## Software-Defined Audio Architecture Cuts Cost, Weight, and Complexity for Automakers
**Better sound through software.**
Since the dawn of high-fidelity audio, size and weight have been conflated with sound quality. Bigger, heavier speakers are considered better, and if you come across a car with a properly banging system, you expect its trunk to be full of giant, glowing amps, crossovers, and all the other ancillary components a best-in-class system needs.
That’s fine when you’re talking about aftermarket audio, when the intent is as much about the show as it is about the sound. However, when you’re designing a new system for a new car, the goal is to minimize weight and volume while maximizing sound performance. Huge, heavy components are a detriment. That’s doubly true when that new car is an EV and you need to factor range and power consumption into the mix.
Software, as it turns out, might just provide the answer. We’ve already seen how software-defined vehicles can change and evolve, simplifying and minimizing onboard hardware to make cars leaner and meaner. Now, thanks to some new technology from QNX, they can sound better, too.
### Pumping Up the Volume
Numerous factors go into creating a sound system designed for a modern car. The quality of the speakers is, of course, key, but so too is their placement. Interior designers and audio engineers have long struggled with conflicting goals: creating the greatest interior volume with the most striking design while also making room for the dozen or more woofers, tweeters, and mids that a modern system requires.
But you’re not done yet. More and better speakers need more and better amplifiers to drive them. Amplifiers take the raw audio signals, shape them sonically, and give them the power required to fill the cabin.
Even getting that raw audio has become more complicated of late, with in-car audio systems increasingly supporting advanced digital encodings. Want to groove out to a Dolby Atmos stream? Your car needs to do some work to convert the ones and zeros coming from your streaming service of choice, and turn them into something your ears can make sense of. After all, you want your music to sound like music, not just noise.
Now add the complexity of needing to manage all the other types of signals that you hear in the car in addition to music — Bluetooth audio for voice, synthetic propulsion sounds for EVs, chimes and ADAS alerts — and it quickly becomes apparent that there’s a lot going on in modern automotive amplifiers.
This complicated mix of signals is traditionally managed by a piece of hardware inside an audio amplifier called a digital signal processor, or DSP. DSPs come from various manufacturers with varying degrees of quality and compatibility with modern sources, plus additional features like equalization, compression, filtering and even built-in room correction. Just about every car on the road today has an amp with a DSP capable of handling digital streams from your mobile device. In contrast, only more recent amps have DSPs advanced enough to handle something like Dolby Atmos streams that services like Apple Music can provide.
A DSP capable of doing that is more complicated, which of course means it’ll likewise be larger, heavier, costlier, and more power-hungry. Those are all bad things in modern car design. QNX’s latest extension to the software-defined vehicle paradigm is providing another alternative.
### SDV Refresher
At a high level, the software-defined vehicle is any car in which functions traditionally handled by discrete hardware components are now managed in software. For example, once upon a time, simple hardware relays managed the rate at which a turn signal blinked. This was the clicking sound you heard from under the dashboard. Want to change the way the turn signal worked? You need to change that relay. In a modern car, though, it’s code and microprocessors that switch those lights on and off. And that clicking sound? It’s being generated by software these days.
You can extend the same concept to everything from fuel injection to stability control, with intelligent software taking control of more and more aspects of a car’s behavior. This has the primary benefit of cars that can get far smarter, like heated seats that turn themselves on when it’s cold or a hands-free driving system that learns new roads over time.
But these systems also serve to remove discrete pieces of hardware from the car, reducing weight, power consumption, and cost. And that’s what QNX Sound promises to do for next-gen audio systems.
### Coded Beats
QNX Sound is, at its core, a software-defined layer that effectively serves as a high-end sound system. It’s a new level of hardware virtualization applied to the world of hi-fi. Instead of your car having an amplifier with its own dedicated audio DSPs, a car running QNX Sound instead takes that raw, digital sound input and pumps it into a powerful system-on-a-chip, or SoC, which, in a software-defined vehicle, is responsible for numerous other tasks ranging from body and lighting control all the way to digital cockpit displays and autonomous driving.
Eliminating amp-based DSPs means the car can use simpler, smaller, lighter, and cheaper amplifiers. QNX estimates that, by switching to QNX Sound, manufacturers could use up to 44 percent fewer components in their audio amplifiers, equating to a 28 percent weight savings. That could deliver a cost savings of up to $98 per vehicle, according to a study from Munro & Associates.
Despite that significant reduction in dedicated hardware, the additional load placed on the car’s SoC-based central processor is minimal. In its testing, QNX found that running a 23-speaker Dolby Atmos stream required only 2 percent of a modern SoC’s processing capability.
That’s a minimal increase, especially considering that the SoC’s volume, power consumption, and cooling needs have already been accounted for in the car’s design. All this combined means fewer compromises when it comes to the all-important interior design.
### Evolving Standards
Another key aspect of this is the ability to grow and evolve. In the past, adding support for a new audio encoding format would require dedicated hardware upgrades, the sort of attention that cars on the road rarely receive.
Moving a car’s audio system into the software-defined vehicle world means upgrades and extensions would be relatively trivial. Everything from new codecs to personalized audio environments to advanced audio effects could be just a download away, versus a car whose audio capabilities are impenetrably locked from the moment it’s built.
This also opens the door to more advanced branded experiences. In the past, auto manufacturers have partnered with various recognizable audio companies, placing a logo here or there in the interior to signify a certain standard of tuning. Now, both the car companies and the audio partners would have a far greater range of control of the entire experience, able to tune and tweak everything through software deep into the development cycle of the vehicle, and even beyond the day it rolls off the new-car lot.
QNX has already partnered with Dolby to integrate Dolby Atmos as well as with Dirac, which provides advanced signal processing, including room correction and immersive sound experiences. This is the kind of tech that could make tomorrow’s cars sound better than ever, even without a trunk full of amps.
