omnidirectional loudspeakers = best design available

[youngho]

My actual words: “he needed a loudspeaker that was really bad at soundstage reproduction and greatly blurred the sonic image”

Interesting subjective review: https://www.stereophile.com/content/mirage-m-1-loudspeaker-page-3

"Imaging is quite specific and, even more important, realistic. The individual ambiences of each instrument are correctly attached in space to the actual instrument. Rather than a creative act on the part of the speaker, it seems to me that the M-1 is simply letting you hear things that are more disguised with other speakers. If the Mirage euphonically adds a bit of soundstage, I am unfortunately not the Stereophile reviewer best equipped to pick up this characteristic; those like JGH and JA, who can review with recordings they themselves have made, are. I can only say I hear nothing phony."

Also: http://www.hifi-review.com/153726-mirage-m-1.html

"What DSL's test results do not indicate-and, indeed, what no lab measurements presently made anywhere can show directly-is the sonic image conveyed by the M-1s. And that can be described in a word that comes right out of Kubrick's movie title: space. As the product brochure puts it, "� the speakers just seem to disappear." With some classical program material, a sonic stage of such convincing and realistic depth is produced that you might think an ambience-recovery/generation system were operating. Large orchestras sounded especially good. An outstanding, close-miked classical piano recording (Beethoven sonatas on Denon CO-2203) almost had me believing that the instrument was in the room. The sonic stages for various types of pop music also floated free of the speakers to produce some interesting and very pleasant effects."

"As far as I can hear, the M-1 has only three sonic drawbacks, none of them very serious. First, the tweeter, being about 4-1/2 feet above the floor, is above the ear level of a seated listener; even the front-panel woofer is 2-3/4 feet off the ground. The basic stereo image, therefore, is elevated, and for some types of music and recordings this is simply unrealistic, as is the slight change in image elevation as some instruments change musical registers. Second, the stereo image itself is not as razor-sharp as I have lately been hearing from some conventional front-radiating speakers. Then again, this slight image fuzziness is also typical of omnidirectional and quasi-omnidirec-tional loudspeakers. The M-1 compensates for image imprecision with image solidity and maintains a properly distributed sonic stage even as you move around the room. Besides, I find the present-day mania over pinpoint imaging itself a bit unrealistic: Most live music doesn't present nearly so precise a soundstage."

I haven't had the pleasure of hearing them, but "REALLY BAD AT SOUNDSTAGE REPRODUCTION AND GREATLY BLURRED THE SONIC IMAGE"

 

[Blumlein 88]

Do we really gain anything by going on the big circle of a bad room Toole had once and what he did about it?

A friend of mine once had to use a room that was completely square. It was a truly horrendous sounding room that he never tamed. Had we figured out how to get that room to work out would have little utility for other better rooms.

So can you guys drop the quoting of the Toole book liked it's a religious text, and contribute something worthwhile or just move on?

 

[whazzup]

More thinking aloud:
I've heard amazing binaural recordings on youtube. Will that kind of recording setup (and measurements?) help show the difference between direct firing versus dipole/bipole/omni setups?

 

[Blumlein 88]

Interesting subjective review: https://www.stereophile.com/content/mirage-m-1-loudspeaker-page-3

"Imaging is quite specific and, even more important, realistic. The individual ambiences of each instrument are correctly attached in space to the actual instrument. Rather than a creative act on the part of the speaker, it seems to me that the M-1 is simply letting you hear things that are more disguised with other speakers. If the Mirage euphonically adds a bit of soundstage, I am unfortunately not the Stereophile reviewer best equipped to pick up this characteristic; those like JGH and JA, who can review with recordings they themselves have made, are. I can only say I hear nothing phony."

Also: http://www.hifi-review.com/153726-mirage-m-1.html

"What DSL's test results do not indicate-and, indeed, what no lab measurements presently made anywhere can show directly-is the sonic image conveyed by the M-1s. And that can be described in a word that comes right out of Kubrick's movie title: space. As the product brochure puts it, "� the speakers just seem to disappear." With some classical program material, a sonic stage of such convincing and realistic depth is produced that you might think an ambience-recovery/generation system were operating. Large orchestras sounded especially good. An outstanding, close-miked classical piano recording (Beethoven sonatas on Denon CO-2203) almost had me believing that the instrument was in the room. The sonic stages for various types of pop music also floated free of the speakers to produce some interesting and very pleasant effects."

