Car stuff (public number: chedongxi)
Author | Haohan
Edited by | Xiaohan
In the car, not only do you listen to a "ring", The Bose car audio artifact is coming!
With the rapid development of in-vehicle audio and the continuous improvement of consumer demand for in-car listening, the acoustic experience in the car has become an important indicator for consumers when choosing a car to buy a car, and major audio brands are also "rolling in" in terms of sound effects, sound quality, and sense of atmosphere in the car.
At present, smart electric vehicles are developing rapidly and gradually popularizing, and the number one enemy of the listening environment in traditional fuel vehicles - engine noise has been solved from the root. The various noises from the road surface have been replaced by them, becoming the biggest enemy of the listening environment in electric vehicles, and have also become the research and development topics of major audio brands.
Bose took the lead in bringing active sound management technology, including engine harmonic noise reduction technology, engine harmonic enhancement technology, active road noise reduction technology and other four technologies, which can effectively improve the acoustic performance in the car.
In Bose's active sound management technology, active road noise reduction technology is the biggest nemesis of road noise, which can measure vibration from the road surface and tires through acceleration sensors, and use Bose's noise reduction algorithm to generate inverted phase acoustic signals to achieve noise reduction.
In addition, bose active sound management technology also includes electric vehicle engine sound simulation technology, which can provide auditory driving enjoyment for electric vehicle occupants and add a flexible to the quiet cockpit after noise reduction.
As the world's top audio and acoustic system developer, Bose is using industry-leading audio technology to continuously optimize the cabin acoustic experience and provide more possibilities for in-car audio scenes.
First, Bose cabin sound management four skills hearing experience to the next level
I believe that most people know the Bose brand, starting from noise-canceling headphones. Bose's place in consumer-grade active noise-cancelling headphones is self-evident, and its noise-cancelling products also provide us with countless quiet voyages, quiet work and calm thinking.
However, in fact, Bose also has a 20-year history of research and development in the automotive field of noise reduction, and its engine harmonic noise reduction technology was installed on the Cadillac Cared model of the year as early as 2010.
▲ 2010 Cadillac Careyd
If you look at the development of Bose in automotive noise reduction technology, Bose first introduced engine harmonic noise reduction technology (EHC), then engine harmonic enhancement technology (EHE), then QuietComfort active road noise reduction technology (RNC), and finally electric vehicle engine acoustic simulation technology (EVSE).
These four technologies make up Bose active sound management technology.
Specifically, Engine Harmonic Noise Reduction (EHC) and QuietComfort Active Road Noise Reduction (RNC) are primarily responsible for noise reduction, with the former attenuating harmonic noise from the engine and drivetrain, while the latter is responsible for reducing noise transmitted from the road to the cabin.
These two technologies can improve the noise problem in the car without adding more sound insulation materials, breaking through the limitations of traditional mechanical solutions such as increased vehicle weight, reduced handling and reduced fuel efficiency.
▲Engine harmonic noise reduction technology
The engine harmonic enhancement technology (EHE) and the electric vehicle engine acoustic simulation technology (EVSE) are mainly responsible for sound reinforcement technology, the former can improve the engine sound according to the different needs of different car manufacturers, and can greatly shorten the time for car companies to adjust the engine sound.
After the electric vehicle has a simulated engine sound, the electric vehicle can also have a rich driving experience, which satisfies the "nostalgia" of the electric vehicle owner for the sound wave of the fuel vehicle, and adds a pleasure to the driving.
In addition, compared to other in-vehicle passive sound solutions, Bose active sound management technology can automatically adapt to different road surfaces, tires and various variables of the vehicle's characteristics, maintaining adaptability and effectiveness throughout the life of the vehicle, while other in-vehicle passive sound solutions may not be able to adapt to changes in the road or the vehicle itself.
The difference between the two can be simply seen as the difference between "adaptive" and "disposable".
For car companies, Bose active sound management technology does not pick models, can cover multiple levels of different models, and can be used with different levels of audio systems, so that the quiet car space and surging car sound wave is no longer only the standard of high-end models, can really "fly into the homes of ordinary people." ”
In addition to Bose's active sound management technology, Bose has always attached great importance to the automotive business.
Che Dong learned that the current Bose automotive audio technology mainly includes active sound management technology, sound signal guidance technology, audio technology, voice technology, etc., and Bose has cooperated with Porsche, Cadillac, Infiniti, Hongqi, Lynk & Co and other domestic and foreign head car companies, and its technology and products have been installed on more than 100 models.
Second, headphone noise reduction is only a small CASE in-car noise reduction is hard power
Bose is a good at noise-canceling headphones, and the noise reduction in the car is just as good.
