A lot has happened behind the scenes at Sennheiser in recent years. The consumer audio division with hi-fi headphones such as the Momentum True Wireless 3 reviewed by STEREO GUIDE has been sold along with the factories. The professional audio division with microphones will remain at the Wedemark site near Hanover. This is also where Sennheiser Mobility presented the first four-wheeled Sennheiser sound systems to a small group of international trade journalists. They can be found in some Cupra and Morgan cars. However, the special feature behind this is just as surprising as the fact that the car hi-fi systems are not consumer audio, but are assigned to the professional sector. Sennheiser does not supply the hardware, i.e. loudspeakers or amplifiers. The Hanover-based company concentrates entirely on the software.
However, this is plausible when you consider that even the big brands, from Burmester to Bowers & Wilkins, usually rely on speaker chassis from suppliers and concentrate on tuning. Burmester, for example, has its own garages in Berlin with all kinds of measuring equipment to work on secret prototypes. Harman has a whole block of garages in Garching near Munich to work on Audi and BMW vehicles. As far as these departments are concerned, there was nothing to see during our visit to the company headquarters in Wedemarrk near Hanover. Instead, we were able to get an idea of the complex production of microphones for stage, radio and TV.
Brit for fun
We were able to listen to the cars on which Sennheiser was actively tuning the system, as well as the cars on which Sennheiser is testing new technologies, in peace and quiet under canopies. That says a lot about the car audio sound system, but unfortunately not everything. This quickly became clear with the first car I listened to: a Morgan Plus Four – a classic-looking two-seater roadster with a post-war concept and a modern 2-liter four-cylinder BMW turbo engine under the two-piece hood.
An acquaintance owns one in the correct color British Racing Green and is happy about the driving pleasure. But because he wasn’t happy with the system, I had a listen to the previous sound system. It really wasn’t great, even when it came to the type, number and installation positions of the individual speakers. So I was all the more interested in what Sennheiser could tease out of the extremely purist sports car from England on new terrain, apart from the drivetrain with its ultra-modern ZF-8HP eight-speed automatic transmission.
I was impressed by the result. I really can’t say that I haven’t heard better systems in a car. And the three Cupras I listened to afterwards were also absolutely on a higher level. But why I was particularly impressed by the Sennheiser statement in the Morgan Plus Four: The car, which weighs just over a ton, is about as suitable for hi-fi music playback as a Ferrari GTO for a family outing, with its lack of insulation and its very open cockpit, even by conventional convertible standards. Incidentally, my esteemed colleague from Autoflotte has written an apt review of the Plus Four on their website – albeit without Sennheiser on board at the time.
The fantastic Four
With this in mind, I found the result in the Plus Four very impressive. Firstly, the Sennheiser system succeeded in delivering a broadband and balanced reproduction in the British roadster – with a comparatively large stage and an immersive sound experience. Even the reproduction of the sound in front of the two box seats was relatively good. Secondly, and roadster purists are likely to appreciate this even more, the spartan look of the luxury toy car was retained.
The Sennheiser experts achieved this by using exciters on the left and right of the dashboard to support the two full-range speakers in the low-slung doors. A total of 8 loudspeakers or actuators (they come from the neighborhood of Continental and are used to excite the cockpit panels and seats) provide a proper bath in sound. Because there was no room for a subwoofer in the lightweight body, which was cut particularly tightly according to a decades-old concept, Sennheiser resorted to a trick.
The bass was based on two actuators and two woofers under the two seats. The perceived bass was much higher than the low-frequency air vibrations reaching the ear due to the transmission of structure-borne sound to the popometer, which is responsible for the necessary sensitivity in sports cars when cornering and distinguishes the average Joe from Walter Röhrl. This was combined with the positive side effect that there was no embarrassing booming outside the cabin. After all, the Morgan itself causes enough of a stir.
As far as the perceived bass was concerned, there was even more than enough. It was actually too much for me in terms of a back and buttocks massage. Now comes the big but: unfortunately, I could only hear the Morgan when it was stationary. However, anyone who knows what a spectacle such prehistoric car creations put on while driving can appreciate that the desired, well-dosed sound effect is likely to be achieved.
Take your Seats, please
But let’s move on to the Seats, sorry, Cupras, as the very stylish products of the Spanish Volkswagen subsidiary are now known beyond rally sport. Apart from the creative and individual solution for the Morgan, their hi-fi sound systems are quite conventional with their mid-range speakers in the doors and dome tweeters in the A-pillars. However, Sennheiser was allowed to let off steam here on the software side with the large central displays from Cupry Leon, Fermentor and Tavascan. The look and feel are impressive. For example, you can intuitively adjust the degree of immersion and also influence the sound focus according to the seat occupancy.
The sound tuning follows the sleek, fresh lines of the Cupras and is particularly suitable for pop and hip-hop, but also works well with rock music. Bass is plentiful, in keeping with the young target group, as is the all-round enveloping surround effect. As far as the powerful bass is concerned, which is particularly lush in the Tavascan, the same applies as for the Morgan: when stationary, i.e. without rolling, wind and drive noises, the final sound impression can only be estimated. Experience has shown that the bass suffers particularly from low-frequency masking effects caused by the aforementioned background noise while driving.
Speaking of background noise: There was also a Volvo-based test vehicle in which simulated driving noises were used to demonstrate the effectiveness of a microphone-based communication technology with which Sennheiser intends to improve conversations between the vehicle crew in the first and second rows of seats in the future.
Cupra-aural sound
A particular highlight, however, was definitely the electric Cupra Tavascan with a very futuristic cockpit design that envelops the front occupants. On the 15-inch central screen, the Sennheiser user interface offers comprehensive sound customization with equalizer and finely adjustable immersive effect to immerse the crew in surround sound, which is generated from normal 2-channel recordings using the AMBEO Concerto software and distributed to a total of 12 loudspeakers. The rich bass is sure to appeal to the younger generation.
Even if it is still far too early to make concrete sound judgments after this short preview in the booth, this much can be said: Sennheiser is a new player to be taken seriously in the market for factory-fitted car hi-fi systems, which is dominated by Harman and Bose with the exception of Burmester (Mercedes, Porsche) and Canton (Skoda).
