At this year’s Consumer Electronics Show (CES, Las Vegas, January 7-10), one of the things NXP will be talking about is our engineering collaboration with Bose. The arrangement, which makes Bose noise-cancelling technology more widely available in automobiles, promises to help consumers satisfy their craving for a quieter car environment.
You probably already know Bose as a leader in acoustics and sound engineering, and may even own a pair of their noise-cancelling headphones, which have become essential equipment for air travelers. The patented Bose technology deadens the roar of jet engines, so you can enjoy music, watch a movie, or just have some quiet time to sleep before reaching your destination.
The passenger cabin of an airliner is, by and large, a lot noisier than the interior cabin of most cars, but noise is still very much a factor in automobiles. In fact, for some time now, having a quiet interior has been a defining point for high-end models. One of the things people look for in luxury cars is how little engine noise they hear in the cabin. The idea is that no matter what the situation — whether you’re on the highway or stuck in traffic — the interior remains an oasis of peace and quiet.
Studies show that we spend more time in our cars than ever before, and having a quiet driving environment creates a better experience for drivers and passengers alike. Driving in a noisy car can be distracting, and can even make driving more dangerous, since exposure to noise can lead to driver fatigue. Also, having a quiet interior makes the car’s audio system sound better, and makes it easier to hear and be heard on handsfree phone calls.
Today’s cars are much quieter than their predecessors, but there’s still room for improvement. In particular, the latest cars have a variety of systems and components, including high-performance and high-efficiency powertrains that produce unfamiliar and unpleasant sounds. Automotive engineers look for ways to refine the sound in the cabin, but this adds time and cost to the development cycle.
Bose developed Active Sound Management technology as an alternative approach, drawing from more than 30 years of research in automotive acoustics and noise cancelling for aviation, military, and consumer applications. Unlike conventional noise-management systems that rely on mechanical solutions, Bose Active Sound Management uses proprietary signal processing algorithms to replace heavy, space-consuming parts, such as acoustic insulation, mass dampers, and active exhaust valves.
The Bose algorithm works with the vehicle’s sound system to control powertain sounds in the cabin. The system continuously receives information from the engine and, using this information, identifies undesirable engine noise. The system then generates an acoustically opposite signal that is reproduced by the audio system’s speakers. The acoustically opposite sounds cancel each other out, reducing much of the engine noise in the cabin. The system uses microphones in the cabin to monitor noise and make adjustments. It all happens continuously and automatically, for a consistently quieter ride.
Active Sound Management is already available in cars with Bose sound system hardware, including models from Buick, Cadillac, Chevrolet, and Infiniti. The Bose/NXP collaboration makes it possible to implement the technology in a wider range of cars, so consumers looking for a quieter ride will have more models to choose from.
The Bose/NXP offering adds the Active Sound Management software solution to the NXP integrated radio tuner SAF775x. The Bose software solution will operate in any vehicle using a head unit equipped with NXP’s SAF775x car radio IC, and any sound system that performs in the frequency range necessary for active noise cancellation.
The SAF775x is a one-chip integrated radio that combines a front-end receiver, a baseband, and audio signal processing onto a single IC. It’s equipped with a global single tuner for AM/FM radio reception, so it can be used anywhere in the world. NXP’s audio engineers have already done the work of optimization and integration, so using the SAF775x makes development easier, faster, and more customizable.
If you’d like to learn more about our collaboration with Bose, then come see us at CES (Booth CP9). We’ll be talking about quieter cars and, among other things, our connected solutions for home automation, mobile devices, and more. Visit our CES website for more information: http://www.nxp.com/events/ces2014/.
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