Like the principle of noise-canceling headphones, the principle of noise reduction in the car is also to achieve noise reduction by analyzing ambient noise and then using speakers to generate inverted phase acoustic signals. However, the similarity between the above two is only in principle, because the noise reduction problem to be solved in the car is far more complicated than the noise reduction headphones.
Generally speaking, if the noise entering the car is classified according to the source of sound, it can be roughly divided into three categories, the first is the noise of the power system, including the noise of the engine, the gearbox, and the exhaust system; the second is the noise of the road noise, which is transmitted by the vibration of the tires and chassis caused by the undulation of the road surface; the third is the wind noise, which is caused by aerodynamics during driving.
In addition, because the position of the driver's ear and the speaker in the car cannot be maintained in a relatively fixed position, it is necessary to form a larger Quiet Zone (quiet area) centered on the seat headrest to cover the relative changes in the position of various human ears in the car.
Xu Xu, head of engineering in China of Bose's Automotive Systems Department, said that if the size of a golf ball is used to describe the Quiet Zone (quiet area) of noise-canceling headphones, then the Quiet Zone (quiet area) in the car must be at least 2 to 3 basketballs as large.
The larger Quiet Zone means that the algorithm needs more computation, and it needs to be better matched from the human ear to the microphone to the speakers in the car, so the difficulty of achieving noise reduction in the car is also increased.
For cars, the biggest sources of noise in the car are engine noise and road noise. In Bose active sound management technology, engine harmonic noise reduction technology (EHC) and QuietComfort active road noise reduction technology are the biggest "nemesis" of engine noise and road noise.
Among them, engine harmonic noise reduction technology (EHC) can use the engine-related information provided by the automotive CAN bus to continuously monitor and measure the harmonic noise of the narrowband engine and drivetrain by arranging microphones in the car, using proprietary algorithms to find specific harmonics, and counteracting harmonic noise by generating inverted sound signals.
▲The working principle of engine harmonic noise reduction technology (EHC).
The QuietComfort active road noise reduction technology is to detect the vibration signal through the four acceleration sensors distributed on the four suspensions of the vehicle before the noise generated by the chassis vibration enters the cabin, and then analyze it through Bose's noise reduction algorithm, so that the audio system in the car emits an inverted sound signal and reduces the low-frequency noise heard by the driver and passengers.
▲The working principle of QuietComfort active road noise reduction technology
For the in-vehicle noise reduction system, the noise reduction algorithm is the first technical ability. "Acceleration sensors can be bought from the market, and noise reduction algorithms can represent strength." Xu Xu, head of engineering in China of Bose's automotive systems department, told the car something.
Compared with other brands of the same type of technology, the Bose noise reduction algorithm can cope with a wider noise frequency and a greater reduction, which can cover a wide range of application scenarios and bring consumers a better noise reduction experience.
Specifically, QuietComfort's active road noise reduction technology can reduce road noise by an average of 3 to 6 decibels in the operating frequency range, and can reach 10 to 15 decibels at certain frequencies. From an energy point of view, it can reduce half of the noise energy in the operating frequency range.
In the past, most of the luxury cars priced at hundreds of thousands or even millions were passively noise-reduced in the cabin through a large number of mechanical means such as soundproof cotton and double-layer rubberized glass. With bose's two in-car noise reduction technologies, the driver and passenger can clearly feel the difference between opening and closing noise reduction, which can make models priced at more than 100,000 people can also have NVH performance comparable to luxury cars.
Third, whether it is a gas car or a tram, it can make you listen more pleasantly
Of course, noise reduction in the car is not everyone's just need, and it is indispensable to the surging engine sound.
In this regard, Bose active sound management technology also has two major "magic weapons", namely engine harmonic enhancement technology (EHE) and electric vehicle engine acoustic simulation technology (EVSE). In other words, whether it is a gas car or a tram, Bose can make the "real and false" sound of the vehicle sound better.
First of all, for fuel vehicles, with the increasingly strict environmental protection emission regulations in many countries, small displacement, small cylinder number, and engine with turbo has become the standard configuration of fuel vehicles now, more and more car companies will use the 2.0T four-cylinder engine as the main sales configuration of their models, and the 3.0T six-cylinder engine has begun to become the exclusive of high-end cars, such as V8, V10 and other large-displacement engines have become luxury goods, only a few people have.
▲Porsche V8 engine
Although small displacement engines are matched with turbine and hybrid systems, their power can reach the level of large displacement engines. However, the sound of the small displacement engine is still not comparable to the large-displacement self-priming engine due to the shortcomings of the number of cylinders and displacement, which is also one of the most criticized problems.
