tuningblog.eu Your magazine about tuning the car
Recently updated on December 20, 2022 at 11:28 am
More calm thanks to sound waves
With active driving noise compensation, the Mercedes-Maybach S-Class, which is already very quiet in the interior, becomes even quieter. Similar to noise-canceling headphones, the system uses anti-phase sound waves to reduce unwanted, low-frequency noise. The bass speakers of the Burmester are used for playback® High-end 4D surround sound system used.
Exciting the roadway generates low-frequency noises that can be perceived in the interior as an annoying roar or hum. In the Mercedes-Maybach S-Class with Active Noise Compensation there are six acceleration sensors on the chassis. They transmit reference signals to the control unit. With the help of a special algorithm, this information is used to calculate in advance which counter noise has to be generated. The matching sound waves, i.e. 180 degrees out of phase, are transmitted through the Burmester's bass speakers® High-end 4D surround sound system reproduced.
A corresponding BUS system ensures the transmission of the audio signals almost at supersonic speed. Because these have to be on the human ear at the same time as the sound caused by rolling. Only around three milliseconds are available for playback.
Since the noise behavior can change if the road surface changes or the speed varies, the system also uses four microphones in the interior for monitoring and adaptation. These additional microphones are very close to the passengers, right next to the microphones of the hands-free system.
The passengers cannot hear the anti-noise waves of the active driving noise compensation. But they are also generated when the Burmester® High-end 4D surround sound system is apparently switched off because the power amplifiers are always on. Active driving noise compensation, on the other hand, switches off automatically at low speeds below approx. 20 km / h and above approx. 180 km / h when the wind noise dominates. Even if the side windows or the sunroof is opened, no counter-noise is generated because the control system in the car is then different.
The active driving noise compensation was developed together with the Harman subsidiary HALOsonic.
(Article goes over several pages - page selection below)
