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Depending on many interrelated variables, from the force exerted on the strings by the player to the stiffness, density and shape of an instrument’s parts, a layered field of sound emanates, sometimes containing dozens of distinctive overtones and harmonics.
Balsa 4, one of several prototypes by Douglas Martin. The finished instrument was played and tested at an annual workshop on violin design.
Perfect Violin: Does Artistry or Physics Hold Secret? (June 14, 1994)
Web Links
Related Organizations From the Violin Society of America
Fiddle Physics (The Why Files)
A Schleske design, left, was preferred to a 1721 Stradivarius when played by Ingolf Turban, a concert violinist.
Some sounds disperse in the air evenly in all directions, while others — especially high notes on a violin — push outward in a particular direction, funneled by the shape of the instrument.
Particularly important, Dr. Bissinger said, is determining which factors translate the side-to-side sawing of a bow on a string into vertical motions of the violin top. “Up and down is what matters,” he said.
Other vibrations travel in the body — at different speeds reflecting the orientation of wood grain — setting up all manner of ripples and bouncing waves and more ripples.
In instruments built entirely of meshed graphite fibers, the vibrations move uniformly, offering both challenges and opportunities to instrument makers.
Another important influence, particularly on low violin notes, is the movement of air in and out of the f-holes, Dr. Bissinger said. If the dimensions are right, the air sloshes forward and back like disturbed water in a bathtub (or air in an organ’s pipes) at rates that increase the instrument’s volume.
The materials in the body matter because they determine how much of the energy imparted to an instrument moves into the surrounding air as sound and how much is dissipated as heat within the matrix of molecules that make up the instrument’s body.
That damping effect is not all bad, guitar and violin makers say, and may be one of the characteristics that give a mellow tone to older instruments in contrast to the almost metallic brightness sometimes heard in new ones.
In September, Dr. Bissinger ran three days of tests on two violins built by Stradivari and one by Guarneri del Gesù — worth a combined $14 million or so — as well as instruments by Mr. Curtin and Sam Zygmuntowicz, a violin maker from Brooklyn.
By comparing the response of the legendary instruments to the new ones, and to data from a batch of bad student violins, Dr. Bissinger said, he is trying to develop an anatomical guide of sorts, revealing which features determine the qualities of which parts of a violin’s sound, from the lowest notes to the highest trills.
“I like the bad ones as much as the good,” he said. “How can you know beautiful if you don’t know ugly?”
Dr. Bissinger said that the experiments with balsa and carbon were clearly helping expand understanding of the boundaries of violin sound, but that they have “a tall hill to climb” to compete in the marketplace with traditional instruments, which have already shown their ability to last 300 years and hold up to the pounding of a Paganini solo.
At the University of New South Wales in Sydney, Australia, another physicist, Joe Wolfe, has assembled a team that is testing whether an instrument’s age or the amount it has been played change its sound.
In interviews, instrument players and dealers expressed a conviction that vintage does matter, and several theories have been proposed for how aging changes the structure of wood in ways that affect sound.
But Dr. Wolfe and Ra Inta, another member of the Australian team, said that rigorous experimental evidence was scant, with a couple of recent studies, for example, offering conflicting findings.
They have a long-term study under way on two identical violins built by a local maker, Harry Vatiliotis, from the same 80-year-old slabs of spruce and maple. One is sitting nearly untouched in a museum and the other is in constant use in the hands of a concert violinist. But it will be many years before enough time has passed to determine if all those vibrations from continual bowing have altered the wood in substantive ways, the researchers said.
Such scientific analysis has produced some trepidation among traditionalists, Mr. Curtin said. “There’s a kind of a nervousness that the mystery will go out of it, the bubble will be pricked and it’ll all just be ordinary. It’ll be technology. There’s almost a cultural sense that the violin is the last repository of mystery. The fact that we don’t understand the violin adds to its allure.”
Mr. Curtin, who is also experimenting with balsa but is laminating a thin veneer of tougher spruce on top, said such fears were unfounded. “To me, understanding always makes things more interesting, not less. That’s been true for biology. I think it’s the same with acoustics.”
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