"As far as I can hear, the M-1 has only three sonic drawbacks, none of them very serious. First, the tweeter, being about 4-1/2 feet above the floor, is above the ear level of a seated listener; even the front-panel woofer is 2-3/4 feet off the ground. The basic stereo image, therefore, is elevated, and for some types of music and recordings this is simply unrealistic, as is the slight change in image elevation as some instruments change musical registers. Second, the stereo image itself is not as razor-sharp as I have lately been hearing from some conventional front-radiating speakers. Then again, this slight image fuzziness is also typical of omnidirectional and quasi-omnidirec-tional loudspeakers. The M-1 compensates for image imprecision with image solidity and maintains a properly distributed sonic stage even as you move around the room. Besides, I find the present-day mania over pinpoint imaging itself a bit unrealistic: Most live music doesn't present nearly so precise a soundstage."

I haven't had the pleasure of hearing them, but "REALLY BAD AT SOUNDSTAGE REPRODUCTION AND GREATLY BLURRED THE SONIC IMAGE"

The M1 and M3 were sort of the opposite of the LS 3/5a. Rather than solid specific tiny holographic imaging they had big solid amorphous imaging. Great for orchestral music, merely ok for tight chamber music.

 

[Newman]

Do we really gain anything by going on the big circle of a bad room Toole had once and what he did about it?

A friend of mine once had to use a room that was completely square. It was a truly horrendous sounding room that he never tamed. Had we figured out how to get that room to work out would have little utility for other better rooms.

So can you guys drop the quoting of the Toole book liked it's a religious text, and contribute something worthwhile or just move on?

I’m with you, 100%. That was the only point I wanted to make (your middle paragraph about little utility). The pedantic carry-on has been unedifying IMO. My point, about that speaker and that room stands. My use of superlatives does not reverse or disprove my point.

Happy to move on.

 

[Newman]

Can you please provide a specific reference or quotation of what you say that Toole said? In your words, "the universal rules that I use" and "quote marks for Toole’s words, otherwise they are mine,"

Sure, since you asked nicely. And I quote Toole, “Of course directivity matters. It changes the temporal and directional patterns and sound quality of early reflections in a room. Horns of any directivity can be well behaved, or not, so generalizations are unsafe. In terms of sound quality, it seems that the constancy or smoothness of change in DI is more important than the DI itself. The dominant effect is spatial, not timbral. There is much discussion of this in forums, and personal preference is a factor. Stereo is so limited in its capabilities to convey spatial/enveloping sound that this is where it matters most. I use mutlichannel upmixing of stereo sources, so this factor fades to insignificance.”

The rest of your enquiries and comments, I will let pass, on the assumption that we are moving on like adults.

cheers

 

[Duke]

Newman, thank you. I appreciate your making the effort.

The room

My actual words: “Bad room... horrendous, virtually a giant echo chamber that just plain sounded bad....”

Toole’s actual words: “I built the largest concert hall that I could.... a very open living/dining room.... sparse furnishings.... a lot of glass windows.... (Newman: and some acoustic treatments IMO aimed at concert hall acoustics).... a parade of loudspeakers went through that room, and all disappointed.”

Comment: I don’t see anything wrong with describing a room that makes a ‘parade’ of loudspeakers sound bad, as a bad room for audio playback. That’s a fair definition of a room that is not suited to audio playback: it doesn’t work well with loudspeakers — presumably good loudspeakers, designed for audio playback. It was designed to be something else, a “concert hall” quote/unquote, and from that point onwards it was about finding speakers that could live in it.

