Audio firm Magna International Inc has come up with a novel way of improving your car's sound system: using the rear window as an enormous subwoofer.

The concept is fairly simple, turning the entire rear window into a speaker with two exciters sited at the bottom of the glass, using the window itself as the membrane of the speaker. Similar technology has been seen before but not in car-based applications and not for lower frequency notes.

Known as AcoustiVision, the technology has been demonstrated on a Chrysler 300, though it will work in any car with a rear screen. A signal from the stereo goes through an amplifier in the trunk to boost output from 12 volts to 200, which then goes into the exciters to generate sound.

The vibrations should prove no danger to the integrity of the glass as screens are mounted in a sealant that allows vibration. Product director Greg Rizzo said "It is a whole new way to generate sound in a car," Rizzo said. "There are still tweeters up front but the glass replaces a big subwoofer in the trunk"

The benefits of the AcoustiVision system include lower weight than a large subwoofer installation and little impact on trunk space compared to a typical sub. It also uses less energy to power.

Thankfully for the sanity of pedestrians, the sound can only be heard inside the car. Magna has been developing the system for four years now and they now aim to secure contracts with automakers and increase production capacity.

The AcoustiVision system could be in production for the 2015 model year.

[Detroit News]