Bose's Engine Harmonic Enhancement Technology (EHE) can use the car's audio system and sensors to amplify the engine harmonic sound and other sounds in specific frequency bands, thereby optimizing the drivetrain sound inside the cockpit, and achieving the ideal sound effect of the car manufacturer under the premise of meeting emission regulations, bringing surging engine sound to consumers. And the technology is only for the interior environment of the car, which can solve the problem of disturbing the people due to the excessive sound of the vehicle from the source.
In addition, for automakers, engine harmonic enhancement technology can also greatly shorten the time to tune the sound of the car engine and better display the DNA of the engine sound of each brand.
It is understood that in the past, when car companies adjusted the sound of vehicle engines, they usually needed to continuously adjust the parameters such as the volume of some chambers in the exhaust system, and then match the entire exhaust system and power system. In this way, the cycle of tuning the sound of a car's engine will be very long.
Bose's Engine Harmonic Enhancement (EHE) technology allows engineers to more intuitively and quickly adjust the car's engine sound. Xu Xu, head of engineering in China of Bose's Automotive Systems Department, told Che Dong: "Most car companies can complete the tuning of the sound of the vehicle engine in a week, and if the mode is more complicated, it may take two weeks." ”
▲The working principle of engine harmonic enhancement technology (EHE).
If the engine sound of small-displacement gasoline vehicles can also be enhanced, then electric vehicles can only rely on simulation if they want to have engine sound.
Bose's Electric Vehicle Engine Acoustic Simulation Technology (EVSE) analyzes vehicle data and applies Bose's proprietary algorithms to generate simulated engine sounds that can be dynamically adjusted.
In this set of techniques, algorithms are still Bose's biggest strength. The vehicle's amplifier system can communicate with the vehicle in real time, obtain the vehicle's real-time "electric gate" position, wheel speed and motor speed and other information, and optimize the algorithm based on these data, so that the simulated engine sound can be played out more naturally.
For example, when you step on the electric door deeper and harder, the sound of the vehicle will be more intense.
▲The working principle of electric vehicle engine acoustic simulation technology (EVSE).
In general, engine harmonic enhancement technology (EHE) and electric vehicle engine acoustic simulation technology (EVSE) are in the face of increasingly stringent environmental emission regulations, as far as possible to bring a better sound experience to fuel models and electric models, enriching driving pleasure.
Fourth, in-car intelligent audio is a new battlefield Bose has taken a step ahead
If you trace the origin of the car and audio, from the earliest installation of radios on the car, to the rich audio system on the vehicle now, it can be said that the car audio has accompanied the continuous development of the automobile industry.
In the past, major car companies and audio brands competed in the sound experience in the car, such as sound quality, power, sound insulation materials and other parameters, and in the future era of intelligent electric vehicles, active sound management technology will become one of the important criteria for judging whether the car is intelligent.
In the 2018 IHS Markit Consumer Survey on Automotive Technology, it invited more than 1,000 car owners to give their opinions on the importance of 14 advanced car audio features, which were divided into three opinion levels, namely important, indifferent and unimportant.
▲IHS car audio survey results
Among the car owners surveyed globally, it is generally believed that the three most important items in advanced car audio are excellent sound quality, surround sound and active noise reduction technology, of which active noise reduction technology is more than 56% of the surveyed car owners think it is important, and its importance is consistent with surround sound, which belongs to the second place; if only focus on Chinese car owners, then nearly 80% of the surveyed car owners think that active noise reduction technology is important, and only 8% of the surveyed owners think it is not important.
In advanced car audio, the importance of sound quality and surround sound is of course needless to say, which can be regarded as the "basic skill" of major car audio manufacturers, while active noise reduction technology is more like bose's "unique skill". Judging from the above data, the importance of the vehicle's active noise reduction technology has far exceeded the power, volume, 3D sound and other configurations of the audio.
Moreover, the use of active noise reduction to solve the problem of noise in the car, because the use of sound insulation materials can be reduced, then the endurance level of the vehicle can be improved to a certain extent, which is more in line with the future development trend of electric vehicles.
At present, in addition to Bose, many domestic and foreign audio manufacturers are also actively developing in-car noise reduction systems, and have gradually begun to test and prepare before mass production on the car.
Compared with other competitors, Bose has already mass-produced EHC engine harmonic noise reduction technology as early as 2010. In The QuietComfort active road noise reduction technology (RNC), Bose relies on many years of engineering experience in the field of noise reduction and the advantages of leading software algorithms, which will gradually achieve mass production in the next few years.
With the addition of QuietComfort's active road noise reduction technology, Bose's active sound management technology will be more perfect, and bose's golden sign of noise reduction will continue to shine in the automotive industry.
In addition to noise reduction technology, Bose also has a corresponding layout in terms of voice technology, assisted driving, etc. With 40 years of R&D experience and a number of technological innovations, Bose has clearly achieved a leading position in this new battlefield, which will also bring new growth opportunities for Bose in the era of smart electric vehicles.