Stories tagged acoustics

Feb
07
2009

Stradivarious secret is in the sauce
Stradivarious secret is in the sauceCourtesy caribb

Stradivarius violins soaked in "secret sauce"

Having obtained minute wood samples from restorers working on Stradivarius and Guarneri instruments, scientists now have verified that the wood was treated with borax, fluorides, chromium and iron salts. Borax is a wood preservative and an insecticide. It makes sense that wood craftsmen would want to protect their creations from being chewed up by worms.

Joseph Nagyvary, a professor emeritus of biochemistry, first theorized in 1976 that chemicals used on the instruments – not merely the wood and the construction – are responsible for the distinctive sound of these violins." Texas A&M University

Joseph Nagyvary, a professor emeritus of biochemistry, along with Renald Guillemette, director of the electron microprobe laboratory, and Clifford Spiegelman, professor of statistics, all Texas A&M faculty members published their research in the current issue of the scientific journal Public Library of Science (PloSONE).

Learn more about Nagyvary's research

Source: "Secrets Of Stradivarius’ Unique Sound Revealed"
Nagyvary's website: Nagyvary Violins

A&T Professor Has Technology to Monitor Bridge Safety

"Dr. Mannur Sundaresan, professor of mechanical engineering, has developed a single channel continuous sensor that has the potential to detect and locate early crack growth in structures, thereby providing timely information to prevent catastrophic failures. This single channel continuous sensor can detect the leading edge of the acoustic emission event, occurring anywhere in the region covered by the sensor." North Carolina A&T State University

Apr
18
2007

The amphitheater at Epidaurus has acoustics so good you can hear a pin drop, even when the seats are packed with 15,000 people: Photo by Randy Peters from flickr.com
The amphitheater at Epidaurus has acoustics so good you can hear a pin drop, even when the seats are packed with 15,000 people: Photo by Randy Peters from flickr.com

The ancient Greek amphitheater at Epidaurus has long been famous for its marvelous sound qualities. Audience members in the back row could hear every sound, even as soft as a match being struck.

Until recently, no one has unlocked the secrets of these perfect acoustics. The Greeks themselves thought it was the shape of the amphitheater. But other theaters built on the same model could not reproduce the sound quality of Epidaurus.

Now, researchers at the Georgia Institute of Technology have finally solved the problem. They found that the limestone seats work as a filter to dampen the sound of the crowd, while at the same time amplifying the sounds from the stage, . Other amphitheaters used the same design but different materials, and were never able to duplicate the results.

Mar
18
2007

Stradavarius sound from graphite and balsa

Violin engineering: image modified from TheViolinSite.com via wikipedia
Violin engineering: image modified from TheViolinSite.com via wikipedia
Can we make violins today that sound as sweet as those made by Antonio Stradivari? Joseph Curtin (Ann Arbor, Mich.),who received a 2005 MacArthur Foundation “genius award” for his violin designs, thinks so. In reference to violins made by Douglas Martin, Curtin stated that

“the traditional violin became obsolete in early July of 2005.”

One of Mr. Martin's prototype violins, Balsa 4, when passed around at a violin design workshop at Oberlin College, startled the participants with its punch and responsiveness. Using balsa for lightness and graphite for stiffness, Martin is breaking the traditional violin design rules.

New materials "sing"

Another violin maker to use modern materials like graphite fibers is Martin Schleske. Ingolf Turban, a touring concert violinist, compared Mr. Schleske’s latest violin, which has a top made of a mix of spruce and graphite, with a 1721 Stradivarius by recording passages from Mozart’s Violin Concerto in D Major with each. He told Mr. Schleske he preferred the new one.

I have never been playing any violin with such a singing E string,” Mr. Turban said in a testimonial. “It is no longer like playing violin but like singing.”

Violin acoustics analysed in physics laboratory

George Bissinger, a physicist at East Carolina University in Greenville, N.C., is using medical-imaging gear, laser scanners, arrays of microphones and computers to measure and model how the parts of a violin react once energy is introduced by a bow, fingertip, pick or, in the laboratory, the repeated taps of a tiny hammer.

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.
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.

Want to learn more?

I recommend viewing the video and multimedia graphics found in the New York Times post, "String Theory: New Approaches to Instrument Design".