From the long paragraph on Page 189, the same one your "Toole's actual words" above come from:

"I had concluded that two stereo loudspeakers needed help in delivering a credible enveloping concert hall experience, so I build the largest concert hall that I could afford at the time... [one sentence about the room shape]... Only two significant parallel surfaces remained, and those posed the only, easily solved, problem... [five more sentences describing physical aspects of the room, and an RT of about .5 seconds]... Acoustically it was a pleasant space to be in." [emphasis Duke's].

It sounds to me like Toole liked the room and it just needed the right speakers... speakers which, in that room, "simply 'became' the orchestra."

So I guess you and I have read the same thing and came away with completely different ideas about what it says. I don't see him saying or implying that it was a "bad room... horrendous, virtually a giant echo chamber that just plain sounded bad..." If you do, well then I propose that we agree to disagree.

And to round off, where did I say that Toole said that the room is sonically poor?

Right here:

he [Toole] wrote that he had (mis?)-conceived of a listening room in his home that turned out to be horrendous...

[emphasis Duke's]

The speakers

My actual words: “he needed a loudspeaker that was really bad at soundstage reproduction and greatly blurred the sonic image”

Toole’s actual words: “some blurring and expansion of the soundstage was needed”

Comment: no doubt I exaggerated...

"Blurring and expansion of the soundstage" describes the phenomenon of increased "Apparent Source Width", or ASW, and it is not obvious to me that this increase in ASW is a negative thing in Toole's mind, ESPECIALLY within the context of his statement that "They [the Mirage M1's in that room] simply 'became' the orchestra." ASW does come with tradeoffs, as do many things in home audio.

 

[Duke]

Do we really gain anything by going on the big circle of a bad room Toole had once and what he did about it?

Just for the record, Toole NEVER SAID that his room was bad. Newman did, and I disputed that. I realize it's tedious to watch people squabble over things that don't matter to you, but maybe it's over.

Happy to move on.

Finally something we can agree on. LIKE!!

I've heard amazing binaural recordings on youtube. Will that kind of recording setup (and measurements?) help show the difference between direct firing versus dipole/bipole/omni setups?

We intend to find out the answer to that question this year.

 

[Newman]

"This allows the brain to give primary attention to the earlier arriving direct sound from the loudspeakers, if the reflected sound streams have similar timbre and spectral content as the direct sound. " (http://www.linkwitzlab.com/listening_room.htm)

"The different room reflection patterns due to the different polar responses become perceptually fused with the direct sound of the loudspeakers, if the reflections are sufficiently delayed and if their spectral content is coherent with the direct sound." (http://www.linkwitzlab.com/AES123-final2.pdf)

"Hearing stereo is an auditory illusion, which is derived from cues in the loudspeaker and room signal streams, from memory patterns and adaptation to the acoustic environment (Avoid to give misleading cues due to cabinet diffraction, panel and cavity resonances, nonlinear distortion and spurious noises) 4) The auditory illusion is perfect when misleading cues have been eliminated and is like a magician’s trick (Loudspeakers and room disappear from the auditory scene) Hearing & Stereo - 2 5) The room reflected and reverberated sound must have the same timbre as the direct sound from the speakers to eliminate misleading cues (Constant Directivity loudspeakers) 6) Room reflections must be delayed for segregation from the direct sound streams (>6 ms)" (http://www.linkwitzlab.com/AES-Helsinki'13/Stereo_loudspeakers-room-2.pdf)

I’ve been a big fan and an avid reader of Linkwitz for decades. What a contribution, and like Pass, so generous to the DIY community. Respect.

However, I eventually came to the conclusion that his contribution lies more in the conceptual than in the validational. (New word )

He wrote an awful lot about human perception and perceptual cues and the advantages of dipoles and (later on, with some partial backtracking of his early thoughts, presumably after hearing his Pluto experiments) omnidirectionals. And the manner in which he laid out his thoughts on this topic is highly impressive and influential to the lay reader, e.g. me. But, his commentary that forms his own thoughts on this matter, and not just recitation of valid experimental findings, needs validation.

And I’m not aware of that validation ever happening through well-constructed independent listening experiments. Would be very grateful if anyone can point to such validation.

