B l o g

The New 800 Series from Bowers & Wilkins

It’s easy to upgrade an existing speaker range – unless, of course, you decide to go back to basics and do it the hard way

When most loudspeaker manufacturers ‘upgrade’ a range, that’s just what they do: maybe a different drive-unit here or there, some re-tuning to spruce up the sound, and perhaps a new finish. However, that’s not the way Bowers & Wilkins thought when re-inventing its famous 800 Series, with the result that you can count the number of components carried over from old to new on your fingers – and in fact on one hand if you don’t count each terminal individually! This isn’t a minor revamp, but a complete redevelopment of a celebrated range, with little more than the Diamond Dome of the tweeter retained: and even then only the dome itself has been kept, with everything behind it, from the suspension to the tube housing, re-invented. No stone unturned In all, almost 870 of the components used in the 802 D3 speaker are brand new, leaving only that dome, the terminals and a few other minor components to be carried over. It’s the result of seven years of analysis, development and ‘what ifs’ at the company’s research centre in Steyning, just a few miles from the factory in Worthing where all the new 800 Series Diamond speakers are made. To develop the new range, the Bowers & Wilkins R&D team went back to basics, examining every component of the old models with state of the art tools and development resources: and in almost every case, room for improvement was found by changing the way even the most basic components were designed and made. From the cabinets to the internal Matrix structure, and from the fundamental design to the materials chosen, Bowers & Wilkins’ engineers found that just about everything could be better – and in the new 800 Series Diamond, it is.



Continuum cone One of the most obvious changes – apart from the new look of the speakers – has been the replacement of the Kevlar midrange driver, for 40 years a Bowers & Wilkins "signature". Good though the ultra-stiff cone was, and extensively though it has been developed since it was first considered in 1974, the engineers just kept on looking into alternatives, and eight years ago the basics of the new Continuum cone were established. Over the intervening years, the design, using a coated woven material with a metallised coating, continued to be developed, with over 70 versions of Continuum being tried, tested, measured and listened to. After all, replacing that famous Kevlar cone was always going to be a big deal! And though the cones do seem very different when you handle them, the Continuum design being highly flexible when not mounted in its chassis, the principle is the same as the Kevlar driver: it’s all about controlling the ‘break up’ of the cone when signal is applied, in an attempt to get the most accurate pistonic motion. In other words, the cone as a whole moving back and forth in response to the electrical signals, rather than introducing any colorations of its own. The exact details of the cone, its materials and its construction, are still under wraps – Bowers & Wilkins has applied for patent protection for the design, and has no intention of sharing it with other manufacturers, so central a part of the 800 Series Diamond is Continuum – but Head of Research Martial Rousseau describes the breakthrough as like doing to the midrange cone what the company did with the tweeter dome when it moved from aluminium to its Diamond Dome technology.



Turbine head What’s more, in the holistic re-consideration of the design of the speaker, the chassis was redesigned to become more acoustically ‘dead’, so it didn’t add coloration by ‘ringing’, and the housing for the Continuum driver was also completely rethought. For years, the 800 Series speakers have used a spherical housing tapering off to a version of the Nautilus tube, made from Marlan, a combination of mineral filler and resin used in a number of high-tech applications. However, the analysis of the Marlan head under the stresses of playing music, revealed by the measurement and computer modelling available to the Steyning engineers, revealed there was significant room for improvement, leading to the development of the new Turbine head, featured in the 802 D3, the forthcoming 800 D3 and, for the first time, the 803 D3, which now has a completely new ‘headed’ design. Having established the superiority of the physical design of Turbine over the old head, using prototypes made of the same materials (and at one stage mounted on an 802 Diamond to which a chainsaw was taken to enable the test designs to be mounted), it remained to choose a material for the head. Aluminium provided the answer, with a one-piece casting delivering the required shape and stiffness before being tested with various versions of an internal bracing strategy, and tuned mass damping to deal with any remaining resonances. The result is a very rigid, very inert (and very heavy) component, made in one piece complete with the finalised bracing and damping, and in two sizes: one, weighing around 11kg, for the 803 D3, and an even larger (and heavier!) version for the 802 D3 – and the 800 D3 to be launched in Spring 2016. It’s mounted differently, too: atop the main cabinet rather than in the sloping shoulders of the old model, which is why that chainsaw was needed to test prototypes in situ!



Solid body tweeter Atop the Turbine housing sits the new Solid Body Tweeter housing, and as already mentioned even this is all-new: it’s now manufactured from a single piece of aluminium, for greater rigidity and damping. Strike the old tube and you get a noticeable "ting" sound; do the same with the new one and there just a dull initial impact noise, with no ringing. To protect the ultra-light Diamond Dome, an integral mesh is fitted over the front of the tube: this is fixed in place, and of course optimised for its effect on the sound of the famous drive unit from which the speakers take their suffix. Only if servicing is required can it be removed using dedicated tools. An interesting side-effect of the new tube design addresses one aspect of loudspeakers few users ever consider – heat. As well as producing motion of their diaphragms, drive units also generate thermal energy, and part of the skill of the speaker engineer is managing and dissipating this heat, which can affect the operation of the driver. The new Solid Body tweeter tube loses heat so efficiently that the tweeter runs some 30C cooler when working hard – a not insignificant advantage. The same thinking informs the metal ‘spine’ running down the rear of the headed 800 Series Diamond speakers: another major source of heat in loudspeakers is the crossover network, used to split the incoming signal between the drive units so each can work optimally, and the headed models in the range mount the crossover components on this "spine", which is finned to the outside to act as a heatsink. It’s all about ensuring the effortless power-handling and control of the new speakers, as when you drive any speakers hard, both drivers and crossovers can generate significant heat.



