Audio in motion
Harman’s chief engineer of acoustics, arndt Hensgens, offers insight on the complex task of creating and tuning an audio system for the difficult environment of the car.
Harman needs to stay on the cutting edge of in-car audio technology. To help with this, the company has developed its own system to test in-car audio for better results at faster rates. Naturally, the process is extremely technology-reliant.
“It takes on average four years before a system is ready to be installed. We have very good relationships with the OEMS and work closely with the vehicle design team to provide a bespoke solution. We specify the position and space needed for the speakers, then when the first production cars are ready we start the tuning process—it can take months,” Hensgens says.
“At Harman we have created a system called Auravox that helps us rapidly and efficiently complete the first 80 per cent of the testing task. It was developed in-house and took a specialist team of Harman engineers five years—it’s extremely effective. Twenty-four microphones are used to measure the sound within the interior of the car, sending this information to the Auravox software that automatically evaluates hundreds of parameters and independently generates the appropriate filters, corrects speaker delay differences, and sets optimum volume levels of individual channels.”
He explains that most other audio manufacturers would be happy with the results at this stage, but Harman’s engineers also look to get that last 20 per cent right by finetune the system to match the audio brand’s benchmarked standard.
“It’s what Harman has been pioneering for decades: it makes a real difference and is why audiophiles like our products,” surfaces. The speed, road surface, number of passengers, the roof being up or down, even if the car is petrol or diesel affects the audio. It all needs to be considered and evaluated.
Naturally, the sort of music being tested also needs to be considered. After all, gearing in-car audio towards a sound that suits classical music may not be very well appreciated by buyers who’d prefer to listen to Dr Dre.
“We use a range of music and each engineer has their preferences and ‘go to’ tracks. I’ll play classical music followed by heavy metal bands, jazz and then pop—you need to really get a feel for the system across all genres. We also have to consider the type of music a person buying that particular car would listen to,” Hensgens says.
“In the final weeks before the car goes into production we make the final tweaks to the system, and only then when we’re happy that the audio is at its finest will the system be signed off for production.”