Automotive designs that reduce car weight represent a key strategy for improving fuel economy. Typically, such designs encompass numerous small reductions of a pound or two. But when German automotive components manufacturer Continental AG decided to look at using a car's dashboard as an audio speaker, it hit upon a strategy that could mean not only a significant weight reduction but also an enhanced "surround-sound" audio experience for car occupants.
The cleverly-named Ac2ated Sound boasts excellent acoustics thanks to its ability to place different types of audio frequencies in areas of the car where they can be most faithfully reproduced: low-pitched sounds come from stiff, heavy components such as the rear window; higher frequencies come from the thin front vertical supports that hold the windshield in place; and midrange sound is produced by the windshield, the dashboard, the seat frames and the floor.
Using the car's interior to replace typical speaker components such as woofers and tweeters is made possible by transducers – lightweight devices that convert electrical energy into mechanical vibrations through use of a magnet wrapped in copper coil. According to the company, the principle of using interior surfaces to generate sound is based on expertise in vehicle noise, vibration and harshness, also known as NVH. Continental compares the technology to the principle behind a violin: a bow is used to make the strings vibrate, and that vibration is transmitted to the body of the instrument itself in order to produce sound.
The Ac2ated Sound speakerless audio system was recognized as an honoree in the In-Vehicle Audio/Video product category for the 2018 edition of the Consumer Technology Association's CES trade show. According to a recent article in the New York Times, the technology should begin to appear in the consumer automotive market by 2021, with various available permutations of sound quality based upon the number of active transducers.