Bowers & Wilkins Diamond Series 804 D4 loudspeaker

The boxes sit there in our storage unit, 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 (footnote 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. 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.

Stereophile has reviewed many Bowers & Wilkins speakers since the first, the "pregnant kangaroo" DM6, in December 1977. The most recent was the 705 Signature standmount, which I wrote about in December 2020. 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 maner." So, last summer, after I watched a video presentation of Bowers & Wilkins's new Diamond Series 800 D4 series loudspeakers, I asked for review samples of the 804 D4 floorstander, which costs $12,500/pair.

The 804 D4
The D4 800-series loudspeakers are mostly similar to the D3 models (footnote 2), 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 "reverse-wrap 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.


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.


Setting up
Optimizing the positions of the 804 D4s proved to be a little more difficult than I was expecting from my experience with the 705 Signatures. With the speakers as close to the wall behind them as I could manage with the short flight of stairs to the vestibule behind the right speaker, this gave the best transition between the lower midrange and upper bass, but the lowest-frequency room mode was excited too much. I moved each speaker forward so that the mode was lower in level, but now the upper bass was too quiet.

I ended up with the 804 D4s close to where the PSB Synchrony T600s that I reviewed in the November 2021 issue worked best: each front baffle 131" from the listening position and 81" from the front wall. The woofers of the left 804 D4 were 36" from the LPs that line the nearest sidewall; the right-hand speaker's woofers were 54" from the sidewall behind the bookshelves that line it. When I sit in my listening chair, my ears are 36" from the floor, level with the 804 D4's midrange unit. The speakers were toed-in to face the listening position. Once I had decided on their final positions, I replaced the rubber-tipped feet with the spikes. I didn't use the magnetically attached grilles.

Footnote 1: You can find my measurements of this pair of Matrix 801s here.

Footnote 2: Kal Rubinson reviewed the D3-series 802 loudspeaker in June 2016.

B&W Group Ltd.
US distributor: Bowers & Wilkins
5541 Fermi Ct.
Carlsbad, CA 92008
(800) 370-3740

brenro's picture

Fussy with positioning. Fussy with system matching. Mediocre measurements. After all that still overly bright and fatiguing. This has been Bowers and Wilkins for a decade or more.

georgehifi's picture

I always study the measurements first before reading any subjective reviews.

Cheers George

John Atkinson's picture
The measurements are posted:

John Atkinson
Technical Editor, Stereophile

Jack L's picture


If I were to buy any audio, I would not read anything, specs & reviews irrespective. I always audition first with my own ears.

You may trust the measurement date & whoever critics' ears. Sorry, I trust my ear ONLY. period. Cause I pay with my hard-earned money.

Listening is believing

Jack L

Long-time listener's picture

Measurements can tell you important things, provided you understand how measurements match up with your personal taste and usage.

Measurements can also alert you to things that might become apparent later on but that you might not notice in a short audition, or when auditioning in a shop rather than your own home.

Learn to make measurements work for you. It will lead to better decisions in the end than listening alone. I bought my last two DACs (NAD M51; Topping D90SE) virtually on measurements alone, though I also read multiple reviews of the NAD. I loved it. When I saw that the Topping measured even better, I bought it. I love it too, and it's what I use now. I didn't have to listen or even read any reviews. Just saw the measurements.

The NAD M32 amplifier measurements looked good in some ways, but very strange in other ways. It sounded like crap. Those weird measurements should have raised questions in my mind, but unfortunately I trusted the reviewer. Again, measurements could have tipped me off ... if I'd paid attention.

Jack L's picture


Well, first off I never heard the sound of NAD M32 which tagged for $3,999. I do not know how good or bad it would sound.

Yet J.A. "highly recommended" it. Stereophine also recommended it as 2021 recommended D/A integrated amp.

You are comparing yr $899.99 Topping D90SE D/A with preamp out vs NAD D/A with built in integrated amp,

So apple vs orange ! It is a fair comparison ????

You blamed the crapy sound of NAD-M32 was due to its "very strange" measurement data.

You really think your ears were so powerful to hear the crappie sound of yr NAD M32 due to its "very strange" measurement data ??

So either there was a problem with the ears of yours or of J.A. who "highly recommended" it.


Long-time listener's picture

"You are comparing yr $899.99 Topping D90SE D/A with preamp out vs NAD D/A with built in integrated amp,"

I did not make any such comparison. Maybe you need to learn to read English as well as learning to read measurements.

