Blog: How to speed up development of car audio systems

Comparing today’s car audio systems to those of 10 years ago is like comparing an iPad to a 1980s TV: They perform some of the same functions, but the modern product is vastly more capable and complex. Not only does a modern car audio system play radio, it must accommodate multiple sources (Bluetooth, USB sticks, analog inputs and CDs), and separate the driver’s voice from road and engine noise for phone calls and voice commands. It may have to generate warning sounds for pedestrians, and synthesize engine sounds to enhance the driving experience.

Wonderful as these new systems are for drivers and passengers, they’ve made work more complicated for audio engineers. It’s no longer sufficient merely to build and tune a speaker system. Now automotive audio engineers may have to optimize a microphone array, design warning tones and other sounds to be generated by the system, interface with smartphones and Internet connections within the car, and provide for future upgrades.

However, the budget and time allotted for development of these systems has not necessarily expanded as quickly as their complexity. And according to John Whitecar, who served as Sr. Manager of Wireless Engineering for Tesla before he became COO of DSP Concepts last year, the development methods for automotive audio engineers remain surprisingly manual and labor-intensive.

“In a typical automotive audio development environment, the engineers design most of the audio processing from scratch,” Whitecar says. “Normally, an audio engineer starts by designing processing blocks in Matlab, Then another engineer, one whose skills are focused on coding, converts those Matlab blocks into C code. Another engineer then modifies the C code to optimize it for the DSP or SoC that will be used, and then the code needs to be debugged to ensure it runs without glitches.

“I used to have to do a lot of that work, so I’m very sensitive to the demands it places on the engineering team,” he adds.

As a Tesla employee, Whitecar found the solutions to these problems in DSP Concepts’ Audio Weaver, a modular audio signal processing programming environment that runs on all major DSP platforms as well as on many SoCs. His enthusiasm for Audio Weaver led him to join DSP Concepts in 2017.

“With Audio Weaver running on your platform, configuring an audio signal processing chain is quick and interactive,” he says. “There’s no need to write code. It has 400 functional processing blocks already built in, and I can just pull whichever blocks I need off the sidebar and drag them onto the screen, then connect then onscreen. If I need 10 more bands of EQ, I just get it. Most automotive audio engineers are stuck with a fixed EQ design that gives them a certain amount of functionality, but may not have exactly what they need. Or they’re stuck using a certain type of compressor rather than the one that’s optimal for their application.”

Most consumers might think of these kinds of features as exclusive to luxury cars. But according to Whitecar, there’s no reason why drivers of more affordable vehicles can’t enjoy similar luxuries. “Audio Weaver is a bridge to bring more advanced features into affordable vehicles. Once Audio Weaver is running, the designers can easily add whatever features the hardware will support.

“With Audio Weaver, you can do sophisticated audio processing on a small, low-cost processor such as a Cortex M4,” he continues. “You can use a $1.50 part to bring some very nice audio into an inexpensive vehicle. We’re seeing interest now among Chinese manufacturers, who are trying to create very affordable cars that still have nice luxuries, like a good sound system. Audio Weaver lets them create and innovate without having to worry how the processors they’re using will accommodate the features they’re adding. Once the systems are designed, they’re done.”