Are MBL omnidirectional speakers worth the $$$?

[Purité Audio]

The polar response of the 90 in omni mode is illustrated and the results one can expect when using the speaker in this mode are explained.
Perhaps you are unfamiliar with the design?
Keith

 

[ShadowFiend]

FR response of Beolab 90 in omni mode is very rough, with a suddenly narrow from 300-1000 Hz, unlike the great implemetation in narrow and wide beam mode. So in my POV, that implementation of omni in Beolab 90 is garbage and if you using it to discriminate omni loudspeaker then your opinion is invalid also.

 

[Purité Audio]

I have heard the large MBLs on a number of occasions, the concept of pumping sound around a room to simulate the ‘live’ experience is for me simply wrong.
Keith

 

[Theta]

I have heard the large MBLs on a number of occasions, the concept of pumping sound around a room to simulate the ‘live’ experience is for me simply wrong.
Keith

The MBLs do not pump sound, they present music by musicians playing in a room, not in an isolation booth. The speakers you like are nothing more then headphones at various distance. People who want this kind of reproduction should listen through good headphone and save money on speakers. If one looks for perfect reproduction in speakers they will always be disappointed, Show me any speakers at any price point, I will find a fault.

 

[Purité Audio]

Every record with the same ersatz,faux presentation, if you want live musicians playing go to a concert.
Keith

 

[SIY]

Every record with the same ersatz,faux presentation, if you want live musicians playing go to a concert.
Keith

What makes that presentation more "ersatz" or "faux" than two speakers with forward lobes?

 

[Theta]

What makes that presentation more "ersatz" or "faux" than two speakers with forward lobes?

Your are forgetting the backward lobes and the side lobes. In most speakers one could reasonably argue that the drivers do not make the speaker. In the case of the MLB's, the driver does make the speaker.

 

[DanielT]

B&O state they are ideal for non critical listening and parties,

https://bangolufsenassistentgohe.blob.core.windows.net/manuals/SPEAKERS/BEOLAB_90/beolab_90_technical_sound_guide_version_9.pdf

Page 18.
Keith

What great speakers if you want:

 

[Sir Sanders Zingmore]

Every record with the same ersatz,faux presentation, if you want live musicians playing go to a concert.
Keith

I’m getting a sneaking suspicion that you don’t like MBLs

 

[thewas]

A lot of time and anger would be saved if instead of posting people would first search and read what has been written about the same topics in the past from persons who really know what they are talking about and take off their black and white glasses as most truths are somewhere in the middle, but it seems writing in forums is also a hobby for some.

Here are some quotes of Floyd Toole who even owned and enjoyed loudspeakers with close to omni radiation pattern:

Some thoughts:
1. I know of no real-life vocal or musical sound source that behaves like a point source. In fact, as shown in Figure 10.18 human voices and many musical instruments have directivities not unlike conventional forward firing loudspeakers. Humans, therefore, are well adapted to listening to the direct and reflected sound fields of such sources - not point sources. Approximations of point-sources are used to measure concert hall reverberation times (pistols, firecrackers, popping balloons, crudely "omni" loudspeakers) on the assumption that an entire orchestra will at different times radiate some sounds in all possible directions . . . or not. It is another of those "academic" notions that becomes a practical norm but which is not an accurate representation of what happens in life. At an Acoustical Society meeting a few years ago there were a few papers by academics who were measuring the omnidirectIonality of popping balloons. To me that is an indication that they were running out of thesis topics that had any potential to contributing to the useful body of knowledge.
2. As discussed, with measured evidence, in Chapter 5, the steady-state room curve at frequencies above about 500 Hz is well estimated from early reflections; first reflections from floor, ceiling and walls. This means that most of the physical energy is in those components, and that perceptions will be dominated by them. Sounds radiated in other directions encounter multiple surfaces and much longer propagation paths en route to ears and are substantially attenuated. Simultaneous and temporal masking will further reduce the audible contributions of those later sounds. As I have said, I know of no evidence that indicates an inherent superiority of "perfect" omnidirectIonality, even in horizontal and vertical planes.
3. Usually, and I assume in this discussion thread, the relative virtues of loudspeakers are evaluated in two-channel stereo. Adding the many reflections from omni loudspeakers is known to reduce the audibly stark illusion presented by hard panned L & R sounds - softening the images and reducing the impression of sound emerging from a monophonic point in space. Also, inevitably, the clarity of the "double-mono" phantom images, including the star performer in the center, is reduced. Some like this, some don't. But all of it exists because of the directionally and spatially deprived performance of stereo - which sadly we are stuck with as the musical norm. Some of us have moved on to multichannel enhancements of stereo, in which one can exercise some control over "reflections". Because timbre and localization are dominated by the direct sound, omnidirectional loudspeakers would not be advantageous.
4. Finally, until mixing and mastering engineers start using omni loudspeakers in somewhat reflective rooms the "circle of confusion" is aggravated when customers start editorializing on things at home. The art cannot be preserved. It is like buying an old master and illuminating it with colored light. Personal preference prevails, but at least the light can be turned off for others.

