New technology turns car cab into speakerFebruary 17, 2020
The next generation of immersive sound technology makes cars lighter and better sound quality.
Most premium car manufacturers have used active sound technology to get rid of unwanted resonance by sending noise-canceling signals through speakers or using active engine mounts to suppress vibrations – especially on models that use cylinder deactivation technology.
At the Consumer Electronics Show, Continental AG showed off a soundless immersive sound system developed in collaboration with Sennheiser, a premium sound specialist. Although the Ac2ated system is not a sound cancellation system, it uses an unusual approach to broadcast sound in the car.
Instead of conventional speakers, the system turns the interior panels of the car into the surface of the speakers. Continental compares technology with how the wooden body of a musical string instrument, such as a violin or cello, acts as a resonant chamber for playing sound during a game. In this case, selected parts of the surface inside the car vibrate like the diaphragm of a speaker to create sound.
Small actuators attached to the rear of the panels and hidden from view excite the exposed surfaces of the cab to create sound. Frequency ranges typically handled by specific sizes and types of speakers are created by vibrating surfaces of various sizes, such as front pillar trim, door trim, roof lining and rear shelf.
Sennheiser’s Ambeo 3D sound technology for immersive sound has been integrated with Ac2ated technology. At a strictly practical level, using activated surfaces saves space and weight. Continental claims that a conventional audio system can weigh up to 40 kg, but when using existing surfaces, it can reduce it by 75–90%.
Losing weight in cars is critical to reducing fuel consumption or increasing the range of electric cars, and it is quite expensive. Aluminum, carbon fiber, magnesium and light steels are more expensive. The ability to “cut” more than 30 kg into one of the functions that are required by most customers, while receiving a more desirable product, is a win-win for car manufacturers.
Perhaps even more radical is the Harman Individual Sound Zone (ISZ) system, which allows every passenger in the car to listen to their audio without headphones. Two small micro speakers installed in each headrest interact with sound waves from standard audio speakers to change what everyone hears. In addition, Electro Dynamic’s flat speakers (EDPL), one above each passenger, project a downward sound, so only one person can hear it.
The system allows passengers to listen to their own sound without hearing others, and only the driver should listen to driving-related commands, such as navigation instructions or other signals from the car. The system also allows passengers to receive a phone call and transfer it to someone else in the car. Even if two people listen to the same audio channel, they can adjust the volume individually.