reasonably well understood, nobody is really sure what happens when you put in the audience. Since the object of most concert promoters is to have as large an audience as possible, and nobody likes to listen to music in an acoustically lousy hall, it seemed like a good subject for an experiment. And how about that violin thing; you know old vs. new and all? And while we’re at it... Become A Member to Continue Reading This Article This article is part of our premium web content offered to Guild members. To view this and other web articles, join the Guild of American Luthiers. Members also receive 4 annual issues of American Lutherie and get discounts on products. For details, visit the membership page. If you are already a member, login for access or contact us to setup your account.
Posted on April 12, 2021March 6, 2024 by Dale Phillips Free Plate Tuning, Part One: Theory Free Plate Tuning, Part One: Theory by Alan Carruth Originally published in American Lutherie #28, 1991 and Big Red Book of American Lutherie Volume 3, 2004 See also, Free Plate Tuning, Part Two: Violins by Alan Carruth Free Plate Tuning, Part Three: Guitars by Alan Carruth I started learning free plate tuning on violins and violas more than ten years ago from Carleen Hutchins. For those who have not had the pleasure of her acquaintance, Carleen is one of the founders of the Catgut Acoustical Society and its permanent secretary. She is an able scientist, a great teacher, a fine luthier, and a self-confessed mediocre violist. While working with physicist Frederick Saunders almost thirty years ago she helped rediscover and update the old Chladni method of visualizing the vibrations of plates. Her subsequent research, using Chladni patterns as a window into the differences between good and poor violins earned her a silver medal from the Acoustical Society of America. Violin makers have traditionally used some variant of “tap tone” tuning to guide them in working out the final graduations of the top and back plates. Although the technique seems simple and organic on the face of it, it is in fact very complex. It takes a long time, as well as a good ear and a lot of talent, to learn to tune plates by tap tone. Even those who are good at it don’t always succeed. Felix Savart, back in the 19th century, tried to adapt Chladni’s method to research on violin acoustics, but the technology wasn’t there. Now we have the means, and as we gain more understanding of how the instruments work, we also gain more control over the sound. And it doesn’t only work on violins. Fred Dickens, Graham Caldersmith, and Gila Eban have all done major work in applying the principles of violin acoustics to guitar construction. Of course, there are differences and it takes time and effort to sort them out, but physics is physics, or, as a friend of mine said, “it all comes down to F=mA in the end.” I have found these techniques to be useful, and sharing useful techniques is what the Guild is all about. Become A Member to Continue Reading This Article This article is part of our premium web content offered to Guild members. To view this and other web articles, join the Guild of American Luthiers. Members also receive 4 annual issues of American Lutherie and get discounts on products. For details, visit the membership page. If you are already a member, login for access or contact us to setup your account.
Posted on May 4, 2020March 6, 2024 by Dale Phillips Free Plate Tuning, Part Two: Violins Free Plate Tuning, Part Two: Violins by Alan Carruth Originally published in American Lutherie #29, 1992 and Big Red Book of American Lutherie Volume Three, 2004 See also, Free Plate Tuning, Part One: Theory by Alan Carruth Free Plate Tuning, Part Three: Guitars by Alan Carruth Before I get into plate tuning proper I’d like to digress a bit and discuss the rationale behind the process, and a couple of other things I find it useful to keep in mind while I’m working. And I can’t think of a better way to begin than by telling you about one of my more elaborate experiments. Fig. 15 gives the relevant information on my fourth and fifth violins. The idea was to check out the influence of asymmetric back graduations by building a pair of closely-matched fiddles with that as the only variable. The one-piece backs were cut from the same plank of bird’s-eye maple and the tops were cut from a red spruce 4×6 that I took out of the wall of my house when I put in a new chimney. The molds were routed using a template. Archings were checked for height at over two dozen points on each plate and were held to .2MM. Graduation, weight, and frequency data is as shown. The delta f mentioned is the frequency drop obtained when a 5G weight was stuck to the plate in an active area of the given mode. Fittings and so on were matched as closely as possible, and the two bridges were cut back to back from the same piece of maple. Become A Member to Continue Reading This Article This article is part of our premium web content offered to Guild members. To view this and other web articles, join the Guild of American Luthiers. Members also receive 4 annual issues of American Lutherie and get discounts on products. For details, visit the membership page. If you are already a member, login for access or contact us to setup your account.
Posted on March 2, 2020March 7, 2024 by Dale Phillips Free Plate Tuning, Part Three: Guitars Free Plate Tuning, Part Three: Guitars by Alan Carruth Originally published in American Lutherie #30, 1992 and Big Red Book of American Lutherie Volume Three, 2004 See also, Free Plate Tuning, Part One: Theory by Alan Carruth Free Plate Tuning, Part Two: Violins by Alan Carruth The guitar is somewhat simpler acoustically than the violin, and perhaps more limited. As a result it has evolved into a number of more or less specialized forms to suit different musical uses. It is difficult to imagine a guitar that could “do it all” the way a good violin can. Rather, each guitar seems to have a “center,” a sound that is characteristic of it that suits it for a particular style or player. Good guitars do have a wide dynamic and timbral range, but they always retain their characteristic sound. As I see it, a good part of the art in this game is deciding where you want the “center” to be, or, alternatively, how to get the “center” you want out of a given shape or set of wood. And then you want to have a broad dynamic and expressive range, good balance, and clarity or resolution; the ability to distinguish things like inner lines. No amount of acoustic science is going to tell you what priority to put on the different characteristics of the sound, nor whether you have succeeded in the end. But if you know what you’re doing, an oscillator and a jar of glitter can help you get the sound you want. One of the main simplifying factors between the guitar and the violin is the lack of a soundpost in the guitar. This allows the top and the back to be more independent; in acoustic terms they are not so tightly coupled and can act out of phase. Become A Member to Continue Reading This Article This article is part of our premium web content offered to Guild members. To view this and other web articles, join the Guild of American Luthiers. Members also receive 4 annual issues of American Lutherie and get discounts on products. For details, visit the membership page. If you are already a member, login for access or contact us to setup your account.
