Why form follows function at Bowers & Wilkins

Bowers & Wilkins has long been an advocate of innovative design, and we have a long and very successful working relationship with two renowned British designers in Kenneth Grange and Morten Warren. However, form always has to follow function in great loudspeaker design, and sound acoustic principles lay behind the most iconic designs in Bowers & Wilkins 45 year history.

Form always follows function at Bowers & Wilkins. Our most iconic design signatures – the head unit of an 800 Diamond, the iconic shape of a Zeppelin Air, the curve of a Nautilus cabinet, the yellow Kevlar of our mid-range drive units – are arrived at for solid engineering and acoustic reasons.

And, because the performance of a loudspeaker is directly affected by the geometry of the product and the materials from which it is constructed, this makes it a particularly tough challenge for an industrial designer. They can’t quite fly off into the realms of fantasy as they would with other domestic products.

But Bowers & Wilkins has a long-standing, incredibly fruitful relationship with two outstanding British designers.

Kenneth Grange and Morten Warren have histories with Bowers & Wilkins that stretch back many years – since the early 1970s in the case of Kenneth, and the 1980s with Morten, and we – and our customers – continue to reap the benefits.

Challenging pre-conceptions

The relationship between Bowers & Wilkins and both men is one of trust and common understanding, where both parties feel the ability to challenge the thoughts and preconceptions of the other, and together push the boundaries of design to produce not only some of the best performing and most successful products in the history of hi-fi, but also arguably some of the most beautiful and iconic designs.

You can read a detailed article on Kenneth Grange’s long history with Bowers & Wilkins here, but suffice to say, right from the start Kenneth’s designs for Bowers & Wilkins were based on our pioneering acoustic principles and the research and innovations coming out of our Steyning Research Establishment (often called the University of Sound).

The Bowers & Wilkins DM6, designed by Kenneth Grange For his first Bowers & Wilkins design, Kenneth developed an icon. The DM6. A model that would change the way the company designed loudspeakers forever. However, the distinctive look of the loudspeaker often dubbed the Pregnant Penguin was in a large part down to the fact that the drive units were placed on different planes – a purely technical aspect of the speaker design. But what Kenneth did, as you can see in these drawings, was take that technology, and make it beautiful.


One of the most distinctive visual attributes of Bowers & Wilkins loudspeakers since the 1970s has been the yellow drive units. Whether it’s the mid/bass cones found on bookshelf speakers such as the 805 Diamond, or the FST midrange units found on floorstanding models such as the 804 Diamond and in the head units of the 800 Diamond, more of which later, you’ll find the distinctive yellow cone.

We use Kevlar to produce a semi-flexible cone, which exhibits a peculiar style of break-up behaviour, not found in more conventional materials, that maintains a more constant dispersion pattern at all frequencies in its range and transmits far fewer delayed, time-smearing sounds to the listener. You can read more about the technical reasons why we use Kevlar, and watch a video on the topic here.

But why yellow? Well, the natural colour of Kevlar is canary yellow, which tends to darken to gold with age. It can’t be bleached white, but it can be dyed to some extent, to darker colours, such as the dark blue which we use on Custom products. In the early days the yellow was retained to distinguish us from the rest, but even though others copied the colouring, the colour is still very much associated with Bowers & Wilkins. Plus we get levels of performance from Kevlar that others struggle to achieve. Kevlar FST Midrange Cone


Bowers & Wilkins is also keen that while innovative design usually starts in our high-end flagship ranges, if the technology is sound, and scalable, it will eventually work its way into many of our other products – if not all of them!

Nautilus Tapering Tubes The most obvious example of this comes in the form of Nautilus. What started out as a research project to design a no-holds barred transducer, has resulted in technology that can be found in the shape of the Nautilus tapering tube in everything from our 800 Series Diamond range to the MM-1 computer speakers and automotive in-car audio. 

Nautilus tapering tubes, whether atop the head of an 802 Diamond or expertly crafted inside the compact cabinet of an M-1 monitor offers sound acoustic benefits such as soaking up the wayward sound energy and reducing resonances to an insignificant minimum. You can learn more about Nautilus tapering tubes here, but this technology only really becomes visible when coupled with another… the de-coupled tweeter, or tweeter-on-top.

