Every motorist knows what it’s like to pull up to a stop light beside a car whose driver has the sound system cranked to such ear-splitting decibels you can actually see the windows shaking.~

In Colin Novak’s ideal car of the not-so-distant future, the rear window will be vibrating—not as an unpleasant side effect, but deliberately, because that glass will be a crucial component of the vehicle’s audio system.

“If we can move the glass in a particular fashion, then we can make the window act as a speaker,” said Novak, an AUTO21 researcher and assistant professor in mechanical, automotive and materials engineering, who is hopeful the technology can be perfected and marketed for mass production.

Novak’s team included nine graduate students who developed a piezoelectric actuator, a bar shaped device which receives the signal from the audio system and transmits it to rigid, but highly sensitive springs that run along the bottom of the window, causing it to pulsate with the music.

The system eliminates the conventional sub-woofer, freeing up more space and cutting fuel consumption by reducing the car’s weight and the amount of electrical current required to run the audio system. And it drastically reduces the amount of noise heard outside the car when the music is louder.

“Think of a speaker as an enclosure,” Novak said while sitting in the driver seat of a Chrysler 300 being used as a test vehicle for the system. “We’re actually sitting inside the enclosure. You hear it inside, but not nearly as much outside.”

Novak’s students are focusing on how to improve the quality of the sound generated by the glass speaker. Other AUTO21 schools involved in the $400,000 project include the University of Waterloo, McGill, and the University of Calgary, which is examining the manufacturability of the system.

Read an interview about the system with Novak and Globe and Mail automotive columnist Michael Vaughan

Colin Novak inspects the springs at the bottom of a test car's rear window which allow the glass to operate as a speaker.
 

News Story Courtesy of UWin Daily News