If I were to be able to return to the world of audio research I would work towards a better understanding of multichannel upmixing. Dr. David Griesinger, when at Lexicon did a superb job of stereo enhancement in the Logic 7 upmixer. It pretty much left the stereo soundstage alone while adding tasteful amounts of envelopment. In the best implementation it was adjustable. Sadly that is gone. Now I am experiencing Auro3D upmixing in an SDP-75 and at its best it is quite satisfying. It too is adjustable. It quickly becomes clear that no upmixing algorithm setting is satisfying for all program material. However, it also becomes clear that reverting to raw stereo is frequently a backwards step. The same is true of loudspeaker directivity patterns. Fortunately, humans are very adaptable.

I think you will find answers to your questions in the 3rd edition of my book. The beginning of Chapter 18 describes how I stumbled into a lifetime of psychoacoustic research by asking essentially the same question you did: "what is good sound, and is there agreement on the objective?" I had some advantages over most people. I had access to an excellent anechoic chamber in which to do measurements, although I did not know how to interpret the data beyond the most naive notions. I also arbitrarily chose to compare four loudspeakers at a time in an A, B, C, D fashion. My experience with my PhD project listening tests on sound localization taught me that loudness had to be equalized, presentations had to be randomized, and the tests had to be "blind". Having multiple loudspeakers in the comparison made the listener's task much easier, because very quickly timbral signatures of program material (constant) could be separated from timbral contributions of the loudspeakers (variable). This method has continued to this day.

Recordings are enormously variable, so what makes a good one? Here we must distinguish between a good "demo" recording and a revealing "test" recording. Years of listening to "audiophile" recordings tell me that most are in the "demo" category. Isolated clear voices with simple accompaniments are always included. From our observations over the years voices and solo instruments are not very revealing of timbral problems. We learned much later that bass quantity and quality account for about 30% of an overall subjective sound quality rating, so recordings with good bass extension are useful, and dense orchestration with some reverb assist in revealing coloration due to resonances. Much to our dismay, the classical repertoire did not distinguish itself, but pop/rock with high production values did.

Listeners could not possibly know what such studio recordings should sound like, so how could they make reliable, repeatable ratings of sound quality. It was not because they were recognizing excellence. It seems most probable that they were responding to unnatural "foreign" contributions to the recordings, by far the most common one being acoustical and mechanical resonances in the loudspeakers. By this reckoning, the "best" sound was in fact the "least bad" sound. "Perfection" is revealed when audible colorations are attenuated. This was confirmed in measurements, with the currently standardized "spinorama" being a presentation capable of describing enough of the sound arriving at a listening position to be able to calculate a trustworthy prediction of subjective ratings. Timbral neutrality, it seems, is a necessary starting point for loudspeaker design. Beyond that spectral balance matters, and this is the "tone control" region of equalization for variations in recordings and loudspeaker/room interactions.

Now, what about directivity. The notion that omnidirectIonality is somehow "ideal" awaits proof. As described in my book, I have enjoyed the sound from both omnis and conventional forward-firing loudspeakers. Recordings are not made with omni monitors, so their use is that of an embellishment - a "sound effect" that in some situations and with some program compensates for limitations of stereo. With multichannel recordings or tasteful multichannel upmixing of stereo material omnis cease to be advantageous. They do not, as has been claimed, have any "natural" sound connection. In fact all sound sources that matter to music lovers exhibit directivity similar to forward firing loudspeakers - see the illustration.

