Synthetic diamond tweeter dome case study
Bowers & Wilkins – the British loudspeaker manufacturer.
To develop a tweeter dome, combining lightness and stiffness to overcome sound quality degradation and distortion which can occur when more typical tweeter dome materials, such as aluminium, are used.
The problem statement was to develop a CVD (chemical vapour deposition) technology that enabled the growth of synthetic diamond in a 3D tweeter dome form at a very high quality. This had to be done in a manner compatible with high volume manufacturing to very tight tolerances.
Synthetic diamond was identified as the material that could address this challenge, due to its extreme stiffness (it has the highest Young’s modulus of any material) in combination with being of relatively low density.
Element Six developed the bespoke synthesis technology, and Bowers & Wilkins and Element Six jointly developed a design of dome which was compatible with the application.
The product was enabled by the development of a unique chemical vapour deposition (CVD) process for polycrystalline diamond, which provided conformal high quality growth of synthetic diamond on a 3-D carrier. The synthetic diamond could subsequently be recovered as free-standing domes, free of cracks, and with high yields.
Element Six overcame a number of engineering challenges in the production of the domes, not least because they are extremely fragile and have a thickness of only a few tens of microns, about half the thickness of a human hair.
More than just a customer, Bowers & Wilkins has been a long-term technical partner of Element Six, who, through pushing the frontiers of innovation in acoustics, enabled the genesis of a pioneering British product via a seamless collaboration.
The result: a synthetic diamond tweeter dome of an exact dimension and thickness which extends the high frequency response (treble) to an extremely high break-up frequency, considerably beyond the range of human hearing, resulting in improved musical detail and clarity. Both the CVD diamond tweeter, and the Bowers & Wilkins Diamond 800 Series range of speakers into which they go, are unique products and provide a level of sound reproduction which is unparalleled.
For Element Six’s immediate customer, Bowers & Wilkins, whose business is based on technical innovation providing extreme performance in sound reproduction, the domes provide a unique selling feature based on a real performance advantage. For the end consumer, the domes provide a quality of listening experience which is unsurpassed.
Very soon after the launch of the Bowers & Wilkins 800 Diamond Series range of speakers, they became the systems stipulated for use in places such as Abbey Road Studios, where the quality of sound reproduction is of paramount importance.
In parallel, Bowers & Wilkins has also sold the Bowers & Wilkins 800 Diamond Series range of speakers at substantial volumes into the more general high-end global consumer audio market.
In April 2012, Element Six and Bowers & Wilkins were jointly awarded the Queen's Award for Enterprise in Innovation for the development of the synthetic diamond tweeter dome.