Audi e-tron GT: interviews with the people behind its sound and production

As well as having the chance to test the Audi e-tron GT in its sportiest RS specification, the German brand also gave us the opportunity to speak to two people responsible for the German model.

One was Stefan Gsell, who led the creation of the e-tron GT’s driving sound and told us that “the real world inspires digital sounds”.

The other, Alexander Breuer, Production Director for the Audi e-tron GT, cannot help pointing out that “it is incredible to produce the e-tron GT and the R8 on the same assembly line”.

In this interview, they reveal more about their work and some of the details behind Audi’s new electric model.

Technology and nature working hand in hand

How do you create the sound for a sporting electric car?

Stefan Gsell (SG): The more we explored possible solutions, the more we realised that sounds drawn from nature could be better suited to accompany a journey in the e-tron GT.

The car has a very powerful design, and we wanted its sound to follow the same approach. We used a broad sound spectrum to cover the various driving situations, ensuring it was not overly prominent while remaining distinctive and emotive.

We reserved low frequencies for moments of sportier performance, while mid and high frequencies help signal the car’s presence in urban surroundings. This allows other road users, including pedestrians and cyclists, to be aware that the Audi e-tron GT is approaching.

Audi e-tron GT sound development

Was the work of researching acoustic frequencies more digital or analogue?

SG: We worked with tubes, fans and helicopter blades, achieving surprising results.

Very often, the least likely object produces the most suitable sound. However, unlike a single sound, a car has to sound continuous, so we ultimately developed our own software - because it did not exist, we had to create it.

We believe the final sound speaks 1,000 words. We used 32 tracks for recordings that we composed with synthesisers, musical instruments, tubes, etc.

In brief, how does the system work?

SG: A loudspeaker projects all sound outside the car in order to meet legal requirements - up to 20 km/h in Europe and 32 km/h in the United States. Dedicated acoustic models were developed for each market, in terms of both frequency and volume, even though the overall pattern is quite similar. Above 60 km/h, it can no longer be heard, not least because tyre noise from contact with the road surface and aerodynamic noise take over.

An optional sound package adds another exterior loudspeaker and two at the rear of the passenger compartment, creating a more immersive acoustic experience.

What was the greatest difficulty you encountered during this process?

SG: We did not want to overdo it by producing something that sounded too much like “science fiction”, and resisting that temptation was one of the biggest challenges.

It was also important to distinguish Audi’s sound from Porsche’s. We even preferred not to know what each team was doing, in order to avoid unwanted influences.

Is there only one sound, or can the driver select or download others?

SG: The driver can influence the sound by selecting the “Efficiency”, “Auto” or “Dynamic” driving mode, with a sound character that matches that mood and attitude, both inside and outside the car.

We could have offered the possibility of different sound types, but I think we made the best choice, also because a range of legal requirements must always be met.

Interestingly, the sound inside and outside the car is not always the same. Inside, it is heard only in “Dynamic” - not in “Comfort” or “Efficiency” - and, even then, it merely complements the sound generated outside.

People and machines on the production line

In summary, what are the stages involved in Audi e-tron GT production?

Alexander Breuer (AB): It all starts with body production at Böllinger Höfe. The body is then sent to Neckarsulm, only a few kilometres away, for painting, before returning to Böllinger Höfe for final assembly alongside the R8.

After all, these are the two most powerful series-production Audis ever made.

Audi e-tron GT and R8 assembly

What did you do differently to make this possible?

AB: Thanks to virtual testing, this was the Audi that reached series production fastest, as it enabled us to skip many physical tests involving real prototypes.

A dedicated assembly line was installed for this electric car. The body and chassis pass through the production line twice, in processes that are fully automated both inside and out.

The first pass is for fitting interior components, while the second handles exterior components. There are 10 robots and 32 tools, meaning every robot can carry out more than one task: during the first pass it may be welding, and on the second it may be securing a component.

Will robots replace people on the assembly lines of the future?

AB: The R8 has an aluminium and carbon-fibre-reinforced plastic space frame and is built almost entirely by hand, whereas the Audi e-tron GT features a structure made from several types of ultra-high-strength metal and is assembled almost entirely automatically.

Yet human expertise remains irreplaceable in some areas. Welding the B-pillar is very complex, which is why our specialist R8 craftspeople weld these aluminium components, drawing on all their years of experience.

Before the car goes to the paint station, there is an attachment-fitting area where elements such as doors, bumpers and the bonnet are installed. Once again, every surface must be 100% perfect, so the human eye and touch are vital.

In any case, this is an ultra-modern assembly operation that does away with traditional continuous lines. Instead, it uses a series of autonomous vehicles to transport parts and even bodies, delivering them to precisely the right place with great flexibility and efficiency.

But do you acknowledge the contribution of new technologies to manufacturing any modern car?

AB: Of course, digitalisation played a central role in this new assembly line. The assembly area was completely digitised in a computer programme, and even the production launch was studied entirely virtually, a first for Audi.

Another example is 3D printing: someone simply designs a part in the computer programme, sends it to the 3D team and, a few hours later, we have it in our hands ready to fit to the car.

Which of the two models takes longer to produce?
AB: The R8 takes a little longer because carbon-fibre components require extra time to install.