View attachment 249963

The closest I can come to answering this involves a personal experience. At the National Research Council we rented our facilities and services to industry, including in this case magazines. We conducted double-blind listening tests and performed anechoic measurements on products being reviewed by two Canadian audio magazines, now defunct (RIP). Among the products evaluated was the Mirage M1, possibly the first well-designed bipole loudspeaker. Over much of its frequency range it was close to being omnidirectional. When compared directly with conventional forward-firing loudspeakers in the (acoustically typical) listening room, it competed very well. Well enough that I bought a pair. My experience is described, with anechoic and room measurements in Section 7.4.6 of the 3rd edition. In my home (long gone) I had two listening rooms, a home theater and a large, irregularly shaped, high ceilinged classical music "concert hall". The omni M1s served well as a substitute orchestra in that space with me listening 22 ft away. I liked that space and that experience, but now I have an elaborate multichannel system that I would say is even better and much more flexible for stereo upmixes.

 

[SIY]

In fact all sound sources that matter to music lovers exhibit directivity similar to forward firing loudspeakers - see the illustration.

But the extra complication is that we've mashed the sources into two channels.

 

[TankTop]

Wow, a new scientific evaluation, Of course you are entitled to your opinion. Here is mine: Some of the speakers on you retail website are not even good enough for parties.

Oddly enough some of us still enjoy listening to music jsimply for the joy it brings us. Someday my hearing may evolve and I become a critical listener of speakers, I really hope not

 

[NTK]

But the extra complication is that we've mashed the sources into two channels.

Toole was addressing claims such as this one (link). If the directivity of the speakers and the instruments aren't similar, what are they trying to "emulate"? And as you said, so what if you can "emulate" the directivity of the instruments when everything is "mashed into two channels"?

And of course MBL's are not omni-directional, unlike what are suggested in their marketing materials. They can be at best symmetrical about their vertical axes (unlike what is suggested by the picture below), and certainly cannot have spherical symmetry (i.e. real omnidirectional).

Some more tidbits from Dr Geoff Martin of Bang & Olufsen (link).

 

[Ktacos]

What do you have in mind when you say serious or critical listening? Like professional applications? Or even for careful listening for enjoyment?

Omnis can operate full range in a system and have good frequency response, so I’m curious why to categorically rule them out.

For me, they don't really image.

 

[cavedriver]

To me this whole discussion goes back to discussions I remember reading in Stereophile and such back in the 90's, and has been timelessly debated everywhere in the audio reproduction world. It's the part of speaker measurement that is hardest to set a metric for and is a big chunk of the "30%" that we can't get from Klippel measurements and reviews because while things like the polar response can be measured, every recording and every listening environment are different.

Usually it is taken as a basis that we want as accurate and realistic an experience listening to a piece of music as could be had in any "live" setting. I mean, we obtained a "recording" of a "performance", so presumably we want to bypass the "recording" part and get directly to the performance. Initially we have to set aside all the music that is manufactured only in the recording (layered tracks, tracks recorded in pieces and assembled, synthesized outright, etc.), that is most pop music and a lot of other stuff. So then we ask- how did we perceive that live performance if we were standing there, and then how do we record it, and then, how to we play it back. I don't think it's worth repeating the whole discussion here, although NTK just posted a useful primer above.

My point is this- in the specific case of the MBL's we are exploring the question of how much the room should contribute to the original heard experience, can contribute to the experience, and unavoidably will contribute to the experience. In Purite's example, we could build that idealized listening room of a chair on a post in free space and speakers placed around them in a 360 arrangement (well, really spherically around them). Of course this music would then need to be recorded with a "head" that has located microphones spherical around it to capture the incoming sound in the precise proportions.

But of course none of this is practical. And from there we land on tens of different compromises- recordings with 1, 2, 3, 4, 5 or more channels, manufactured channels, the rooms we actually listen in, the number of speakers in the room, producers that mix for 2-channel playback and average rooms, vs mix for the raw sound and let the user's environment modify it. Which of course brings us back to the wealth of music that could never have been heard "live" in the first place because it was manufactured. Basically every studio album made since the advent of 2-channel music production. Effects like reverb are added to virtually every rock track (see at 7:55 in the video below), in part to replace the "natural reverb" of resonant live listening venues like churches and concert halls. These recordings were never meant to be heard "live" initially, but instead are created with the expectation that it will be reproduced in a typical listening environment with walls, ceilings, and floors. So in one recording we want more room contribution because the recording doesn't have it, but in another there is already plenty in there and minimal room contribution is preferred.

