From Radio to Intelligence: How Modern Automotive Audio Systems Are Redefining the Driving Experience

1.Introduction
2.Core Architecture
3.Multi-dimensional Value
4.Bestar's Technological Empowerment
5.Futures
6.Conclusion

Introduction
What's there to sip, squirt and slant at in the auto audio world? The other car stereo's capabilities were in the past more limited than they are now. Just a pair of speakers and a car radio. Turn the dial, press the button of a station and drive! That was it.
It's quite a different scene in today's world. The stereo system in a modern car plays music, communicates with the phone, operates voice control functions, controls cabin noise and aids pedestrian safety notifications-all simultaneously. It's not just an entertainment enhancement anymore. It's an integral component of the driving experience.
It has been an opportunity and challenge for automotive engineers and suppliers. Setting up an audio system that works well while driving a car is difficult. There's always an odd amount of space for components, extreme lows and highs temperatures, and a lot of noise. Care must be taken to get the initiative right, and this calls for the very same specialised parts and know-how in engineering.

Core Architecture
An audio system consists of several components are linked together. All the parts have a function to perform and must function synchronously without any breaks.
1. Head Unit / In-car Infotainment 
Head unit = command center. It's the interface where the car driver can choose sources, set up its parameters and give it voice instructions. Although audio is a primary component of in-car infotainment, the technology is doing much more than that. All of this is handled via one interface, with navigation audio, integration with telephones, streaming, and real-time voice recognition all controlled by them.
Data is also sent downstream to the remainder of the signal path from the infotainment system. Everything else to the end of the unit is dependent on the outcome of the unit you will have.
2. Digital Signal Processing (DSP)
The audio signal to be played out of the in-car infotainment system is not easily playable at first. The DSP takes care of cleaning it all up. It makes tuning corrections for the unique characteristics of a particular cabin shape, adds equalisation, controls the spoken word relationship between the speaker and the speaker inputs and addresses unwanted noise from the recording environment or transmission noise.
The DSP in simple terms does what is supposed to do, to make audio sound like it is supposed to sound in a car.
3. Power Amplifiers
The output from the processer through the amplifier is sufficient to energise the speakers. With application in the automotive field, amplifiers must be very efficient at 12V, must be rugged for extreme temperatures and must give the same output level on all listening levels. In premium vehicles often you will find the multi-channel amplifiers with unique selectable speaker zones.
Speakers and Acoustic Components
It is from here that the signal turns sound. The most physical component of the system is the speakers. They have to work in a place that is constantly vibrating, wet and hot. This is well beyond the capabilities of standard consumer speakers.
Acoustic components for vehicles are not developed to the same standard. The materials and workmanship they employ resist car abuse, such as humidity exposure, high and low temperatures, and road vibration or years of heavy use. 
4. Microphones
The ears of the system are the microphone(s). The high sensitivity of the microphones allows voice control to be picked up, even in the presence of road noise, wind and music in the cabin. Clean pickup equates to fewer commands from robotics misheard, better call quality-which is important, for good reason, for both convenience and safety.