Gavinspen's picture

My god in these times I have
Never come across such anal retention and obsessive compulsive
Material,billion dollar babies!
More money than sense,if this is musical enjoyment well I guess I've been blissfully unaware of a community obsessed by materialism and price.... shocking and the marketing equally ridiculous.Never feel guilty taking money from mugs
Chasing the unattainable.
Shameful capitalism and the same old
Reviews with all your reference recordings.

MatthewT's picture

Try harder.

Anton's picture

Can you expound further?

partain's picture

First time reader ?

remlab's picture

If Paradigm can get back to their roots of making speakers that measure good, surely B&W can. The large diameter mids drive me batty, and the tweeter? If Vivid can do a tapered tube with a flat response, I don't see why B&W can't.

Jack L's picture


What does "making speakers that measure good" to do with the same sounding good to our ears ??

Listening is believing

Jack L

PeterG's picture

I've enjoyed my 805 D3s--siblings not too far removed--for several years. But both the strengths and the challenges described above ring true to me. Thanks

Anton's picture

Very useful review, thank you.

Nirodha352's picture

“ … you need to audition”. No, I don’t. Nor any other model from this high-end pretender. I heard many models over the years and it is mid-fi at best. Still… spending a lot of advertisement money, will get you a “reasonably favourable review”. That I will give them.

Jack L's picture


Really ?????

So from yr having "heard many mdoels over the years", please enlight us on what brands/models YOU'd consider Hi-Fi.

Alas, I am still a PROUD owner & LOYAL lover of "mid-fi" loudspeakers. made in England. Too bad.

Listening is believing

Jack L

Nirodha352's picture

Hi Jack,
I also own an English speaker, the Kef 207/2. I have little desire to upgrade. Kef is what B&W would like to be but just doesn’t manage to become. If I were to upgrade I would like to get an Acapella speaker like the Atlas model. This seriously beats my kef. But Jack, I kind of regret my remark because it was never my intention to lessen someone’s choice of gear. Take care, enjoy our mutual hobby. I will too especially since we entered another lockdown here in the Netherlands as from today. Have a nice Christmas.
Cheers Wim

Jack L's picture


Sorry, I think we are not on the same page.

Now you've told us yr ideal loudspeakers are $117,500 Altas hybrid horn loudspeakers made in Germany vs $12,500 B&W cone loudspeakers made in England. 10 times price difference !!!!!

Like you were comparing a $121,000 Porsche 911 Carrea 4 with a Toyota Corolla !!! Major League ballgame with junior league !!!

For horn loudspeakrs ??? Thanks but no thanks for me, my friend.
I won't take any horn compressor driver speakers even for a penny !

Why? Compressor-driven horns get some distinct hornlike colouration. Any music will sound horny even a soprano! IMO. My skeptical ears get zero tolerance against tonal coloration.

Likewise, I prefer MM phono cartridges vs MC cartridges due to the distinct tonal colouration of MC cartridges.

Be my guest if you like horn loudspeakers. My skeptical ears just can't handle them.

Listening is believing'

Jack L

Jack L's picture


Right on, my friend.

Thanks but no thanks to the new extremely contageous variant
virus: Omnicron !

My entire city has entered again in lockdown this morning: indoor asssemby not over 10 people. Outdoor not over 25 !

What a shame !


tonykaz's picture

Are there any Audio Products that we don't need to audition ? ( I've liked every Magnapan design, so I'd guess that I probably wouldn't need to audition em if the price was right )

Paul at PS Audio is say'n their NEW loudspeakers are better than his IRS V5 that I think you once had some exposure to, I'm hoping you get to evaluate them and then recommend that we all go out to audition them.

You still own a pair of 801s after all these decades?, wow! Do you have the matching hoods that are kinda ugly ? I imported and sold those things, the 802s were farrrrrrrr more popular.

Tony in Florida

PeterG's picture

Hi Tony--

"You need to audition" is spot on--in two directions. You need to audition these because they are top tier speakers from one of the great names in hifi--your search would not be complete if you ignored them. But also--you need to audition because these speakers have characteristics that may be a problem for you--do not just accept them on reputation, caveat emptor.

mememe2's picture

A good stating point. A couple of questions though. First - which ear is it that you trust most , your left or right ear? Second. is your choice of ear predetermined by something as mundane as a hearing test- so that you know which ear to listen with?

