Bowers & Wilkins 804 D4

The 804 D4 is the most compact floorstanding loudspeaker in the 800 Series Diamond range — and it makes a compelling case that a smaller cabinet need not mean a diminished ambition. Every significant technology from the flagship 801 D4 is present and correct: the diamond dome tweeter, the Continuum FST midrange driver, the Aerofoil bass cone. What the 804 D4 offers that its larger siblings cannot is a footprint and a scale that suits a genuinely wide range of domestic rooms — rooms where the 803 D4 would dominate, the 804 D4 integrates naturally, yet without asking for any meaningful concession in performance. Martins Hi-Fi is the second oldest Bowers & Wilkins dealer in the world, and we consider the 804 D4 one of the most musically satisfying loudspeakers in the entire 800 Series Diamond range.

Diamond Tweeter and Tweeter-on-Top

The 804 D4 uses the same solid diamond dome tweeter as every loudspeaker in the 800 Series Diamond range above it — housed in a Solid Body aluminium enclosure and mounted in the Tweeter-on-Top configuration above the main cabinet. The separation this arrangement creates between the tweeter and the rest of the enclosure is not cosmetic — it provides complete mechanical and acoustic isolation, allowing the diamond dome to operate in an environment entirely free from the vibrations generated by the bass and midrange drivers below. High frequencies are resolved with the extraordinary precision and purity that only a solid diamond diaphragm can deliver, with no harshness and no compression at any listening level.

Continuum FST Midrange Driver

The midrange driver uses Bowers & Wilkins' Continuum cone — the woven composite material developed to replace Kevlar in the 800 Series — in a Fixed Suspension Transducer mounting that eliminates the conventional foam surround and the resonance it introduces. In the 804 D4, the midrange driver is mounted directly in the upper section of the main cabinet rather than in a separate Turbine Head enclosure — a packaging solution that reflects the 804 D4's smaller overall scale, but one that retains the Continuum cone and FST mounting that make the midrange performance of the 800 Series so distinctive. Biomimetic Suspension refines the driver's behaviour at low signal levels, recovering micro-dynamic detail that conventional suspension systems leave behind.

Aerofoil Bass Driver

A single Aerofoil profile bass driver handles the 804 D4's low-frequency reproduction — the same variable-thickness composite cone technology used across the 800 Series Diamond range, derived from aerospace engineering principles to achieve the stiffness of a heavy cone without the mass penalty. The bass driver is mounted in a dedicated aluminium pod at the base of the cabinet, clamped to an internal aluminium plate at the stiffest point of the enclosure — providing the mechanically stable, low-resonance foundation that allows the 804 D4's bass output to be as composed and articulate as its midrange and treble. An Anti-Resonance Plug within the bass enclosure damps the cabinet's primary internal resonance, keeping the bass clean and defined at all levels.

Matrix Cabinet Construction

The 804 D4's cabinet employs the Matrix internal bracing system — the lattice of interlocking panels bonded throughout the enclosure that distributes vibrational energy across the entire structure, suppressing the panel resonances that colour the sound of conventional box loudspeakers. The D4 generation brings an updated Matrix design with a new aluminium top plate, stiffening the upper section of the cabinet and improving the mechanical interface between the enclosure and the tweeter body above. The result is an enclosure of exceptional rigidity that contributes nothing of its own to the sound of the 804 D4.

Technical Specifications

Who Is It For?

The 804 D4 is for those who want full 800 Series Diamond technology in a room that suits a compact floorstander. It is a genuinely full-range performer — not a stand-mount with a bass cabinet bolted beneath it — and it rewards quality amplification and careful placement with a performance that regularly surprises those hearing it for the first time. Those considering the 804 D4 alongside the stand-mount 805 D4 will find the extra bass extension of the floorstanding design tells clearly in a room of any meaningful size. For those wishing to extend the low-frequency performance further still, the Bowers & Wilkins DB2D subwoofer pairs naturally with the 804 D4, and the DB1D offers a more compact alternative.

Buying from Martins Hi-Fi

Martins Hi-Fi has been in Norwich since 1968. Elizabeth Gould runs the business today, and we stock only brands we have heard properly and stand behind. As the second oldest Bowers & Wilkins dealer in the world, we have a depth of experience with the 800 Series Diamond range that very few retailers can match. The 804 D4 is available to hear in our Norwich showroom, and Dave and Chris can demonstrate it alongside the 803 D4 and 805 D4 to help you establish exactly where in the range your system and room are best served.

Contact us at [email protected], call 01603 627010, or WhatsApp on 07554 687137. You can read more about how we work on our Why Martins Hi-Fi page. We are at 85–91 Ber Street, Norwich, NR1 3EY.