Bowers & Wilkins 804 D4
Stereophile|January 2022
The boxes sit there in our storage units, opposite the 20 banker’s boxes that hold 33 years’ worth of product-measurement workbooks. The two large boxes are for the Bowers & Wilkins Matrix 801s my wife owned when we got married in 1987.1 The four smaller boxes are for the B&W John Bowers Silver Signatures and their stands, which I purchased after reviewing them in June 1994.2 Both pairs of speakers gave superb sound quality back in the day, but now they sit there in the storage unit, their boxes giving me recriminatory looks when I visit.
JOHN ATKINSON

LOUDSPEAKER

Stereophile has reviewed many Bowers & Wilkins speakers since the first, the “pregnant kangaroo” DM6, in December 1977.3 The most recent was the 705 Signature stand mount, which I wrote about in December 2020.4 I concluded my review of the 705 Signature, which costs $4000/ pair, by writing that “this elegant loudspeaker stepped out of the way of the music in a very satisfying manner.” So, last summer, after I watched a video presentation of Bowers & Wilkins’s new 800 D4 series loudspeakers, I asked for review samples of the 804 D4 floor stander, which costs $12,500/pair.

The 804 D4

The D4 800-series loudspeakers are mostly similar to the D3 models,5 but they incorporate a few revised and upgraded design features. The 804 D4 differs most from its predecessor in that it features what the manufacturer calls the “reversewrap cabinet” that had been used for the larger floorstanding 800 series models. The elliptical-plan enclosure has a flat back faced with a vertically ribbed aluminum panel, while the front baffle is gently curved to optimize dispersion. The midrange unit and twin woofers are housed in circular aluminum pods mounted to the baffle. The enclosure has a cast aluminum top panel, covered with a padded material, and the internal Matrix bracing now uses panels made from solid plywood rather than the previous MDF, these reinforced with aluminum bracing.

SPECIFICATIONS

Description

Three-way, reflex-loaded, floor standing loudspeaker. Drive units: 1 (25.4mm), diamond-dome tweeter; 5 (130mm) Continuum-cone, FST midrange unit; two 6.5 (165mm) Aerofoilcone woofers. Crossover frequencies: not specified. Frequency response: 24Hz– 28kHz ±3dB. Frequency range: 20Hz–35kHz. Nominal impedance: 8 ohms. Minimum impedance: 3 ohms. Sensitivity: 89dB/2.83V/m. Recommended amplifier power: 50–200W into 8 ohms, unclipped program. Supplied accessories: jumper cables, rubber-tipped feet, and spikes, with a spanner and rod to fit the latter.

Dimensions 42.17 (1071mm) H × 12.05 (306mm) W × 15.4 (391mm) D. Weight: 81.1lb (36.85kg) each.

Finish Gloss Black, Gloss White, Satin Rosenut, Satin Walnut.

Serial numbers of units reviewed 2122 0000811 & 0000812. “Made in England.”

Price $12,500/pair. Approximate number of North American dealers: 300. Warranty: 5 years.

Manufacturer B&W Group Ltd., Dale Rd., Worthing, West Sussex BN11 2BH, United Kingdom. US distributor: Bowers & Wilkins, 5541 Fermi Ct. N, Carlsbad, CA 92008. Tel: (800) 370-3740. Web: bowerswilkins.com.

The 1 tweeter, which uses a vapor-deposited diamond diaphragm, is mounted at the front of a 12-long tapered tube machined from a solid aluminum billet. This sits on the top of the enclosure with two compliant mounts. The tweeter’s motor has a vented pole-piece so that the back wave can be absorbed within the tube. (I couldn’t detect any output from the end of the tube.) B&W says that “the tweeter’s motor assembly has been re-engineered to allow the drive unit to ‘breathe’ more effectively with no loss of performance. The result is a notable reduction in the resonant frequency behind the tweeter dome.”

The 5 midrange unit uses a cone formed from Bowers & Wilkins’s now-familiar silver-colored, woven Continuum material. This material is said to be very light and stiff, with very high self-damping. As with earlier generations of this driver, it dispenses with a conventional surround in favor of what B&W calls its Fixed Suspension Transducer (FST) technology. Instead of the conventional fabric “spider” that keeps the voice-coil centered within the motor, the D4 series’ midrange driver features a “composite Biomimetic Suspension” system that presents lower air resistance to the rear of the drive unit’s diaphragm. The result, according to B&W, is “unprecedented midrange transparency and realism.”

