Tinfoil and baking paper could replace conventional loudspeakers

Every commuter or plane passenger will be familiar with the frustration of straining to hear travel announcements.

But, thanks to senior engineers at Warwick, such aggravation could soon be a thing of the past.

Two members of the University’s Department of Engineering, Dr Duncan Billson and Professor David Hutchins (both members of the institution’s company Warwick Audio Technologies), have created a groundbreaking loudspeaker system that could revolutionise public announcements.

The two academics began their investigations into the innovation using nothing but two sheets of tinfoil with an insulating layer of baking paper which enabled the device to produce sound.

The “Flat, Flexible Loudspeaker” (FFL) – as the development has been hailed – is seen as a replacement for conventional speakers as its sound waves are able to project further and more clearly than its predecessor.

At just 0.25mm thick, the FFL can be hung on a wall rather like a picture, concealed within ceiling tiles or in the interior of a car. According to Steve Couchman, CEO of Warwick Audio Technologies, the new technology could quite easily replace the current speaker systems found in homes and motor vehicles as well as those in public spaces.

“We believe this is a truly innovative technology. Its size and flexibility means it can be used in all sorts of areas where space is at a premium. Audio visual companies are investigating its use as point of sale posters for smart audio messaging and car manufacturers are particularly interested in it for its light weight and thinness, which means it can be incorporated into the headlining of cars, rather than lower down in the interior,” he said.

Conventional speakers convert electric signals into sound by generating a magnetic field that subsequently causes a mechanical cone to vibrate and make noise.

The FFL cuts out a number of these stages and instead works by responding to the electrical signal to produce sound far more efficiently. It produces a plane wave which incorporates high directivity as well as accurate sound imaging.

This function could change the face of announcement systems in transport terminals all over the world. Couchman said, “the sound produced by FFLs can be directed straight at its intended audience.

“The sound volume and quality does not deteriorate as it does in conventional speakers, which means that public announcements in passenger terminals, for example, could be clearer, crisper, and easier to hear.”