B&W 800D4 series

[Purité Audio]

There is quite an interesting ‘history of B&W’ video, it says that the success of the original 801 allowed the building of the ‘Steyning research centre’ ( Steyning is a town is Sussex where B&W are based, presumably that research centre has been abandoned.
Keith

 

[Svend P]

This quote could use more explanation:
"but it will need extra care in setup and system matching."

So they need an amplifier that isn't bright sounding? Do those exist?

 

[Ageve]

The nearfield response is… interesting.

Bowers & Wilkins 805 D4 Signature loudspeaker

The "Bowers" in the name of British manufacturer Bowers & Wilkins (B&W) refers to founder John Bowers, whom I got to know fairly well before he passed in 1987. In recent years, I've reviewed two Bowers & Wilkins loudspeakers: the 705 Signature two-way standmount in the December 2020 issue and...

www.stereophile.com

 

[Matias]

Maybe pointing those tweeters 90° to the sides to attenuate the treble in the listening position lol .

 

[Art Vandelay]

Measurements of the 801 D4 by the German magazine "stereo", FWIW:

• FR limited to 30Hz .. 20 kHz
• red = on axis, blue = 30 degree horizontal off axis

View attachment 158460

I recently acquired a DEQX HDP-5 processor, and my next project is to correct some of the B&W800 issues.

Phase 1.

1. Drive the woofers directly from the DEQX LF outputs (via NC1200 mono amps), using DEQX LP filters. This requires bypassing the internal passive crossovers.

2. Drive the FST mids from the DEQX using the existing B&W passive crossovers. NCX500 mono amps will be used here.

3. Drive the tweeters from the DEQX HF outputs using the existing passive crossovers via high quality class AB amplifiers
* with 0.15mS delay correction and polarity inversion applied from DEQX.

Action 3. is significant, because it time aligns the tweeter and FST mid, resulting in phase coherence above and below the crossover frequency.
This will remove the peak around 4kHz and also remove the dips above and below, and particularly the dip around 2kHz, and especially off axis where phase between drivers approaches 180 degrees. The power response will be much improved.

I'm not 100% sure how or why B&W engineers arrived at their x-over design, but I suspect that part of the reason to move the tweeter 0.5 wavelength forward was to eliminate potential interference effects. Their white paper also refers to subjective tests and a preference for absolute driver phase.

The above configuration will also give me the flexibility to match driver sensitivity, resulting in a flatter response overall.
Fwiw, I have already performed comprehensive measurements including individual driver measurements and run simulations etc, so I can go ahead with some confidence.


Phase 2 will involve a more complete active drive using linear phase filters and optimising crossover frequencies.

I'll return here from time to time to post measurements etc.. The entire process is likely to take weeks or months.

 

[A Surfer]

I recently acquired a DEQX HDP-5 processor, and my next project is to correct some of the B&W800 issues.

Phase 1.

1. Drive the woofers directly from the DEQX LF outputs (via NC1200 mono amps), using DEQX LP filters. This requires bypassing the internal passive crossovers.

2. Drive the FST mids from the DEQX using the existing B&W passive crossovers. NCX500 mono amps will be used here.

3. Drive the tweeters from the DEQX HF outputs using the existing passive crossovers via high quality class AB amplifiers
* with 0.15mS delay correction and polarity inversion applied from DEQX.

Action 3. is significant, because it time aligns the tweeter and FST mid, resulting in phase coherence above and below the crossover frequency.
This will remove the peak around 4kHz and also remove the dips above and below, and particularly the dip around 2kHz, and especially off axis where phase between drivers approaches 180 degrees. The power response will be much improved.

I'm not 100% sure how or why B&W engineers arrived at their x-over design, but I suspect that part of the reason to move the tweeter 0.5 wavelength forward was to eliminate potential interference effects. Their white paper also refers to subjective tests and a preference for absolute driver phase.

The above configuration will also give me the flexibility to match driver sensitivity, resulting in a flatter response overall.
Fwiw, I have already performed comprehensive measurements including individual driver measurements and run simulations etc, so I can go ahead with some confidence.


Phase 2 will involve a more complete active drive using linear phase filters and optimising crossover frequencies.

I'll return here from time to time to post measurements etc.. The entire process is likely to take weeks or months.

I would be very interested in the outcome for sure. I hope that it goes well.

 

[Ashl777]

Anyone have experience with the bowers and wilkins 800 matrix with the d appolo arrangement?

 

[sigbergaudio]

Not sure if these magazines measure directly on-axis at tweeter height, but the 800/801 speakers are so tall that I doubt anyone have the tweeters at ear height. So listening will be somewhat off-axis, and probably more neutral than it looks in these graphs.

 

[DSJR]

The demo units I've seen, tend t have the N800 series pointing straight ahead - same with most PMC speaker dems, so maybe these companies are now pure;ly following their usually older owners?