Tweeter on top

Taking the tweeters outside the box – and decoupling them from the main cabinet – maximises the benefits. As mentioned above, the Tweeter on top is another major design concept, which has both very sound acoustic principles and the potential to look amazing too.

It avoids the situation with normal cabinet construction, where sound waves from the tweeter not only radiate towards the listener but also travel along the baffle surface towards the cabinet edges. It also allows its time-alignment with the midrange driver to be finely adjusted so the two outputs are perfectly in phase through the crossover region. 

For possibly the most distinctive example of these you only need to look at our limited edition Signature Diamond loudspeaker, designed by Kenneth Grange for our 40th anniversary. Here our diamond tweeter is housed about the curved cabinet of the Signature Diamond in an enclosure of pure marble.

Signature Diamond with tweeter on top

Curved cabinets

The cylindrical cabinet of the Signature Diamond is an extreme expression of another Bowers & Wilkins core principle – the benefits of curved enclosures. This has proven advantages to performance, especially in the area of dissipating unwanted resonances within the cabinet.

800 Series curved back cabinet Our 800 Series range has featured curved cabinets for many years, and you can watch a video of how we manufacturer the curved cabinets for the 800 Series Diamond in our Worthing, UK, factory here. But once again, this is form very much following function, and designer Morten Warren transforms a technological principle into premium-quality furniture.

Head units

Another key aspect of the 800 Series Diamond, both aesthetically and technically, are the head units found on the 800 Diamond and 802 Diamond. Crafted from inert Marlan® composite, the internal cavity – a sphere closely coupled to a short tube – absorbs most of the sound from the back of the driver, with the fibre filling mopping up the last vestiges. On the outside, the glossy teardrop shape smoothly disperses the sound around the speaker creating a solid, three-dimensional image. 

Even when the head unit is not possible, because of reasons of scale and economics, the principles remain the same as is evidenced by the new PM1 loudspeaker. You can view a video of the PM1’s industrial designer Morten Warren talking about the shape of the PM1 here.

PM1 Speaker


Another Bowers & Wilkins design classic, both in terms of acoustic principles and aesthetics is the iconic PV1 subwoofer. In nature, the strongest shape is always a sphere, and we take that concept to its logical conclusion in this ground-breaking subwoofer, which even seven years after being launched continues to win plaudits and awards for its performance.


It’s not just our traditional speakers that benefit from this form follows function ethos. Zeppelin Air, and the original, show stopping Zeppelin before it, have an iconic design that makes them stand out from the crowd, but the curved shape, and tapering edges fit comfortably with our core principles that the smaller the drive unit, the smaller the baffle around it should be. Therefore placing the tweeters at the edges of the baffle help it’s open, clear room-filling performance.

Micro Porous Filter

And it’s the same for headphones. The C5 in-ear headphones feature two apparently aesthetic touches, that are actually considered engineering and acoustic principles. The Secure Loop design keeps the earphone comfortably in place, therefore aiding both comfort, and performance. But even more obvious is the Micro Porous Filter, the metallic bubbles on the rear end of the earphone that not only give the C5s their distinctive look, but also contribute to the open and natural performance that reviewers have commented upon.
You can view an interview on the C5 in-ear headphones with Morten Warren here.
C5 Micro Porous Filter

So, while Bowers & Wilkins is justifiably proud of the wide range of products it makes in terms of the look and design, the vast majority of the iconic and – we think – aesthetically pleasing choices made about look, finish, and choice of materials, have their roots firmly in the hard science of acoustics. And that is something we are even prouder about.


  • HP says:

    All makes simple sense! If listening to any unit fails to drive that point already! Have had a Zeppelin for 3 years and got another to provide it total coupled sound , unfortunately a few weeks before the Air came out, but both are hooked through apple airports so I hv almost the same result! Again simple sense , sounds superb! And they look beautiful too! They sit like art in my house!

  • pervertt says:

    Following the theme of this story, why does B&W continue to make speaker cabinets largely out of wood? Wood may be fine for some musical instruments, but in a speaker you would want a material that is acoustically inert. I’m thinking fibrous cement or the like, materials that do not resonate and that can be moulded into different shapes.

  • DigiPete says:

    Digital input active speakers with building DAC and optional DSP/room correction and active or digital X-over with bi/tri-amp would significantly raise quality and value for money. IMO. Looking forward to it!

  • Mr Jorge Andrade says:

    Who knows it is true for a new signature Aniversary Finish .2012.

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