If not, then a big asterisk lies over his conclusions. I got the impression that Linkwitz validated and evolved his views via casual, sighted, personal home listening tests. With a lot of ’feed-forward’ effect, leading to further writings and conclusions and speaker design work on that basis. That’s not really acceptable to me. I hope you realise that is not meant as disrespect. Just standard validation expectations.

Whereas Toole, conversely, exclusively develops his understanding from valid experimental findings. The views that he puts forth have been tested. So, when Linkwitz expressed disagreement with Toole, I reluctantly lean away from Linkwitz. An example being when he wrote, “Much has been investigated and is presented by Floyd Toole in Sound Reproduction - Loudspeakers and Rooms. Far from "being fundamentally flawed" I have found that a 2-channel stereo system is capable of greater spatial realism and believability than n-channel systems typically achieve. Rather than overpowering the brain into surrender to direct sound streams from n-directions for forming a spatial impression, a 2-channel playback cooperates with evolutionary hearing mechanisms, provides a minimum set of spatial cues from two direct streams and from room streams of sound for rendering a frontal auditory scene, which is familiar when appropriately recorded. The perceptual apparatus fills in when cues are missing, but gets distracted when cues won't fit with the formation of a believable mental image and leads to the question: Where am I?.” Impressive reading, but, to me, it leads to the question: Is this validated? Because he is disagreeing with a view that is validated. He writes, above, “I have found...”: how?

Same for omnidirectional speakers. IIRC Linkwitz was very surprised by his, presumably uncontrolled, listening impressions of the early Pluto, and started to fold the omni into his writings on dipole radiation advantages from that point. If that is how he formed the impressions that led his writing, then I question the whole body of work on omnis. We all know how ‘DIY bias’ works: gee, I’m listening to some of it right now!

Being a rightful doyen does not exempt him from due process. So when he says “I have found”... how?

cheers

 

[Blumlein 88]

For the record, I'm a long time fan of the big panel dipolar ESL. My current speakers are Soundlabs with Revels in my video rig.

 

[thewas]

Yes, but imo the way you'd "voice" an omni is with the same gently downward-sloping response at all horizontal angles, including of course "on axis".

My personal perception in my current small and acoustically too live room which of course is just one sample and doesn't mean enough for a generalisation is that when I try to do that with very wide directivity loudspeakers (I don't have omnis) they just sound lacking detail as I perceive more the direct sound tonality above room transition frequency, while when letting the direct sound flat there is too much energy which is tiring me, plus the imaging is less pinpoint than on higher directivity loudspeakers.

I think that directivity preferences strongly depend on the room, listening distance, listening material and personal preferences, so I don't think that there will ever be a common consensus on it, I would advice finalised records music listeners like most of us here to test both and chose what they like more depending on above, as like it has been correctly said, stereo is a underdimensioned illusion where only the listener can decide how it works best for him.

 

[whazzup]

We intend to find out the answer to that question this year.

Cool, would love to hear more when you do.

 

[aarons915]

That's an interesting idea.

On one hand, I have found that for most speakers I've owned the more room reflections the more "live" the sound, but the more hashy it becomes.
Subjectively a sort of scrim of whitening hash seems to accompany everything. This could of course me the particular sound of my room under certain conditions. (However, as I've said, I have good flexibility in my room in terms of making it sound more live or more dead).

On the other hand, one of the distinctive characteristics I found with my MBLs, subjectively, was a "super low noise floor" sensation. They sounded very free of hash, and the low level sonic information, e.g. even just the finger padding of someone playing a classical guitar lightly, seemed more easily heard and more natural than I have heard anywhere else. That's part of what sounded so convincing with my MBLs, it didn't *sound* hyped where upper frequency transients have exaggerated clarity. Rather it was more like someone just playing a guitar in front of me and I could simply choose to listen down in to as much subtle detail as I cared to.

Dang, I'm starting to miss my MBLs now!

I think a speaker with lots of reflections that sounds "hashy" is just due to that off-axis response not matching the direct sound well enough. This is why I believe with my KEF example that they sounded more clear than the Revels, which measure better. Even if the KEFs response isn't quite as neutral, I believe that since the reflections are very similar in all directions, they sound clear and more natural than typical line-source speakers. I rarely hear other people mention similar feelings about coaxials though so who knows, I don't believe I have golden ears or anything.

