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Side Soundports

There’s a Hole in the Bucket

by Cyndy Burton

A Discussion of Sideports, with Contributions from Kenny Hill, Alan Carruth, Roger Thurman, John Monteleone, Mike Doolin, and Robert Ruck

previously published in American Lutherie #91, 2007

See also,
Sidewaysby John Monteleone
“Herr Helmholtz’ Tube” by Mike Doolin
“Three Holes are Better than One” Robert Ruck



Just in case we become too self-satisfied with our “discovery” of ports, Alain Bieber, in his article on lyra guitars (AL#88, p. 16), points us to the Neapolitan Gennaro Fabricatore’s ported lyras from the early 1800s. (Alain ported his own contemporary lyra guitar, too.) So we know prominent makers were putting holes in the sides of their instruments in the late 1700s, early 1800s. Many of us are also aware of Carleen Hutchins’ groundwork in the early 1980s. Her “Le Greyère” violin, with sixty-five sideports, has provided a wealth of data about violin resonances since it was made in 1982. She donated the violin to the National Music Museum in 2002. See some great photos of Le Greyère and a list of publications reporting on that research at collections.nmmusd.org/Archives/NewViolinFamily/Hutchinscheeseviolin.html.

People are sensitive about putting holes in things. Many guitarists — perhaps more classical guitarists than others — find the ports some sort of denigration, a violation of the sanctity of the guitar’s perfect form. In all fairness, we’ve met with very strong feelings on both sides of the port issue. Luckily, our customer was very open to the idea. He’s not a concertizing musician, but he’s a serious player, and occasionally he plays publicly for special events. We wanted to try ports for him because he has a hearing loss, and we thought ports would be a great way for him to hear himself better. At that time, Robert Ruck had made about a hundred ported guitars, so we figured he had worked out the kinks. He kindly advised us on size, location, and so on. We followed his lead. The result is a wonderful instrument that the owner truly appreciates. We love the feedback — the monitor effect for the player — and when we tested it in a small auditorium with an overflowing audience, we could not discern any loss of projection or quality of sound. But was it louder? Our evidence was very meager and inconclusive. Many makers are adamant that it’s louder with the ports open for both the player and the audience.

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Using the Golden Section to Design a Kamanché

Using the Golden Section to Design a Kamanché

by Ahanali Jahandideh, Mitra Jahandideh, Hadi Abbaszadeh, and Samad Jahandideh

Originally published in American Lutherie #98, 2009



The kamanché is a Persian bowed string instrument related to the violin. (See “Building the Kamanché” by Nasser Shirazi, AL#4, p. 27 and BRBAL1, p. 126, and GAL Instrument Plan #9. The kamanché has a long neck and a spheroid sound chamber made from gourd or wooden staves, which is usually covered on the playing side with skin from a lamb, goat, or fish. It is widely played in classical music of Iran, Azerbaijan, Uzbekistan, and Turkmenistan, with slight variations in structure.

The Golden Section (also known as the Golden Mean, Ratio, or Proportion) is a ratio defined by the number phi (Φ=1.618033988...). It has been used in designing violins and other musical instruments, but for the first time we used it to design an Iranian instrument.

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Questions: Amplifying Flattop Bass

Questions: Amplifying Flattop Bass

by Harry Fleishman

Originally published in American Lutherie #65, 2001 and Big Red Book of American Lutherie Volume Six, 2013



Mark Brantley of Appleton, Minnesota asks:

I recently ordered Tim Olsen’s plans for the Flattop Bass (GAL Plan #13). Do you have any advice on a good electric pickup for it?


Harry Fleishman of Boulder, Colorado responds:

It’s difficult to offer too much advice about amplifying your acoustic bass without more input about how loud you need to play, how high a fidelity to the instrument’s actual acoustic voice you want, and what your budget is; but here goes anyway.

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Questions: Guitar Air Cavity

Questions: Guitar Air Cavity

by Art Davis, Alan Carruth, and Joe D. Franklin

Originally published in American Lutherie #63, 2000 and Big Red Book of American Lutherie Volume Six, 2013



Tom Blackshear of San Antonio, Texas asks:

Is there a formula for measuring the air cavity of a guitar box, then figuring out how to keep the same amount of air with slightly different box dimensions?


Art Davis of San Diego, California responds:

Use bird seed. It’s not totally accurate but it’s easy. Pour it in, pour it out, and measure it. Hold the guitar really well because ten or twenty pounds of bird seed is heavy. Also, as per W.D. Allen’s, “Basics of Air Resonances,” in The Big Red Book of American Lutherie Volume 1, changing the air volume doesn’t always do what you think it’s going to.

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A Method for the Design of the Guitar Body Outline

A Method for the Design of the Guitar Body Outline

by R.M. Mottola

Originally published in American Lutherie #97, 2009

See also,
Parametric Models of Guitar Cutaways by R.M. Mottola
A Method For the Design Of the Guitar Body Outline Part 3: Compound Radius Curves by R.M. Mottola



One of the most tedious and time consuming aspects of designing a new guitar for me is the process of designing the body outline. The body outlines of my early instruments were the results of many hours of labor, usually over the course of many weeks. This process was so time consuming that I would often forgo it entirely, opting to reuse an existing body outline as is, or scaling up a guitar outline for use in an acoustic bass guitar. But over the years I’ve settled into a method for guitar body outline design which is far less tedious and consumes far less time than did my original efforts. This method involves the use of a standard model of the guitar outline. Use of this standard model helps to make the process of developing an outline more standard as well, and this in turn has resulted in the development of techniques which save time and frustration.

In this article I will be outlining the model and discussing some common guitar body types in the context of this model. In talking about the design method which makes use of the model, I’ll try to touch on some of the generic qualities of guitar body outlines and how they can be quantified in terms of the model. Finally, some of the tools and techniques of the method will be detailed. Please note that what I am discussing here is only the mechanical aspects of a body design. Issues of acoustics or ergonomics are not covered. Also note that this method works equally well with either pencil and paper or CAD drawing tools, although there are some differences in how these tools are used.

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