Aerofoil cones At first glance, all the action in the lower parts of the speaker seems to be in the cabinets, with their new ‘reverse wrap’ design in which the front baffle and side panels are formed in a single structure: after all, the bass units look just like the familiar Rohacell carbon fibre and foam sandwich designs used in the previous 800 Series Diamond speakers. Not so: in fact the bass drivers, though still a sandwich, are of a new Aerofoil construction, with the cone having a variable thickness across its radius. It’s thin at the centre of the cone, thickens up as you go across the profile, and then tapers down again where it meets the surround. Developed using a combination of materials science, analysis and computer-modelling, this produces a driver of even greater rigidity than the old Rohacell design without adding mass, and contributes to a more accurate pistonic motion for powerful, deeper and yet more tightly-controlled bass.



Cabinet construction The bass drivers in the new 800 Series Diamond speakers are mounted in aluminium ‘pods’, sitting proud of the main baffle: this is an intrinsic part of the design, and aimed at allowing that curved front panel for improved dispersion characteristics and minimal interference, while allowing a solid mounting of those substantial drivers, with their high-power neodymium magnets. All the new headed speakers use the same ‘reverse wrap’ construction: that single piece front-and-sides, formed in giant presses from hand-selected ‘leaves’ of solid wood for optimal strength and rigidity. It’s all part of the complete reconfiguration of the Worthing plant for the construction of the speakers – and it is about construction, not assembly, as with the exception of a few components from outside suppliers, just about everything in the 800 Series Diamond is made in-house. Get the engineers to show you the computer modelling of the way old and new cabinets react to the load placed on them when those powerful drive-units are in action and yes, the amplitudes of the movement are enhanced to show you what’s happening – well, either that or they modelled the designs in blancmange! – but you can see how much more rigid is the new design. And that’s just the start…



Matrix For many years – in fact, ever since the Matrix 801 speaker – Bowers & Wilkins has used Matrix internal bracing. This isn’t just reinforcement at key points of the cabinet, as you’ll find in just about any speaker, but a complete rigid latticework structure within the enclosure, all designed to make the assembly as stable, as "dead", as possible. In the new 800 Series Diamond we have the Matrix reloaded, with new materials and new construction methods, designed to make the whole thing even more inert. In the place of the old MDF is stronger, more rigid plywood, with fewer cut-outs allowing more wood for even more solidity, and aluminium fittings used to reinforce the joints of the Matrix structure, and the interface between the internal ‘frame’ and the main cabinet shell. It all adds up to an assembly designed to get ever closer to the speaker ideal: the ability to hear only what the drive units are doing, rather than experiencing the music through colorations introduced by the need for an enclosure. That’s what brings the 800 Series Diamond nearer to the desire of company founder John Bowers to develop speakers delivering what he described as "True sound". The best speaker, he said, "isn’t the one that gives the most, it’s the one that loses the least"



The little details That’s the thinking behind the entire technology of the new 800 Series Diamond range, from the infinitesimally small movements only visible when you subject drive units to techniques such as laser interferometry, pioneered by Bowers & Wilkins in the field of speaker development, right through to the heavy engineering of making ultra-strong, ultra rigid cabinets for those drivers to work in. You can see and feel the solidity of the new 800 Series Diamond if you try to pick up one of the new speakers – or rather don’t, as you may well injure yourself. The last 802 Diamond speaker weighed a not-insubstantial 72kg per speaker; the 802 D3, thanks to those 868 changes, is 94.5kg. And simply dealing with that greater mass required its own engineering solutions. The larger 800 Series Diamond speakers come with heavy integrated metal plinths, which are fitted with silent-running sealed-bearing castors to make it easy to move them around without any danger of the undercarriage rattling along with the music. Also fitted are novel spikes: retracted when the speakers are delivered, they are easily deployed using large ‘wing nuts’, lifting the speakers off the castors, then tightened in position using a small "tommy bar" supplied with the speakers – and all without the need to put the speaker on its side and then lift it into position again. At almost 95kg, you really don’t want to be doing that kind of heavy lifting! And it’s when you see how the speakers arrive that you realise that not a single detail, however small, has been missed in the development of the 800 Series Diamond: the packaging is designed to unwrap from around its contents, leaving the speaker standing on a lower platform. Pull out a piece from the side of that platform and slot it back into a cut-out provided to one side, and you have a ready-made ramp down which you can roll the speaker on its castors into your desired position. It’s a simple – and extremely elegant – solution. And that shows the detailed thinking of the Bowers & Wilkins engineers: from the smallest component to the handling of the complete speaker, nothing has been taken for granted in the design and construction of the 800 Series Diamond. It’s that now-famous idea of things improving not by chance, but by change, and informs the company’s belief that research and development – whether into components, completed products or the way they are made – should never be a one-shot thing, but a continuous process. Or, as Bowers & Wilkins Head of Research Martial Rousseau puts it (with more than a little understatement), As engineers we always try to make things better.

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