 

[BenB]

Yes!! That would be a "You Are There" presentation, which imo is PRIMARILY conveyed by the reflections which arrive AFTER a suitable time interval. Linkwitz aims for 6 milliseconds, Geddes for 10 milliseconds, imo these are variations on the same theme. The key is to minimize the reflections (in particular the lateral reflections) arriving before 6 milliseconds, or 10 milliseconds, as the case may be.

Putting this in perspective using the 6 millisecond threshold, if someone sits 10 feet back from speakers that are separated by 10 feet, then they will need to have the speakers 5 feet from the sidewalls, and 3.5 feet out from the wall behind them. This implies a room that's at least 20 feet wide and presumably 17 feet deep (assuming the listener needs to be 3.5 away from the back wall). I don't think we'd want all the reflections arriving together at the listening position, so the room would have to be a few feet bigger than that to allow for diversity in arrival time. Based on prior research and personal experience, I have estimated that most people would probably prefer any sidewall reflection from closer than 3 feet be treated, and that any sidewall reflection from 5 feet or more away should be maintained.
In my own personal theater, I have an asymmetric configuration (screen wall has a door on the left side). The distance from the left speaker to the left wall is about 7 feet, and is completely untreated. The distance from the right speaker to the right wall is about 2 feet, and I use a bookshelf to block (and diffuse) the reflection. I also have treatment on the right wall for the contralateral reflection from the left speaker, which I found to be quite annoying. My speakers have fairly broad and consistent horizontal dispersion.

 

[More Dynamics Please]

The wisdom of great audio minds such as Toole and Linkwitz accrues over decades. Selective historical quotes may not be representative of the sum of their peak wisdom, especially when accompanied by personal interpretations.

 

[Jukebox]

Is the music you listen to produced on such speakers? No.

This is the exact answer I received from Paul Barton of PSB; nevertheless, omni speakers brings a different approach and their sound can be on some recordings fascinating

 

[oivavoi]

I’ve been a big fan and an avid reader of Linkwitz for decades. What a contribution, and like Pass, so generous to the DIY community. Respect.

However, I eventually came to the conclusion that his contribution lies more in the conceptual than in the validational. (New word )

He wrote an awful lot about human perception and perceptual cues and the advantages of dipoles and (later on, with some partial backtracking of his early thoughts, presumably after hearing his Pluto experiments) omnidirectionals. And the manner in which he laid out his thoughts on this topic is highly impressive and influential to the lay reader, e.g. me. But, his commentary that forms his own thoughts on this matter, and not just recitation of valid experimental findings, needs validation.

And I’m not aware of that validation ever happening through well-constructed independent listening experiments. Would be very grateful if anyone can point to such validation.

If not, then a big asterisk lies over his conclusions. I got the impression that Linkwitz validated and evolved his views via casual, sighted, personal home listening tests. With a lot of ’feed-forward’ effect, leading to further writings and conclusions and speaker design work on that basis. That’s not really acceptable to me. I hope you realise that is not meant as disrespect. Just standard validation expectations.

Whereas Toole, conversely, exclusively develops his understanding from valid experimental findings. The views that he puts forth have been tested. So, when Linkwitz expressed disagreement with Toole, I reluctantly lean away from Linkwitz. An example being when he wrote, “Much has been investigated and is presented by Floyd Toole in Sound Reproduction - Loudspeakers and Rooms. Far from "being fundamentally flawed" I have found that a 2-channel stereo system is capable of greater spatial realism and believability than n-channel systems typically achieve. Rather than overpowering the brain into surrender to direct sound streams from n-directions for forming a spatial impression, a 2-channel playback cooperates with evolutionary hearing mechanisms, provides a minimum set of spatial cues from two direct streams and from room streams of sound for rendering a frontal auditory scene, which is familiar when appropriately recorded. The perceptual apparatus fills in when cues are missing, but gets distracted when cues won't fit with the formation of a believable mental image and leads to the question: Where am I?.” Impressive reading, but, to me, it leads to the question: Is this validated? Because he is disagreeing with a view that is validated. He writes, above, “I have found...”: how?