 

[MediumRare]

The demo units I've seen, tend t have the N800 series pointing straight ahead - same with most PMC speaker dems, so maybe these companies are now pure;ly following their usually older owners?

B&W explicitly recommends NOT toe-ing in certain speaker models. Not only do you get intentionally smoother FR, you get excellent soundstage width and precision simultaneously.

 

[Ashl777]

B&W explicitly recommends NOT toe-ing in certain speaker models. Not only do you get intentionally smoother FR, you get excellent soundstage width and precision simultaneously.
View attachment 451633

Would this be relating to d series speakers ? Diamond 1,2,3,4 ? Or older nautilus or matrix 800?

 

[Ageve]

B&W explicitly recommends NOT toe-ing in certain speaker models. Not only do you get intentionally smoother FR, you get excellent soundstage width and precision simultaneously.

I don't know where you found that picture, but it's not from the user manual of any 800 series speaker I've seen.

This is from the 800 D4 manual:

From the same manual:

This is their speaker placement guide:

Blog - Hi-Fi Essentials – How to set up a loudspeaker | Bowers & Wilkins

In the third part of our series explaining the fundamentals of putting together a great Hi-Fi system, we look at how to get the best performance from your loudspeakers.

www.bowerswilkins.com

edit: Another guide:

Blog - Buying Advice | Bowers & Wilkins

If you’re about to buy a new hi-fi or chasing the best possible sound from components you already own, you need to read this. Our expert audio advice tells you everything you’ll need to know.

www.bowerswilkins.com

 

[Ashl777]

Sound is a mystery sometime. Had a pair of very expensive mcintosh xrt2k line array speakers. Had 32 postions. Was about to give up. Then placed them outside the magical triangle. Pointed them in much more ( opposite to manufactures specs) and viola, imaging popped and got a 3d soundstage like no other

 

[MediumRare]

The diagram I posted is from my 803 Nautilus/804 Nautilus manual. My advice is to start with that and measure with REW. Then toe in about 6 degrees (1/8th of the way from a line straight ahead toward the PLP) and measure again. If it looks like a small improvement try again (1/4th of the way) and measure. Then listen to a few tracks before moving more. For me the 6 degrees was the best solution.

 

[Ageve]

Well, your speakers are 27 years old. They were designed by Laurence Dickie just before he left B&W to start his own company (Vivid Audio).

Fortunately (for you), they have nothing in common with ”modern” Bowers & Wilkins speakers.

The recommendations in the user manual were the same though.

 

[MediumRare]

Well, your speakers are 27 years old. They were designed by Laurence Dickie just before he left B&W to start his own company (Vivid Audio).

Fortunately (for you), they have nothing in common with ”modern” Bowers & Wilkins speakers.

The recommendations in the user manual were the same though.

View attachment 451685

View attachment 451686

Mine aren’t that old but they still sound amazing with two Rythmik F12 subs. But the principle is the same with any speaker that seems bright and has smooth directivity within +/-20 degrees.

 

[Paxilexifaxi]

They are setup temporarily at my job to break in. Amps are conditioned by Niagara 5000, power cables are blizzards from amp to 5000 and tornado HC from 5000 to wall outlet. Speaker cables are thunderbird and Thunderbird bass. Xlr cables from preamp to amps.View attachment 225693View attachment 225681

I'm not 100% sure, but I believe I saw a nearly identical pair of Bowers & Wilkins speakers some time ago from a private seller – at least visually.

The cabinet shape and color looked very similar to the speakers shown in the picture here in the thread, but they were noticeably more compact.
The seller mentioned a price of around €8,000 per pair at the time.

My question:
Which smaller B&W model could this have been – with a similar cabinet design and matching finish on both the enclosure and drivers?
Or is there a more compact model in this price range that visually closely resembles the larger series?

 

[Ashl777]

I'm not 100% sure, but I believe I saw a nearly identical pair of Bowers & Wilkins speakers some time ago from a private seller – at least visually.

The cabinet shape and color looked very similar to the speakers shown in the picture here in the thread, but they were noticeably more compact.
The seller mentioned a price of around €8,000 per pair at the time.

My question:
Which smaller B&W model could this have been – with a similar cabinet design and matching finish on both the enclosure and drivers?
Or is there a more compact model in this price range that visually closely resembles the larger series?

Yes that would be the smallest /bookshelves 805 or if floorstander can be 804 or 803. The larger ones are 802 , 800/801

 

[Ageve]

Erin has measured the HTM81 D4, and as expected, it has the same Batman sound as the rest of the D4 series:

Bowers and Wilkins HTM81 D4 Center Channel Speaker Review

Bowers and Wilkins HTM81 D4 Center Channel Review

www.erinsaudiocorner.com

Horizontal directivity is also poor for a 3-way design:

Revel C426Be as a comparison:

Revel C426Be Center Channel Speaker Review

Revel C426Be Center Channel Review

www.erinsaudiocorner.com