The loudspeaker that sets the standard other high-end designs will be judged by for years to come. Endowed with every new technology the 800 Series Diamond™ has to offer, the reference-quality 801 D4 is an instant icon. The all-aluminium Turbine Head houses our Continuum™ midrange cone in a stiff and critically damped enclosure to eliminate unwanted resonances. At the same time, it’s decoupled from both the bass enclosure and the tweeter body. The result? The most realistic midrange sound yet. Innovation is at the heart of everything B&W does. They question, they examine, they understand and then they evolve. They use computer modelling to explore and reimagine every aspect of loudspeaker design. 801 D4 is the flagship and the most powerful model in the new 800 Series Diamond range. Its no-compromise design includes all our most advanced technologies in their purest, most optimised form alongside crossover components of the highest quality. You want a reference loudspeaker? This is it… Diamond Dome Tweeter: Bowers & Wilkins’ most advanced high-frequency driver delivers unparalleled treble accuracy, air, and spatial realism. Solid Body Tweeter-on-Top: Precision-milled from solid aluminum to minimize resonance and enhance imaging clarity. Continuum™ Cone FST™ Midrange Driver: Offers open, transparent midrange with incredible vocal and instrumental fidelity. Turbine™ Head Enclosure: Acoustically optimized aluminum midrange housing eliminates resonance and coloration, ensuring stunning vocal accuracy and lifelike sound imaging. Matrix™ Bracing System: Advanced internal bracing with metal reinforcements minimizes cabinet vibrations, ensuring tighter bass, lower distortion, and improved clarity across all frequencies. Biomimetic Suspension: Innovative midrange suspension technology replaces traditional fabric spiders to dramatically reduce air pressure and coloration—delivering breathtaking vocal clarity and detail. Anti-Resonance Plug: Integrated into the Aerofoil bass cones to suppress distortion and tighten low-end performance. Aerofoil™ Cone Bass Drivers: Advanced carbon fiber/foam-core drivers provide powerful, articulate bass with minimal breakup. Flowport™ Technology: Dimpled, rear-facing port design ensures smooth airflow and cleaner bass, even at high volumes. Flagship Design & Craftsmanship: The most refined, fully optimized loudspeaker Bowers & Wilkins has ever created, built with premium materials and stunning finishes.