Jonti's picture

I recently went for one. I have 1.7% hearing loss in my left ear and 0.9% loss in my right ear. This was something of a relief as it confirmed my instinctive bias to turn my head slightly to the left (thereby accentuating the quality of my reception) when listening in the sweet spot.

tonykaz's picture

We need to understand that a transducer system doesn't demand/require a blockBuster Powerhouse Amplifier fully capable of delivering considerable Current to loads down in the low impedance levels like the Thiel CS3s I used to sell. We had to demo those things with 200 horsepower Mono Amps that would double down in capability as they dropped below 4 ohms. Egads they sounded good with powerhouse Electrocompaniet Amplification but didn't do well with the Big Conrad-Johnson Premier Tube Amplifiers.

Measurements are critically important for people that can interpret the concept behind the design.

Mr.JA has consistently earned the "Audiophile of the Year" designation for these last 4 Decades. He might be a kind of Vanilla in the things he does and writes about but he's the best Vanilla we ever got.

Mr.HR, the Audiophiliac, Stereophile's Canadian writer and Mr.KM might be our up & Coming revealers of wonderful insights but we still need the technical matters properly described and contextually revealed.

Stereophile grew Into a great institution but without Mr.JA it probably would've just been another promotional Glossy
with glitzy snaps of Car Priced Record Players on the Covers.

Tony in Florida

Robin Landseadel's picture

Isn't it already?

John Atkinson's picture
tonykaz wrote:
Mr.JA has consistently earned the "Audiophile of the Year" designation for these last 4 Decades. He might be a kind of Vanilla in the things he does and writes about but he's the best Vanilla we ever got.

Thank you, Tony.

John Atkinson
Technical Editor, Stereophile

Anton's picture

I love to look at the last sentence of each measurement section JA1 writes and I read it as though Juan Antonio Samaranch is saying it. That sentence is JA's way of telling us what's really up.

Samaranch used to end each Olympics with a summary sentence that represented his view of how well the games went off. His schtick was...when giving the president's address at the close of each Summer Olympics, to praise the organisers at each Olympiad for putting on "the best ever" Games. But, he was fond of working in variations on that to give his true opinion, especially for 1996!

So, anyway, keep up the great work, JA1, will will continue to ruminate on each review's last sentence.

tyreman's picture

Methinks the pronounced treble or high frequencies still present, looks like fussy placement

reynolds853's picture

Opinions are like belly buttons, they say.

Specs and a reviewer's take are but two helpful inputs to consider. In this case, JA's perception was very close to mine (of the 804 d3 I own). I have disagreed with him on other reviews, but I have a ton of respect for him and his contributions.

I recently listened to the 804 d4 in a showroom and was less impressed in some ways vs the d3 but that should be expected because of the variables at play. The room setup at the store was not ideal.

I passed on several "flat" speakers and ended up with the "tailored" 804's. In my room, on my system, with my ears, at my listening levels and my recordings the 804's are simply amazing.

I look forward to the day we can look at specs and determine how something will sound (in our room?). In the mean time, I remain convinced there are qualities we simply have not figured out how to measure and enjoy the writings of guys like JA. I'm VERY glad all speakers don't sound the same. In the end, they are all pretty far from the real thing.

Happy Holidays, all.

Jack L's picture


Too true. But what better choice we music lovers will get instead of going to attend live concerts personally - time & money.

Considering the crazy pandemic going on worse & worse ! Public gathering is banned nearly everywhere.

Alternative is always something else from the real thing. Take it or leave it.

Jack L

BlackH20's picture

Finally, scientific measurements by Audio Science Review (ASR). Yes, all speaker wire is the same. Humans can't tell the difference between coat hanger wires and $1000 cables. Stereophile has endorsed snake oil for decades now. But Roger Russel of McIntosh said that 30 years ago, the audio rags couldn't turn down the ad money. So glad Amir puts these old subjective (financially endorsed) ears to rest. High prices and advertisements no longer rule the hobby, the JUDGE has finally arrived, and as we know, most of these reviews are crap.

reynolds853's picture

ASR has interesting information, yet their conclusions are no more or less reliable than any other. I purchased one of the most respected (Okto Research) and most panned (BorderPatrol) DAC's on ASR forums. You would think there would be a huge difference. There is not and I can not say for sure that everyone would pick the Okto DAC over the Border Patrol. My point is, use YOUR ears. ASR, unfortunately is no more the Rosetta stone than Stereophile. I respect the work of both but there are many more trolls on ASR who are convinced they know everything there is to know. At least Stereophile has some humility about what is "best."