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Beolab 28

Hephaestus

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Would be interesting to see how they implemented the variable directivity with just using 3 full range drivers and one tweeter (plus a woofer of course) and some corresponding measurements.
As shown on the site linked, they used a motorised mechanism that opens or shuts the wooden vertical louvers.
 
There's one word that sh#ts me more than anything these days:

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I’ve been waiting for these speakers for some time now but my goodness did the price end up being a lot higher than I had hoped: “The Beolab 28 with fabric covers is $14,750 (€10,750/£9,750) while the wood cover option is $16,500 (€12,000/£10,750) — for a pair.”

I mean yes this is Bang & Olufsen we’re talking about, but I’ve been a B&O customer for some time now and this is very high even by their standards for what is typically their slightly more approachable “tall and slender floor standing active speakers” series.

Granted it does have more tech than what we’ve seen in previous speakers; I do love that you can finally just play to them directly via Bluetooth and AirPlay (no external DAC and Network Streamer needed). There’s also some form of “Active Room Compensation” with a microphone built into each speaker, but can anyone chime in on how effective this is (calibrating from the speaker’s position)? From what I can tell there’s no option to do a calibration from your actual listening position, so this does seem somewhat limited.
 
I think it would work 50/50-ish... For lower frequencies, which they limited the correction to, you either:
  • sit in a peak and the speaker as well > eq solves the peak pretty well
  • sit in a peak but the speaker does not > bad luck, peak remains.
  • do not sit in a peak, but the speaker does >
    • you could be in an null area > reducing energy put in by the speaker doesn't change the fact you sit in the null (nothing much changes, the result is still a ~null)
    • you could be in the exact middle between peak and null > you were lucky, correcting the peak at speaker location now makes level too low at listening position.
    • anything in between > you fix some, you worsen some.
  • you sit in an null, so does the speaker > no eq helps here. Problem remains, still a null.
Score overall: It solves peaks pretty well, nulls aren't fixable by EQ, and in between trade places between better or worse after eq.
Hack in a symmetrical room: place yourself exactly as far from the back wall as the speakers are away from the front wall. This way the chance is bigger you are in the same peaks. See 3D representation here and look at low freq room modes.

The technical sound guide by B&O is actually very informative and honest(!) about the limitations of mitigating technologies they developed. It clearly states placement and room acoustics play a vital role.
 
I think it would work 50/50-ish... For lower frequencies, which they limited the correction to, you either:
  • sit in a peak and the speaker as well > eq solves the peak pretty well
  • sit in a peak but the speaker does not > bad luck, peak remains.
  • do not sit in a peak, but the speaker does >
    • you could be in an null area > reducing energy put in by the speaker doesn't change the fact you sit in the null (nothing much changes, the result is still a ~null)
    • you could be in the exact middle between peak and null > you were lucky, correcting the peak at speaker location now makes level too low at listening position.
    • anything in between > you fix some, you worsen some.
  • you sit in an null, so does the speaker > no eq helps here. Problem remains, still a null.
Score overall: It solves peaks pretty well, nulls aren't fixable by EQ, and in between trade places between better or worse after eq.
Hack in a symmetrical room: place yourself exactly as far from the back wall as the speakers are away from the front wall. This way the chance is bigger you are in the same peaks. See 3D representation here and look at low freq room modes.

The technical sound guide by B&O is actually very informative and honest(!) about the limitations of mitigating technologies they developed. It clearly states placement and room acoustics play a vital role.

Thank you kindly for your detailed response to my question. Very much appreciated!
 
Would be interesting to see how they implemented the variable directivity with just using 3 full range drivers and one tweeter (plus a woofer of course) and some corresponding measurements.

As shown on the site linked, they used a motorised mechanism that opens or shuts the wooden vertical louvers.

The "curtains" are not handling for the directivity control, they are just an optical gimmick to visualize the directivity mode. There are also fabric curtains available and they can be controlled manually without changing the directivity mode.


"Beam Width Control" @ B&O 28:

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When the recording calls for it, those low frequencies are substantial and go from 27 Hz up to 200 Hz, when the single 6.5-inch woofer, employing a ferrite magnet and a coated paper cone, bows out and lets the three full-range drivers take over the heavy lifting. These 3-inch transducers, which use neodymium magnets and paper cones, cover the lion’s share of the audio spectrum. In the spirit of an omnidirectional design, one driver is frontally placed circa ear level, with an additional driver on the left and right side, above and below the center driver. A single 1-inch tweeter, using a neodymium magnet and a textile dome, is situated above the full-range center driver and carries on business from 4,000 Hz up to 23,000 Hz.

