Posted on June 21, 2025September 15, 2025 by Dale Phillips The Helmholtz Resonance The Helmholtz Resonance A Brief and Not-Too-Technical Introduction to the History and Theory of the Lowest Sound-Producing Mode, and Some Practical Considerations for Instrument Designers by R.M. Mottola Originally published in American Lutherie #82, 2005 and Big Red Book of American Lutherie Volume Seven, 2015 Research in physics and acoustics of stringed instruments shows us the mechanism by which sound is produced by those instruments. The plates of the instruments and the air inside vibrate in various patterns, each pattern producing sound in a range around a certain frequency. Each of these patterns can be considered to be a resonator, each with its own characteristics. Some of these resonators exist as modes of vibration of different areas of the plates of an instrument, and some are modes of vibration of the air inside the instrument. One of the air resonators is composed of the mass of air inside the instrument and the mass of air within and around the soundhole. The natural frequency of this resonator is near the lowest note that an instrument can make. It is generally labeled the A0 resonance, the letter A standing for the word “air” and the numeral 0 indicating that this is the first in a series of air resonances. This resonance is also referred to as the so-called Helmholtz resonance. Understanding how this resonance works in stringed instruments is not difficult, particularly given a historical perspective. Complete understanding involves some math, but a practical understanding can be had without it. Therefore, I am putting off presenting the formulae in the main article and have included them in a sidebar. Become A Member to Continue Reading This Article This article is part of the Articles Online featured on our website for Guild members. To view this and other web articles, join the Guild of American Luthiers. For details, visit the membership page. MEMBERS: login for access or contact us to setup your account.
Posted on June 21, 2025September 15, 2025 by Dale Phillips The Helmholtz Formula The Helmholtz Formula by R.M. Mottola Originally published in American Lutherie #82, 2005 and Big Red Book of American Lutherie Volume Seven, 2015 The resonant frequency of a mass spring resonator can be determined by the following formula: Become A Member to Continue Reading This Article This article is part of the Articles Online featured on our website for Guild members. To view this and other web articles, join the Guild of American Luthiers. For details, visit the membership page. MEMBERS: login for access or contact us to setup your account.
Posted on January 13, 2025May 14, 2025 by Dale Phillips Is “Guitar Design” an Oxymoron? Is “Guitar Design” an Oxymoron? by Steve Klein from his 2001 GAL Convention lecture Originally published in American Lutherie #76, 2003 and Big Red Book of American Lutherie Volume Seven, 2015 Webster’s defines “oxymoron” as “a figure of speech in which opposites or contradictory ideas or terms are combined, e.g., sweet sorrow” and my personal favorite, “thunderous silence.” The second definition of “design” is “being able to make original plans.” When Todd Brotherton called to ask if I would speak here today, he mentioned that I’ve been doing my design thing for near on thirty years. And almost in the same breath, he called my ideas new and innovative. What’s wrong with this picture? Palm pilots are new. Downloading MP3s is new. Viagra is new. My ideas are no longer new. So why are the things that I’m trying to do still thought of as new? Or we might ask, why is the musical world so slow to change, when everything else in our culture seems to be on the fast track? Why might it take so long for acoustic guitars to evolve? This begs some questions, such as: 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 July 8, 2024May 15, 2025 by Dale Phillips Not Only Cones Make It — and Cylinders Almost Do Not Only Cones Make It — and Cylinders Almost Do by F.A. Jaén Originally published in American Lutherie #101, 2010 In the years since Tim Olsen’s article “Cylinders Don’t Make It” appeared in AL#8 (Winter 1986; also BRBAL1) the main ideas presented there have been accepted, developed, and finally, simplified and distorted. Many, including myself, remembered it more like “Only Cones Make It.” The first indication that something in my ideas was wrong was when I made a CAD model of a fretboard some time ago. I wanted it to have a constant curvature radius of 300MM (around 12"). There are many customers that still want that, in spite of offering well-designed conical-shaped fingerboards. My first thought was to draw two circles, 12" diameter, one directly above the other, at the distance from nut to end. After that, I would trace two diverging straight lines connecting both circles and defining both the edges of the fretboard and the widths at its ends. The surface could then be generated by moving one of the edge lines towards the other, using the end circles as rail curves (what is known as a “sweep” command in many CAD packages). Become A Member to Continue Reading This Article This article is part of the Articles Online featured on our website for Guild members. To view this and other web articles, join the Guild of American Luthiers. Members also receive 3 annual issues of American Lutherie and get discounts on products. For details, visit the membership page. MEMBERS: login for access or contact us to setup your account.
Posted on July 8, 2024May 9, 2025 by Dale Phillips At the Outer Limits of Solid Geometry: The “Twisted Neck” Guitar At the Outer Limits of Solid Geometry: The “Twisted Neck” Guitar by Leo Burrell Originally published in American Lutherie #12, 1987 and Big Red Book of American Lutherie Volume One, 2000 I was greatly amused by remembering my own struggles while reading the articles in AL#8 about the compound radius of the fretboard. I was actually practicing these techniques before knowing what a plain old radius is. I have only been in the music business since applying for patent letters for my naturally rotated (twisted) string assembly (all of the components that define the string alignment: nut, neck, bridge, top of the body). That was April 1984. And I never would have built an instrument at all, let alone carve a compound radius, if the “Music Moguls” had had any respect for my invention. But they didn’t, so I did. I enclose a photograph of me holding an instrument I modified in June 1984. I shaped the neck from a solid block of cherry given to me by Dan Rowe, shop teacher at Western Beaver High School, Industry, Pennsylvania. I whittled and otherwise shaped it during evenings for about two weeks, using the kitchen counter for a workbench. Oddly enough, I roughly followed the procedure you described in your article “Cylinders Don’t Make It” to shape the fingerboard. However, in my case, the procedure was complicated by the approximate 45° rotation. Become A Member to Continue Reading This Article This article is part of the Articles Online featured on our website for Guild members. To view this and other web articles, join the Guild of American Luthiers. Members also receive 3 annual issues of American Lutherie and get discounts on products. For details, visit the membership page. MEMBERS: login for access or contact us to setup your account.
