ECU physicist measures acoustics of famous violins
(July 30, 2006)
For almost two centuries scientists have searched for the essential measurable properties that separate good violins from bad violins.
In the past 30 years, East Carolina University physicist George Bissinger has made strides in this endeavor, using vibration, acoustics, and computer analyses to help violin makers craft better-sounding instruments with a National Science Foundation-funded project called VIOCADEAS (VIOlin Computer Aided Design Engineering Analysis System).
Bissinger, a professor at East Carolina University, worked this month with leading violin makers and the California-based Polytec, Inc., to expand his research using the company's 3-D laser scanning equipment.
Two legendary Stradivarius violins — the 1715 "Titian" and the 1734 "Willemotte," as well as the 1735 "Plowden" Guarneri del Gesu — were brought to Greenville and tested at Bissinger's laboratory at ECU. Violins by leading contemporary violin makers, Sam Zygmuntowicz and Joseph Curtin, were also tested.
There is a strongly held opinion that there are certain sound qualities associated with old Italian violins that modern instruments do not attain.
Zygmuntowicz, who works with these violins, said he was excited that Polytec's equipment would reveal the instruments' sonic properties.
"There is no visible measurement or point I've not seen on these violins," Zygmuntowicz said. "The important aspects of the violin are what we can't see. With sound, you can't see it because it's microscopic, but with this equipment, it all becomes very tangible. You can see and touch it."
Bissinger hopes these scans will reveal new ways that the violin vibrates and thus provide information on how it radiates sound, which will also be measured in an anechoic chamber during this experiment.
"We're getting a taste for how things move," Bissinger said. "It's more interesting to me from the science point of view. I can say, here are ways you can incorporate what you do with violins."
The violins also underwent CT scans at ECU's Leo W. Jenkins Cancer Center at the Brody School of Medicine.
Comparing these 3-D scans on superlative old Italian violins with previous “good” and “bad” modern violin results promises to generate new insights into violin sound production and violin quality, Bissinger said. Finally the map of essential material properties - stiffness, density, damping and shape – that govern the vibrations of any violin will be extended to these legendary violins.
"Basically, a very good violin sounds loud while still sounding beautiful," Zygmuntowicz said. "We know what it sounds like, but it won't tell us why it's good."
In addition to the violing makers, Violin Society of America members Fan Tao and Joseph Regh were also involved in this first-ever 3-D scan of legendary violins.