That versatility is a result of the speaker’s Beam Width Control, which optimizes the listener experience depending on setting. In the Narrow directivity mode, the three full-ranges are used from 200 Hz to 4,000 Hz, so driver output favors a listener sitting in front of the speakers, without the interference of side and rear wall reflections. This is where “serious” listening will be done, and the Beolab 28 rewards just that. In Wide mode, the sonic stage diffuses to maintain a natural tonal balance to the side or when moving about the room, as one might experience in a social setting with more than a listener or two. Here, the front-mounted full-range is still used from 200 Hz to 4,000 Hz and the side-mounted full-ranges are used all the way up to 15,000 Hz, albeit at a lower level at the higher frequencies.

Review: Bang & Olufsen’s Wireless Beolab 28 Loudspeakers Look as Otherworldly as They Sound (yahoo.com)
 
I think it would work 50/50-ish... For lower frequencies, which they limited the correction to, you either:
  • sit in a peak and the speaker as well > eq solves the peak pretty well
  • sit in a peak but the speaker does not > bad luck, peak remains.
  • do not sit in a peak, but the speaker does >
    • you could be in an null area > reducing energy put in by the speaker doesn't change the fact you sit in the null (nothing much changes, the result is still a ~null)
    • you could be in the exact middle between peak and null > you were lucky, correcting the peak at speaker location now makes level too low at listening position.
    • anything in between > you fix some, you worsen some.
  • you sit in an null, so does the speaker > no eq helps here. Problem remains, still a null.
Score overall: It solves peaks pretty well, nulls aren't fixable by EQ, and in between trade places between better or worse after eq.
Hack in a symmetrical room: place yourself exactly as far from the back wall as the speakers are away from the front wall. This way the chance is bigger you are in the same peaks. See 3D representation here and look at low freq room modes.

The technical sound guide by B&O is actually very informative and honest(!) about the limitations of mitigating technologies they developed. It clearly states placement and room acoustics play a vital role.

I could see a more advanced implementation of it beyond merely measuring FR working. Instead of focusing on FR, use the test signals to calculate the room dimensions and the relative positioning of the speakers (i.e. sonar), then calculate the resultant modal behaviour and correct. But I'd expect only a company like Apple could even come close to the expertise of integrating this (Homepod seemed to use sensors for boundary compensation, but this'd be the next level).
 
I could see a more advanced implementation of it beyond merely measuring FR working. Instead of focusing on FR, use the test signals to calculate the room dimensions and the relative positioning of the speakers (i.e. sonar), then calculate the resultant modal behaviour and correct. But I'd expect only a company like Apple could even come close to the expertise of integrating this (Homepod seemed to use sensors for boundary compensation, but this'd be the next level).

Why not just use a phone to calibrate?
 
I heard these today at at B&O shop. I perceived them as rather remarkable. To my ears they had an insane dynamics and immediacy for such diminutive floorstanders, and tonality and timbre was spot on. Narrow mode was much sharper and clearer (just like with Beolab 50 and 90), but wide mode was better for social and relaxed listening outside the sweetspot. They reminded me very much of Beolab 50 in their overall "feel", even though they obviously can't match the slam and weight of the Beolab 50.

Sure, they are very pricey, but I do think that this is much more than a lifestyle speaker. I liked these babies better than I liked the Kii Three and the D&D 8C - which may also have to do with the fact that they are so pleasing to the eye, of course. No direct comparison though, and all sighted and based on unreliable long-term audio memory, so take these sighted impressions with many grains of salt!

Another cool thing is that one can stream directly to them, and they do room compensation directly in the speaker/app. So no further boxes or thingies needed.

Anyways: I'm really impressed by what B&O has achieved here.
 
Here is what the SPeaker Looks like:

Photos:
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beolab-28-stereo-speakers-by-bang-olufsen.jpg


Thanks to Lucksus sound for the images. And Banging Olsen.


I know they cost a good amount of money. This is art. And it's Art that you can use.
Its more like buying a sculpture in my opinion. Almost everything that they make is something of a statement piece.
 
I'm seriously thinking about selling all my gear and buying a pair. They look beautiful and supposedly sound great. Plus, I'm getting fed up of the never ending cycle of swapping/upgrading DACs, AMPs, speakers, and all the cables are doing my head in!

I share your approach to keep the setup as simple as possible -> Less, but better!
In general I try to buy reliable and long lasting components which do not need a lot of accessories (as speakers I own Genelecs). I guess the best way to audio happiness is to buy a setup you like and then stay away from forums or even better the whole world of audio equipment...
 
I'm just trying to figure out the best way to connect the speakers to Roon and my two analogue sources (Nagra IV-S and Revox B77 mkII). I'm thinking about connecting directly to the Roon Rock PC (with USB->SPDIF converter), and then using the 3.5mm line in for the analogue devices using some type of switch.
 
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