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New Speakers Make Music With Seaweed, Rice Husks

July 30, 1992

TOKYO (AP) _ Some of Japan’s newest speakers convey the clear tones of Luciano Pavarotti or a Stradivari violin through vibrating seaweed, rice husks or bacterial waste.

Japanese audio companies say Handel’s Water Music, Schubert’s Trout Quintet, Vivaldi’s Four Seasons and almost any other music sounds better from speakers made of such exotic natural materials.

Sharp Corp. makes speakers with bamboo grass, Onkyo uses fibers from the sea squirt, Pioneer chose seaweed, Sanyo cooks rice husks and Sony gathers strands of waste excreted by bacteria.

The speakers are on sale in Japan and a few are being introduced in the United States. Initially, the natural materials are being used primarily in high-end speakers, increasing prices only marginally.

For decades, most manufacturers relied on paper pulp for speaker cones, which vibrate to create sound. But pulp tears easily, absorbs moisture and does not perform well at high frequencies.

When artificial materials such as polypropylene and carbon-fiber reinforced resins became available, many companies used them for speaker cones because of their strength, durability and immunity to dampness.

″However, strong physical properties don’t necessarily result in good sound,″ said Yoichi Arita of Sanyo’s audio-visual products division. ″As a result, we’ve started experimenting with many different kinds of natural materials.″

Japanese companies have never been as successful at making speakers, considered by some to be more an art than a science, as at designing amplifiers or televisions. They hope to enliven sales with the new materials.

Designers of the speakers say they believe natural materials are better at re-creating sounds from acoustic instruments and produce a result more pleasing to the ear.

One theory is that natural materials create a harmonic distortion less grating than that of synthetic materials.

Onkyo officials say the uniform molecular structures of materials like carbon or polypropylene also tend to give music an artificial ring.

Whatever the reasons, many of the new speakers are pleasant to listen to, with clear, effortless high frequencies and very little harshness.

Pioneer says it tried dozens of materials for its S-5000 speakers, which cost $8,000, before choosing a diamond tweeter cone and a woofer made with seaweed.

Sony’s best speakers and headphones use a cellulose fiber made from the waste products of bacteria. The special strain of bacteria reproduces rapidly in a sugar-water solution while excreting strands of waste that are used to create lightweight, durable cones with low resonance, the company said.

Other companies combine pulp with other natural materials.

Cones made of the long, thick fibers of pure pulp do not transmit sound well at higher frequencies, and give it a cloudy veil. Sanyo, Sharp and Onkyo say they have overcome the problem by mixing pulp with finer natural fibers in cones that are stronger, more rigid and have better high-frequency response.

Sharp uses chishima bamboo grass from the highlands of northern Hokkaido island because of its strong, thin, dense fibers.

Onkyo uses fiber made from the tunic, or outer protective layer, of sea squirts, primitive marine organisms that look like potatoes and grow on piers, rocks, and ship hulls.

Sanyo heats rice husks for five hours to create a porous ceramic and mixes it with pulp to make speaker cones that, the company says, produce music with less coloration than do synthetic materials.

Company officials concede another reason for choosing the new materials is that bamboo, rice and seafood sound good in advertising copy aimed at a Japanese audience.

″We believe that natural, renewable products will appeal to Japanese consumers,″ said Arita of Sanyo.

-07-30-92 0004EDT

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