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Bose’s involvement in car audio goes beyond its built-in speakers. The American firm has indeed unveiled its next technologies intended to improve sound comfort on board.
Developing and creating in-car sound systems is the most visible and well-known part of Bose’s business in the automotive world. The American audio specialist can indeed boast of partnerships as numerous as they are varied: at Nissan/Renault, Mazda, Porsche, Opel or even Hyundai, Bose options are found both on city cars and on resolutely sporty models. As you have probably seen in our very recent dossier devoted to acoustic research at Renault, sound reproduction is not the only problem car manufacturers face when designing a vehicle. And on these other subjects, Bose also offers the fruit of its research in signal processing and active noise reduction.
Route Noice Control: a system to eliminate road noise
Car manufacturers and specialized audio brands have already looked into managing perceived on-board noise through acoustic/electronic solutions. At Bose, controlling the noise generated by the engine of a combustion engine vehicle has for more than 10 years been the task of two in-house technologies, Engine Harmonic Cancellation and Engine Harmonic Enhancement: the timbre of the latter is analyzed beforehand during vehicle design and then in real time while driving in order to reduce perceived noise (signal broadcast in phase opposition by the vehicle’s loudspeakers) or on the contrary to optimize/modify it according to specifications defined by the Car manufacturer.
The rise in power of the electric vehicle has raised a new noise problem, this time at rolling level, much more perceptible since it is no longer masked by that of the internal combustion engine. This problem once again finds an answer at Bose via electronics and “Road Noise Control”. This system no longer works directly on very precise and very low frequencies, but on a much wider band between 40 and 400 Hz. Obviously determined to outdo its few competitors and to forge as many partnerships as possible, Bose presents his system as very responsive and adaptable.
An accelerometer is placed near each wheel to measure changes in vibration in real time. The operating principle then remains the same as for engine noise reduction, again with the use of the vehicle’s reproduction system, and a network of microphones is placed in the passenger compartment to ensure good performance of the system. As for adaptability, Bose ensures that its algorithm is calibrated to anticipate a certain evolution over time, among other things depending on the level of tire wear. We were able to carry out a brief test in a situation on board a demonstration vehicle (with the possibility of engaging or not the RNC system as desired, which is absolutely not the goal on a production vehicle intended for the general public): the result is certainly not breathtaking, but we have nevertheless detected a certain level of efficiency in erasing the noise generated on a fairly old bitumen road, in particular when passing over certain defects in the roadway which become practically “ transparent”.
In the future, Bose would like to develop its device to tackle an even larger frequency range and higher frequencies, in particular to counter the noise caused by the wind at higher speeds: a challenge that promises to be particularly arduous when you know that it already represents a small challenge in itself for Bluetooth headphones and earphones with active noise reduction, where the volume to be isolated is infinitely less important and where there is no sweetspot problem.
Create different sound bubbles in the car with SeatCentric
Bose also concocted a very quick demonstration of SeatCentric, a Bose technology that aims to create a personalized sound experience for each position in the cabin. In principle, the vehicle, equipped with both its “conventional” sound system and pairs of UltraNearField speakers housed in each seat (either in the headrest or in the upper part of the backrest), is capable to broadcast different content, or simply to manage their individual listening volume. A system that can be practical for making calls without disturbing or sharing content with passengers, or for enjoying music while disturbing those who want to rest on board as little as possible, for example.
© The Digital / Bose
The demonstration above all allowed us to observe the individual management of the volume, which turns out to be more practical than accurate for sound reproduction, and a driver call/passenger music listening situation which proved to be quite convincing: with a level reasonable listening, it was particularly difficult to follow the conversation that was happening on the driver’s side and, conversely, the conversation on the driver’s side was clear and not polluted by the music in progress. The SeatCentric technology, still in development, aims to truly enable users to have a personalized listening experience, and it is not excluded that we can see it in action over the next few years.
Bose is also getting into “3D audio” with its 3DX technology
Like Bang & Olufsen with Audio, Arkamys with Renaud or even Sennheiser, Bose also wants to stay on top of sound features and will therefore offer an audio system capable of offering a 3D sound experience. Simply called 3DX, this technology is based on a system composed of a set of “classic” speakers (housed in the cavities usually used), UltraNearField speakers to reinforce the sound presence and improve the perception of the scene , and several loudspeakers in the upper part of the cabin to recreate a sensation of sound elevation.
Everything is governed by the signal processing algorithms developed by Bose (including the SurroundStage already in use on certain models) which, for the moment, only act by applying an upmix to any stereo source. Bose assures that it will closely follow the development of 3D audio formats in the music industry to optimize its technology, already cut out for the exercise. The future will tell us if the American manufacturer will achieve its ends…