Bowers & Wilkins Introduces Upgraded 800-Series Diamond Line

Venerable British loudspeaker company Bowers & Wilkins has spent the past six years researching and developing technologies to improve the performance of its already outstanding 800-Series speakers. The result is the new Diamond D4 line, which consists of five stereo models, ranging from the two-way stand-mount 805 D4 at $8000 to the flagship 801 D4 at $35,000 (all prices per pair). The company has reintroduced the iconic 801 moniker for the top model, replacing the 800 D3. Two center-channel speakers are also included in the new series, for a total of seven new products.

The line has been substantially reengineered, starting with a new cabinet design that is reportedly stiffer and quieter than those in the previous generation. Controlling enclosure resonances has always been an important design goal in the 800 Series—B&W’s Matrix internal-bracing structure (see photo) has been in continuous use for more than 30 years, for example. The top panel is now made from cast aluminum, rather than wood, for greater rigidity. The “reverse wrap” cabinet structure, previously reserved for the three top models in the line, is now employed on every model, including the stand-mount 805 D4 (the 805 D3 was built as a conventional box, albeit with curved side panels). I visited the Bowers & Wilkins factory in 2019 and watched how cabinets are made using the “reverse wrap” technique. The cabinet starts as thin layers of wood stacked with an alternating grain pattern and an industrial adhesive between each layer. The assembly is put in a press that bends the wood into the rounded cabinet shape and held in that position until the adhesive cures. An aluminum “spine” is mounted in the opening at the back of the cabinet, adding rigidity. This construction method also results in a smaller and rounded front baffle, reducing diffraction. For the new D4 series, each model’s baffle is reinforced by an aluminum plate, which is also braced to reduce resonances. The classic Matrix bracing structure is now made from thicker panels of plywood rather than MDF, with strategically placed aluminum supporting braces, again to stiffen the cabinet. The midrange drivers are mechanically decoupled from the cabinet, and are fitted with Tuned Mass Dampers (TMD) to further reduce unwanted resonances. Finally, the top 801 D4 features a solid-steel bottom plate around the downward-firing port.

The 804 D4 (the lowest-priced floorstander) is now mounted on a plinth made from steel sheets in a constrained-layer damping structure (the 804 D3 lacked the plinth and downward-firing port of the 803 D3 and 800 D3). The 804 D4 also features much larger spikes.

The new cabinets also benefit from cosmetic upgrades. The aluminum top plate is clad in black or light grey leather, and a fourth cabinet finish has been added, with satin walnut joining gloss black, white, and satin rosenut.

Bowers & Wilkins made big strides when it replaced the Kevlar cones with its Continuum Cone combined with its Fixed Suspension Transducer (FST) technology, the latter a novel surround that reduces the surround’s effect on the sound. In researching sources of driver colorations, Bowers & Wilkins discovered, surprisingly, that the fabric spider behind every cone introduces distortion simply by its own movement. In essence, the spider acts like a second diaphragm, producing unwanted sound. The spider is a doughnut-shaped ring that attaches to the speaker basket at the spider’s outside diameter, and around the voice coil at its inner diameter. The spider’s job is to prevent the cone from moving in any direction other than back and forth. Bowers & Wilkins has reimagined the spider as a minimalist open structure made from a stiff composite material that keeps the voice coil and cone in proper alignment, yet doesn’t generate any sound of its own. The company claims that this development, called Biometric Suspension, dramatically increases midrange transparency and realism. The new suspension is used on the midrange drivers throughout the 800 D4 Series.

The bass drivers have also been redesigned, with revised motor systems along with the Aerofoil Cone, a diaphragm made from carbon-fiber skins around a light foam core. The core thickness varies to deliver maximum stiffness where it’s needed, while keeping mass low.

Given the performance and value of the previous generation 800 Series, we’re eager to put this new line through its paces. Watch for our reviews of the 805 D4 and the flagship 801 D4 in upcoming issues.

801 D4: $35,000. Three-way, four-driver floorstander

802 D4: $26,000. Three-way, four driver floorstander

803 D4: $20,000. Three-way, four-driver floorstander

804 D4: $12,500. Three-way, four driver floorstander

805 D4: $8000. Two-way, two-driver stand-mount

HTM81 D4. $7500. Center-channel speaker

HTM82 D4. $5500. Center-channel speaker