An SUV prototype in designer camouflage dress that moves virtually silently through its environment is the perfect stage for a sophisticated audio system. That environment was Copenhagen where I recently had the opportunity to ride in the long-awaited Audi e-tron electric SUV concept car.
Before taking to the streets we were given a virtual demonstration of what to expect using the interactive 3D wireframe model and VR glasses whose head-tracking feature allowed us to click on specific areas and call up more detailed information. This simulation enabled me to ‘examine’ the e-tron’s sound system from all sides.
Once again Audi uses the 3D sound system jointly developed with Bang & Olufsen and Fraunhofer. Enhanced by the Fraunhofer Symphoria algorithm, this system made its debut in the current Audi A4 in 2016 and has been rolled out in subsequent new models like the A8, A7 Sportback, and A6. I had the opportunity to experience this essentially touch screen-based concept on the road in Copenhagen, albeit only from the passenger seat.
For Audi, as with all the major manufacturers, e-mobility in production form is a journey into uncharted waters. The game plan is to maintain interest in the Audi e-tron by feeding the media with impressions of different aspects of the car right up to the actual driving event at the end of the year.
The Copenhagen ride experience revolved around the e-tron’s cabin where the sound system plays a major role. The theme here is not just entertainment, but the entire staging of electric driving. While “silent electric locomotion” may be the topic at hand the fact is that the mix of engine noise and the environment whizzing past stimulates this petrolhead, and is also in the DNA of every car enthusiast.
Electric cars we have driven in the past have always seemed at odds with their lack of engine noise because the rolling noise of tyres on tarmac becomes all the more heightened. It is thus pleasing to note that Audi has gone to great lengths to banish these intrusive sounds from the e-tron cabin.
The electric motor transmission unit mounted in the centre of the multi-link rear axle features elastic mounts to reduce mechanical vibrations, while the subframe in turn is decoupled from the body with bespoke rubber bushes. Similar isolation measures have been taken with the electric motor that drives the front axle.
It all seems to work as advertised and the Audi e-tron starts soundlessly and remains extremely quiet even under the full acceleration sprint that Rupert Spielvogel, the man responsible for user interface, was happy to demonstrate.
Instead of the “electric-tram-at-speed” sound made by the Tesla and others, the e-tron only generates a slight whistle in the distance, even under full power. The counterpoint is of course the external noise required to warn errant pedestrians from crossing in front of an electric car. Audi say they have this to hand but it was not yet installed in this prototype.
The Bang & Olufsen premium 3D sound system in the Audi e-tron provides the really big sound show, and its 16 speakers no longer have to compete with a growling internal combustion engine. In fact they do not have to fight rolling noise either and our tour through Copenhagen showed how effectively the extensive acoustic insulation of the lined wheel arches filters this out.
What remains is pure audio akin to what you might experience at home in your living room; or perhaps better. The sound from the elevated 3D speakers in the A-pillars and centre-speaker reflecting off the windscreen significantly increases the sound stage in the vertical plane. Even applause during live recordings sounds more authentic than usual and the 3D sound effect can be tailored to individual preferences in three steps. Meanwhile, a virtual slider on the 7-inch OLED display of the Touch-MMI allows the user to continuously adjust the surround effect.
The symphonic algorithm developed by Audi in cooperation with the Fraunhofer Institute in Erlangen calculates the information with semantic abilities to distinguish between direct sound and spatial components from stereo or 5.1 recordings in the third dimension and prepares them for the 3D speakers.
The low-midrange drivers of the 705-watt B&O system are housed in their own enclosures and integrated into the front doors. This creates the best conditions for controlling bass frequencies while shielding the output of the speakers from the environment. Incidentally this also keeps voices inside the cabin, and thus private when you are using the speakers during a hands-free phone conversation.
As you would expect in an electric car there is no additional luggage space in front, only a flat shelf that houses the charging cables. Thanks to double-sided, stylishly implemented charging bays, the Audi e-tron is also set to gain a head start with technology in the race for a place at the charging station. Here the 150kW fast charger takes 30 minutes to deliver an 80-percent charge that will take you 400km.
The deep bass frequencies come from a bespoke 200mm diameter subwoofer in the boot. Designed to save space this unit features double voice coils in a narrow and rugged integrated package at the back of the load compartment floor.
While bass frequencies are omnidirectional and more tolerant of background noise there was no question that the absence of road noise allowed our ears to pick up the nuances that this high quality powered sub-woofer was able to portray. However, this ideal environment also mercilessly uncovered the fact that not all low frequencies are recorded with the same quality.