The two 6.5 woofers use the manufacturer’s Aerofoil cones, which have a low-mass “syntactic foam” core, with a carbon-fiber skin that varies in thickness from a minimum around the central voice-coil, increasing as the radius increases then thinning again as it approaches the surround. This topology is said to maximize stiffness without adding mass. The D4 speakers add a new foam Anti-Resonance Plug, which B&W claims “gently braces the voice coil and lowers distortion as the cone moves through its operating range, ensuring even cleaner bass.”

The woofers are reflex-loaded with a flared “Flowport,” which has small dimples in its surface to reduce turbulent air noise. While the 804 D3’s port was on the front baffle, the D4’s port fires downward into the 1-high airspace between the enclosure and the cast aluminum base; the enclosure is supported on four short legs. On the base, a constrained-layer steel damping sheet is said to control resonances. The speakers arrive with rubber-tipped feet, which can be replaced with heavy-duty carpet-piercing spikes that are included in the accessories box.

Crossover details are not available. Electrical connection is via two pairs of high-quality binding posts at the bottom of the rear plate. Supplied jumper cables allow for single-wiring.

MEASUREMENTS

I used DRA Labs’ MLSSA system, a calibrated DPA 4006 microphone, and an Earthworks microphone preamplifier to measure the Bowers & Wilkins 804 D4’s frequency response in the farfield. My primary axis for the measurements was level with the tweeter, but I also performed a series of tests on an axis level with the midrange unit, which is 36 from the floor, the height of my ears in my listening chair. I used an Earthworks QTC-40 mike for the nearfield and in-room responses.

Fig.1 Bowers & Wilkins 804 D4, electrical impedance (solid) and phase (dashed) (2 ohms/vertical div.).

Fig.2 Bowers & Wilkins 804 D4, cumulative spectral decay plot calculated from output of accelerometer fastened to center of side panel midway between the woofers (MLS driving voltage to speaker, 7.55V; measurement bandwidth, 2kHz).

Fig.3 Bowers & Wilkins 804 D4, acoustic crossover on tweeter axis at 50”, corrected for microphone response, with the nearfield response of the midrange unit (green), the summed nearfield responses of the woofers (blue), and the port (red), respectively plotted below 600Hz, 1.8kHz, and 900Hz.

Continue reading your story on the app

Continue reading your story in the magazine

MORE STORIES FROM STEREOPHILEView All

Revinylization

Round Trip: Ornette Coleman’s Blue Note sides

4 mins read
Stereophile
March 2022

CH Precision D1.5 SACD/CD/MQA-CD Player/Transport

There’s a school of thought that maintains that among all hi-fi components, the D/A converter is easiest to perfect or come close to perfecting. Just make sure that every sample is converted accurately, that there’s little rolloff in the audioband, that aliased images are suppressed almost completely, and that background noise is extremely low, and you have a top-quality D/A processor. Use of a high-quality DAC chip is assumed.

10+ mins read
Stereophile
March 2022

Analog Corner

Paradox’s remarkable Phono 70 Signature MC phono preamplifier

10+ mins read
Stereophile
March 2022

GRAMOPHONE DREAMS

Stax, EAR, and Bob’s Devices

10+ mins read
Stereophile
March 2022

SINGING TO THE SOUL

THE MAGIC OF ART SONG ON RECORD

10+ mins read
Stereophile
March 2022

MayFly Audio Systems MF-201A LOUDSPEAKER

If you’ve ever read Homer’s Iliad, you probably remember the Cata-log of Ships at the beginning. It’s an exhaustive record of the contingents the Achean army deployed against Troy, naming the commanders, their hometowns, the number of ships in each contingent, and more. Not to put too fine a point on it, it’s a snoozefest. It makes you dread what’s next. But of course, if you come to this point only to abandon the Iliad in frustration, you’ll miss the fabulous war epic that follows, chockablock with action, drama, and romance.

10+ mins read
Stereophile
March 2022

Gold Note PH-1000 PHONO PREAMPLIFIER

Gold Note’s $11,999 PH-1000 is by a con-siderable margin the most sophisticated, most configurable phono preamplifier that any audio manufacturer has ever produced, at least that I know of. Remarkably, considering all that flexibility and sophistication, using and adjusting the PH-1000 is straightforward.

10+ mins read
Stereophile
March 2022

“Music Was Mine to Experience.”

For all its ghastliness and heartbreak, the COVID-19 pandemic has been good to Keb’ Mo’. When the virus hit the US, it forced the cancelation of a string of his concerts. “I was getting a little burned out on touring,” he confesses.

10+ mins read
Stereophile
February 2022

Book Review

The Secret History of Washington, DC, R&B

4 mins read
Stereophile
January 2022

Forget about the sound of the recording.

MY BACK PAGES

5 mins read
Stereophile
February 2022