This is one of those cases where someone just kept plugging at the problem until one day inspiration struck.

Some engineering problems take longer to solve than others. Inventors struggled for decades to find the right filament material, before Thomas Edison tried carbon and made a practical light bulb.

Toshikatsu Kuwahata, an engineer at the audio factory of JVC (Victor Company of Japan Ltd.), in Yokohama, is no stranger to such lengthy struggles. He wrestled for more than 20 years with his own personal challenge—making a speaker cone that could be manufactured in quantity out of wood.

Why would anyone want to use wood to make a speaker cone?  It turns out that wood’s natural properties include the ability to propogate sound very quickly and its natural internal dampening effect leads to smoother frequency response.  The problem is that wood has to be deformed radically to make a speaker cone.  He tried several approaches, but either the wood cracked or the process was too expensive for mass production.

So, how did this inspiration come about?  At a restaurant:

Then, five years ago, a colleague, Satoshi Imamura, was dining at one of his favorite restaurants. Imamura contemplated the texture and malleability of the dried squid he was chewing. He asked the waiter how it had been prepared, and the waiter explained that the squid had been soaked in sake.

Imamura and Kuwahata tried soaking the speaker wood in sake. It worked! (They also tried Suntory whiskey; it didn’t. Imamura isn’t sure why, but he theorizes that there is something unique about the acids in sake, which is simply fermented, as opposed to those in whiskey, which is distilled after fermentation.)

The sake makes the wood sheets malleable but—crucially—without affecting their strength. The sheets are then infused with resin and a mold-release agent. The resin prevents the wood from absorbing moisture, helping it to retain its shape in high temperature and humidity long after it’s been molded into the shape of a speaker cone.

It just proves that you never know where you’ll find a solution for a thorny problem.