Car Sound Revolution: Forget the Subwoofer

Good sound inside the car is a must have. But the cars of tomorrow will not be fitted with conventional loudspeakers, yet they will have unprecedented sound quality. This will improve safety at the same time.

Concert hall on wheels

Is there anyone who doesn’t know the KENWOOD windshield sticker? It is a statement in itself and for a long time it epitomized powerful subwoofers, especially among customizing freaks. Today many cars still drive around carrying several kilograms of hi-fi equipment. The large number of components can push the weight of the equipment to up to 40 kg The systems therefore have high energy consumption and need a lot of space inside the vehicle. This was reason enough for Continental and the hi-fi specialists at Sennheiser to re-invent automotive sound technology. The key is that the interior functions as a resonator – rather like the wooden body of a violin. Parts of the chassis, the door cladding and the rear shelf serve as resonators. The engineers questioned whether there is any need at all for conventional loudspeakers if the car can produce the sound itself.

This led to the “Ac2ated Sound System,” in which conventional loudspeakers are replaced with actuators that create sound by exciting certain surfaces in the vehicle interior to make them vibrate. This system offers reductions in weight and volume of up to 90 percent compared with the sound systems on the market today. The advantage is that the system can be integrated into any vehicle model. The new technology will be a benefit in e-cars in particular, where it is especially important to reduce weight and the amount of space occupied. But there’s more: an integrated algorithm automatically converts stereo sources into 3-D sound. The software analyzes the content and mixes the sound. This provides the driver and passengers with a completely new all-round sound experience like sitting in a concert hall.

Continental and Sennheiser bring concerts into the vehicle – Copyright: Sennheiser electronic GmbH & Co. KG /

The sound of safety

The latest developments also touch on the subject of safety. A large number of sounds demand more of the driver’s attention, such as those from turning indicators, the parking assistant, the GPS, warning signals and phone calls. Information therefore has to be supplied in a way that does not distract the driver and in certain situations other noises will automatically fade into the background. The future generation of audio management will therefore integrate and bundle all the acoustic sources into one. It will prioritize sounds and use them depending on the situation. If, for example, another road user approaches in a dangerous manner from the right, an acoustic signal will sound on this side to alert the driver while all other noises fall silent. In addition, a range of different warning beeps can be applied, for instance more urgent sounds to indicate a cyclist in the vehicle’s blind spot when the driver wants to make a turn. And when the traffic data and information from the assistance systems are relayed acoustically, the driver will not have to estimate distances or read displays any more.

The good old audio cassette is becoming a rare sight in cars. First it had to give way to the CD, and now Spotify. – Copyright: Unsplash

"Alexa, please play my favorite Lady Gaga song"

Soon users will be able to turn the audio system Ac2uated Sound on and select their favorite track using the Alexa assistant. On-board music used to come from the six-disc CD changer in the trunk – or else the driver had to search through the radio channels. But today audio streaming services like Spotify, Apple and Amazon Music give drivers access to an almost limitless choice of music. For years Spotify has been the largest and best-known music provider. The company was founded in Sweden in 2006 and now has over 130 million subscribers and offers around 50 million songs. Anyone who finds this overwhelming can in the future rely on recommendations from AI instead, which will learn the individual music tastes of the vehicle’s occupants. The intelligent technology registers whether a piece of music is played all the way to the end, sorts the selection by bass and mood, and even knows whether the drivers are on their way to work, on vacation or making a shopping trip. Furthermore, in the audio management system personal sounds can also be defined, which are not critical to safety. For example, loud chirping of birds when the doors are closed, or clips from movie soundtracks when the boss calls. Now there are no limits to creating soundscapes.

Stage Photo: © Sennheiser electronic GmbH & Co. KG /

Further articles