Looking Back For Better Sound

Throw away those cumbersome speakers on the parcel shelf - boffins have found out how to make the rear windscreen do the same job, but better. Amazingly, they claim to have turned the glass into a loudspeaker that gives crystal-clear sound.

Auto Express Car Reviews

17th March 2005

"We tested it against a premium sound system, and ours was better," said Urban Emborg of Swedish engineering consultancy Caran. The team worked out how to make the rear window vibrate, generating the low-frequency sounds which usually come from a subwoofer. Caran reckons the first see-through speaker will appear on new cars in 2007 - but he won't reveal which marque will fit them first. The Gothenburg company already counts Saab and Volvo among its clients.

Here's how it works. A row of tiny buttons along the bottom of the windscreen vibrate when they receive electronic signals from the amplifier. This makes the glass shake, generating sound.

"It works best with curved glass, as this is stiffer," Umborg added. "The sound stays inside the car and the glass does a better job than the usual bass subwoofer, but you will still need small speakers to generate the higher frequencies." The glass also uses less power than traditional speakers.