Multi-dimensional Value
Modern car stereos have multiple functions. The requirements for the hardware are different in each of them.
1. Sound Reproduction
On the basic level, customers demand good vehicle audio quality. Music, podcasts, navigation prompts and movie audio for the passengers in back must be clear, and have enough detail to be pleasant. Quality speakers and a well tuned system make a difference in the length of a trip.
2. Voice Communication
Almost all new cars come with hands-free calling and voice control. The microphone should be able to capture the driver's voice clearly and effectively without picking up the cabin noise for good performance. The system must also have voice cancellation, so that the far end caller will not hear their voice being echoed in the car speaker.
Bestar's microphones are designed for this kind of setting, directional pickup, low noise floor and good rejection of suppression of background noise.
3. Acoustic Comfort
The noise from the cabin is exhausting. All the noises of the engine, road, wind add to fatigue over a long period of time. Active noise cancellation (ANC) does just this. The front-end generates a real-time supplemental anti-noise signal in the cabin from the microphones that detect low frequency noise to be generated by the speaker to cancel it.
What this does end up creating is a cabin that is quieter, but still has the same amount of thermal insulation, without having to add more bulk. Today, many cars from the mid-range and high-level classes have active noise cancelation, and more technologies are coming along to provide even more effective noise cancellation. Bestar provides acoustic components which can be integrated to comply with the tight performance tolerances required by all of these speaker systems capable of embedding complex-and costly ANC technology.
4. External Safety Communication
EVs provide an additional acoustical challenge. For such an early step as cars powered by electric energy, EVs are almost silent, often going undetected by pedestrians when operating at low speeds which is a safety hazard.
Nowadays, major markets, like US, EU, China, and elsewhere, electric vehicles are required to use a replacement warning mechanism if they fell below a certain speed. These systems are called "Acoustic Vehicle Alerting Systems (AVAS)". The AVAS system should present sound in a predictable pattern in an upper and lower frequency range, with a specific volume, for pedestrians to be able to identify the vehicle based on sound only.
The designing of a good AVAS system is not a trivial task. All of this must be carefully engineered, including where the speaker will be mounted, profile of sound from the speaker, volume changes at various speeds and so forth. 

Bestar's Technological Empowerment
The correct acoustic design for the automotive application is an art and a science of its own. There are three key strengths that Bestar will leverage to face this challenge.
1. Customization for Every Platform
No two vehicle platforms are alike. The design and mounting of a speaker depends on the door cavity, the dimensions of the dashboard, the amount of trunk space and more. Bestar collaborates with automotive engineers at an early stage of design, in developing its acoustic components, which are sized and tuned to the given platform. It's not off the shelf it's application matched engineering.
2. Automotive Grade Reliability
The automotive supply chain is based on the qualification data. Purchasing customers must understand that car parts will last the entire vehicle's life expectancy if they are used in the field. Bestar submits components to rigorous automotive grade testing, including stress tests of high temperature storage, thermal cycling, humidity exposure, vibration and salt spray.
3. Engineering Support and Integration
Once you get the right acoustic component, deciding what to buy is not the end of it. Bestar's engineering team provides support for customers' circuit design reviews, acoustic simulation, and system-level integration. This type of in-person assistance accelerates timelines & minimizes “late stage redesigns”.

Futures
The automotive audio market is rapidly changing and there are several trends that will help guide these changes.
Immersive 3D Audio
Space audio formats are getting new traction in vehicles, because with such formats, the listener feels sound emanating from certain spots around and above him. A number of speakers placed around the cabin generate the 3D sound field. The processing requirement calls for a lot of effort and the component tolerances are too tight. In the future, the technology will become more common and will propel demands for accuracy acoustic components.
Implementation of Deep Learning Based Noise Reduction
Traditional active noise cancelation is suitable for "predictable" low-frequency noise. Deep learning models can be used for more intricate broadband/noises types (wind turbulence, road conditions and harmonics of highly vibrating engines). They are stored on vehicle equipment's DSP hardware, and adjust as the situation evolves. The components which contribute to the acoustics for these systems must have the same acoustics, and produce minimal noise.
Automotive Audio & Vehicle Sound Engineerings
AVAS will progress beyond just high-end vehicles to being available on entire vehicle lines, as EVs become increasingly prevalent. In addition to pedestrian warning, external speaker applications are very popular for the following acoustic applications such as parking guidance cues, charging status markers and brand identity sounds. Bestar's AVAS level external transducers are already geared for this increased responsibility.

Conclusion
Now sound is no longer just a by-product of a car. They are going to make a good portion of the vehicle's 'feel' to the rider and of how it 'feels' to the world around it, the in-car infotainment, active noise cancellation system, AVAS system, microphones and the speakers.
Constructing these systems to automotive requirements requires specially-developed components, extensive engineering co-ordination and a supplier who has both acoustics and the automotive supply chain knowledge.
Bestar has been developing acoustic components for automotive applications with just that in mind. From premium cabin audio, voice interaction, noise control, to electric vehicle safety, Bestar's solutions designed to perform, today and for generations to come.