COAXING better quality sound from your loudspeakers could soon be taking a
tropical turn. A Japanese papermaking company is helping to develop a speaker
diaphragm made from paper that began as waste banana leaves. It says the
material has far better sound qualities than conventional materials.
Normally made out of paper, a speaker diaphragm needs to be highly elastic,
able to dampen vibrations quickly (a quality known as its loss factor), and be
light enough to move easily when vibrated by the speaker鈥檚 electromagnet.
鈥淲e started using waste banana leaves in our traditional paper-making process
to make high-quality calligraphy paper,鈥� says Rikio Imamura, president of the
Yamaichi Washi Kougyou paper company. 鈥淏ut it turns out that the paper has just
the right qualities to make excellent speaker diaphragms, because the fibres are
not homogeneous.鈥� All diaphragms resonate at a preferred frequency, but the lack
of homogeneity in banana fibres may help improve sound quality by reducing the
resonance.
Advertisement
Hi-fi firm Akimashi Foster Denki is experimenting with the paper to find out
why its properties are so favourable and how to improve on them. Seiki Suzuki,
of Mitsubishi Electric鈥檚 speaker engineering division, says he is intrigued by
it. 鈥淏anana fibres may have the characteristic of damping sound,鈥� he says. 鈥淭hat
could mean the paper would have a high loss factor.鈥