As electric vehicle (EV) technology continues to evolve, it brings new challenges for designers to overcome. One such challenge is the ambient noise created when driving, which is different in some ways from that of an internal combustion vehicle and can affect the performance of an EV’s in-cabin audio system. British audio technology company and automotive supplier Meridian Audio believes it has solved this challenge, and Korean automaker Kia Motors is putting that solution into practice.

The new 2024 Kia EV9 luxury electric SUV is one of the first vehicles to be specified with a sound system designed and tuned specifically for the unique audio characteristics of a pure EV. Following its extensive research into the requirements for delivering an immersive acoustic experience in EVs, Meridian’s 14-speaker system employs a suite of proprietary DSP (digital signal processing) technologies optimized for the surprisingly challenging acoustic environment.

The EV9 is the third Kia vehicle to feature Meridian technology, following the K8 luxury sports sedan and the EV6 premium electric crossover. With a starting price of $73,900 for the EV9’s top trim level, the GT-Line, Kia has positioned the EV9 as a direct competitor with established luxury vehicle offerings.

“Based on the success of our current collaborations, Kia challenged us to engineer an immersive surround sound system that will enhance the luxury experience for all occupants,” said Meridian Audio Chief Executive, John Buchanan. “Kia wanted to retain the design purity of the EV9 concept car, so we worked closely with their design team from an early stage to ensure this could be delivered without affecting audio quality, cost, or manufacturability.”

“The challenge with delivering a fantastic audio experience in an EV isn’t the level of the background noise, it’s the complexity of noise sources and their frequency profiles,” said Buchanan. “These are typically at significantly higher frequencies than in a combustion vehicle, which can affect our ability to perceive the position of sounds, and they can be more random, which makes the acoustic environment more difficult to manage with active noise cancelation.”

The solution, according to Buchanan, is to move the focus from hardware to software, managing the acoustic environment through Meridian’s proprietary DSP algorithms and then overlaying further DSP technologies to tailor the sound to the requirements of the specific vehicle and the tastes and activities of the vehicle occupants. Meridian says it typically re-invests around 15% of revenue in research, with a significant proportion focused on software for optimizing and tailoring the audio signal in a listening environment.

Among the suite of DSP technologies for the EV9 is Meridian RE-Q, which is said to intelligently and discreetly optimize the audio system to the precise acoustics of the vehicle cabin. Meridian Digital Precision maximizes the signal-to-noise ratio, preserving the natural rhythm of the performance. Meridian Horizon, an upmixing technology, provides multi-channel audio from both two-channel stereo and native 5.1 content, seamlessly delivering a surround-sound experience complete with center image and ambiance level controls for the user. Meridian’s lntelli-Q Data-Driven Equalization psycho-acoustically optimizes audio playback by responding to the changing nature of the in-car acoustic environment as vehicle speed changes.

“Intelli-Q also allows us to manage the unique acoustic inputs of an electric vehicle,” said Buchanan. “Unlike earlier systems that simply increase the volume as a response to background noise, Meridian’s proprietary technology reacts to the profile of the background noise, for example increasing the low and mid ranges as tire noise becomes more prominent with speed or rougher road textures. This gives us a managed acoustic environment onto which we can build an immersive, captivating listening experience.”

An open-air connected subwoofer (OCS) was selected for the EV9 as it removes the need for a large box enclosure. Conventional enclosures require substantial packaging volume and can create resonances and rattles. They also limit frequency extension and timing. The combination of the OCS and Meridian’s proprietary tuning techniques has eliminated these issues, providing exceptional bass performance that is fast, precise, and deep for all seating positions.

Kia’s relationship with Meridian has also benefited from the audio tech company’s approach to sourcing, which allows a hardware-independent route to flexible, upgradeable in-car audio platforms.

“By working closely with Mobis, Kia’s chosen hardware first tier, we were able to support their desire to improve manufacturability, packaging, and costs,” said Buchanan.

The Kia EV9, introduced at the 2021 Los Angeles Auto Show, is a midsize three-row SUV. It seats up to seven passengers and comes in two-wheel-drive variants that offer 160 kW and 258 lb·ft (350 N·m), as well as twin-motor all-wheel drive versions with up to 283 kW and 515 lb·ft (698 N·m) for a 0-60 mph (0-97 km/h) time of about 5 s. The EV9 can tow up to 5000 lb (2268 kg).

The 2024 model is already in production in Korea but the EV9 will eventually be produced at Kia’s plant in West Point, GA, starting later this year.