I don't think there can be a right answer here unless we can control the original recording of the music, which we clearly don't want in the case of pop, or even in the case of Solti's recording of Wagner's the Ring, where the 2 channel recording benchmark was first set for taking a classical piece and removing the "live" element from the basis. Unfortunately, I think this debate has to remain a point of preference, or at least a recording-specific assessment that we haven't reached as a review and measurement tool yet.

 

[SIY]

I've only heard the MBLs at shows with the exhibitor choice of source material and volume, so can't render an experience-based opinion. What I heard ranged from very good to horrible (nothing to do with the polar pattern, they were just way too loud with a heavily tipped-up bass). But... I'm open to the idea that they might give a good presentation.

In my own system, I have two sets of speakers that fall outside of the "forward lobe with controlled directivity" paradigm and TBH, I haven't heard anything yet I'd replace them with. So I'm far less than dogmatic about there being a singular right way to manage polar patterns given the massive data compression involved in two channel audio. The reigning paradigm has resulted in some excellent sounding speakers, but it's not the only way to achieve excellence.

 

[Theta]

A lot of time and anger would be saved if instead of posting people would first search and read what has been written about the same topics in the past from persons who really know what they are talking about and take off their black and white glasses as most truths are somewhere in the middle, but it seems writing in forums is also a hobby for some.

Here are some quotes of Floyd Toole who even owned and enjoyed loudspeakers with close to omni radiation pattern:

I've only heard the MBLs at shows with the exhibitor choice of source material and volume, so can't render an experience-based opinion. What I heard ranged from very good to horrible (nothing to do with the polar pattern, they were just way too loud with a heavily tipped-up bass). But... I'm open to the idea that they might give a good presentation.

In my own system, I have two sets of speakers that fall outside of the "forward lobe with controlled directivity" paradigm and TBH, I haven't heard anything yet I'd replace them with. So I'm far less than dogmatic about there being a singular right way to manage polar patters given the massive data compression involved in two channel audio. The reigning paradigm has resulted in some excellent sounding speakers, but it's not the only way to achieve excellence.

Please tell what are the 2 sets of speakers.

 

[Theta]

A lot of time and anger would be saved if instead of posting people would first search and read what has been written about the same topics in the past from persons who really know what they are talking about and take off their black and white glasses as most truths are somewhere in the middle, but it seems writing in forums is also a hobby for some.

Here are some quotes of Floyd Toole who even owned and enjoyed loudspeakers with close to omni radiation pattern:

I have read Mr.Tool's books. He points out correctly every aspect of electro acoustic theory and their pluses and minuses in technical detail, However he has not shown any plans or advice for a design theory or approach that would satisfy everyone. Even his own system testifies to that. To me labeling MBL's as omnis automatically brings on preconceived opinions. Why can't you measure them, listen and judge them as you would any speakers?
I am going to audition an MBl system this week end to see if memory serves.

 

[ahofer]

It's true that instruments are not point sources, but when you consider the directionality of the strings and woodwinds in an orchestra, it's all over the place and depends on setup. And that's before you consider the microphone (thus speaker) position, which is often well above the parquet and far forward of the balcony.

 

[thewas]

I have read Mr.Tool's books. He points out correctly every aspect of electro acoustic theory and their pluses and minuses in technical detail, However he has not shown any plans or advice for a design theory or approach that would satisfy everyone. Even his own system testifies to that.

Your posts and especially above show that you definitely have not read his book (it is one book with just revised editions). Toole's book is full of advice how to improve sound reproduction based on research which was done not just on theory but with listening tests.

To me labeling MBL's as omnis automatically brings on preconceived opinions.

?? Why shouldn't someone name them so when they name themselves "The World Exclusive Omnidirectional Radialstrahler Loudspeakers"

High End Radialstrahler Loudspeakers from MBL

Finally experience music instead of just listening to it - with the Radialstrahler Speakers from MBL. What technology leads to this impressive music experience? Read all about the innovative speakers from MBL here.

www.mbl.de

Why can't you measure them, listen and judge them as you would any speakers?

As written in my above quotes Toole not only listened, measured and judged omnis but even owned some loudspeakers which showed mainly omni behaviour.