The story behind the Bowers & Wilkins audio system in the Jaguar C-X75 concept car
The C-X75 concept is both a celebration of 75 years of iconic Jaguar design and a look into the future of automotive technology. Designed as a range-extended electric two-seater supercar, it explores the outer limits of both performance and sustainability. With plug-in capability the car can achieve a zero tailpipe emissions range of 110km (68 miles) – when running under battery power alone, plus a potential top speed of 330km/h (205mph) and blistering acceleration.
The car demonstrates that it is possible to retain Jaguar’s core values of performance, design and luxury using technology that will make environmentally responsible performance and electric vehicles a practical proposition.
For the audio system of the future, Jaguar came to the experts, Bowers & Wilkins. Following our latest collaboration with Jaguar in the ground-breaking new XJ, our engineers couldn’t wait to take up the challenge of imaging the limits of the ultimate in-car audio system.
The future is built on experience
Imagining a technological world long into the future is in some ways less of a challenge than it might seem when, like Bowers & Wilkins and Jaguar, there’s an impeccable technological heritage on which to build. Knowledge of the road travelled always provides clues as to the road ahead. We can’t claim as long a heritage as Jaguar, but for at least the last 30 years many of the world’s most significant audiophile loudspeaker technologies have had their genesis at our research labs in Steyning near the south coast of England.
These technologies include: Matrix cabinet structures that minimise panel resonance; aluminium driver domes produced a step change in high frequency performance; Kevlar was pressed into service in loudspeaker cones to overcome many of the deficiencies of the paper or thermo-plastic used previously, and extravagantly curved cabinet structures that freed hi-fi speaker design from limitations of flat panels. Just a few examples in the technological heritage that puts Bowers & Wilkins in a better position than any other to imagine audio in the Jaguar of the future.
Moving right up to the present day, Bowers & Wilkins’ recent development, the diamond dome driver, is one technology that would probably still find a place in a Jaguar C-X75 audio system.
Assuming that the direct injection of sound into human consciousness is significantly further into the future than we are considering here, an audio system is always going to demand acoustic power generated from a moving diaphragm.
Polycrystalline diamond displays not far short of the ideal diaphragm characteristics – it is feather-light yet immensely rigid.In the unlikely event that future materials technologists find a way to re-write the periodic table of elements, the diamond dome might be surpassed, but that would be to enter the realms of science fiction.
Digital Signal Processing and Driver Arrays
So for the Jaguar of the future we envisage an audio system comprising a number of arrays of multiple small drivers – 455 in total – each one comprising a diamond diaphragm driven by an integrated, high efficiency digital amplifier chip and miniature moving coil drive element. It is likely that manufacture of the entire diaphragm and drive module would be achieved through a combined vapour deposition and 3D printing technique.
Using arrays of multiple small diaphragms, rather than the relatively large individual drivers we are used to, would bring startling benefits to the Jaguar C-X75 audio system. Assuming Moore’s law, as it applies to processing power, continues on its upward curve, the power needed to apply full bandwidth, real-time digital signal processing (DSP) to each driver in an array will surely be available. Individual DSP would enable the acoustic output of a multiple driver array to be ‘steerable’, so audio within the cabin could be individually optimised for each passenger. Different programme material simultaneously for each passenger would also be feasible, as would the generation of ‘holographic’ audio sources that appear to be located inside, or outside, the car – potentially both entertaining, and of use for active road safety as the audio could be linked with technologies that identify external hazards. Active noise cancellation, if necessary, would also of course be no problem.
Engineering The Interior
Thanks to their ’3D printed’ manufacturing technique, the driver arrays of the Jaguar C-X75 need not be flat but could follow the curved contours of the interior surfaces of the car. The usual requirement for speaker drivers to work in large sealed enclosures would be rendered unnecessary by a combination of digital signal processing and the application of an existing Bowers & Wilkins patented ‘negative spring’ technology. So the driver arrays can be both curved, and require little physical depth. Their energy conversion efficiency would also be inherently high, so despite its remarkable capabilities, the audio system would make only modest energy demands on the car’s electrical systems.
Another existing Bowers & Wilkins technology, Micromesh, is used in the Jaguar C-X75 to create apparently solid yet acoustically transparent surfaces over the driver arrays. Micromesh is a technique that employs ‘chemical drilling’ to create an extremely fine mesh in sheet materials. Once the mesh is created, the material still feels solid and, unless it is back-lit, appears solid too. So Micromesh, and the ability to create curved, slim driver arrays allows the interior and acoustic designers of the Jaguar C-X75 almost complete freedom to place the driver arrays anywhere in the cabin yet keep them completely hidden.
The Future Audio Experience
Human beings have been listening to music for 25,000 years or more, so in looking forward, one thing we can be sure of is that music will play as big a role in peoples lives as it does now. They will probably still be listening to Bach and The Beatles. So audio in the Jaguar C-X75 will be as important for its drivers and passengers as it is now in the XJ, XK and XF. The technology and capabilities of the future audio system will provide an extraordinary in-car experience. It’s such a shame that we won’t be around to hear it.