Same for omnidirectional speakers. IIRC Linkwitz was very surprised by his, presumably uncontrolled, listening impressions of the early Pluto, and started to fold the omni into his writings on dipole radiation advantages from that point. If that is how he formed the impressions that led his writing, then I question the whole body of work on omnis. We all know how ‘DIY bias’ works: gee, I’m listening to some of it right now!

Being a rightful doyen does not exempt him from due process. So when he says “I have found”... how?

cheers

I broadly agree with you on your view on Linkwitz. And I don't think he would disagree fundamentally himself: he often cast out his ideas as hypotheses, asking the audio community to investigate it further etc. The blind test conducted by Clark where the quasi-omni Imp speaker and a cheap but well-measuring Behringer monitor bested the Orions was a sobering testament to that. To his credit though, he took it seriously and it led him to refine his designs and move on from the Orions. Not bad for an older guy with lots of accomplishments under his belt who could easily have dismissed it. But I do very much agree with you that his dismissal of multichannel is based on shaky ground.

Where I do disagree somewhat is with the juxtaposition with dr. Toole as the only alternative, kind of. You didn't say that exactly (please don't take this the wrong way, I'm simplifying), but there is some tendency among people to lift up Toole's opinions as the final word. One of the merits of Toole's book is that he (mostly) presents a broad overview of the state of audio research, not just his own studies, so it's possible to assess his claims. He's often more open to diverging opinions than many of his followers, I think... (as far as I know Toole never compared stereo and multichannel himself, for example - his views here are based on the studies of others).

Concerning directivity and omnis and/or dipoles, for example, it is simply not possible to use Toole's studies to assess whether omni directivity is preferred by listeners or perceived as neutral/fidelitous. As far as I know Toole or Harman have never compared an omni speaker with conventional speakers, neither in the NRC days nor later. They did compare conventional speakers with dipole electrostats (quads and martin logan?) and found that people preferred the conventional dynamic speakers. But no comparisons with speakers such as MBL, Morrisons, Duevel, or German Physiks - or with dynamic dipoles such as the LX 521 or the LX mini. The closest one comes to this in Toole's own testing is the Mirage M1, which scored better than any other speakers in the NRC testing in Canada. [EDIT: Apparently also an Ohm Walsh speaker, which also performed well, according to the post below].
But Harman never followed up on the testing of M1, and didn't develop such speaker concepts further. My guess - which could be wrong - is that they rightly assumed that it would be hard to sell a speaker that needs to be placed well away from the front wall to function optimally.

There are a few comparative tests of these kind of speakers, but they can't be found in Toole's work. I've already linked to them in the thread - the summary can be found here: https://www.researchgate.net/public..._sound_quality_-_a_review_of_existing_studies
In Bech 1994, for example, dipoles and omnis scored badly close to the wall, but scored better than any other speakers when placed well out from the wall.

Just in order to remove any misunderstandings, I'm a big fan of Toole's work. I've read his book twice and often use it as a reference. But I don't see it as a bible. Loudspeaker research is simply too small of a research field, which warrants some humility on whether we should regard it as "settled science". As a small point of comparison, I probably have more research colleagues at the local university department where I work than there are active academic loudspeaker researchers in the whole world. So the very fact that Harman focused on the development on a certain kind of loudspeaker, does not mean that this by necessity is the ideal type of loudspeaker for reproduction of music in the home.

 

[Shazb0t]

Since we all love quoting Toole so much, here are some quotes of things he posted last year. Take from them what you will.:


In response to a question regarding "the reconstruction of the original musical event.":
"Which, of course, is quite impossible with only two channels! What we hear is only hints of what might have been, as tweaked by recording and mastering engineers. Nothing approaching the original sound field is captured, stored or reproduced. An active imagination is required, and that very likely is strongly individualistic. The problem is the "system" (stereo), not the loudspeakers. This does not mean that music cannot be extremely pleasurable, but the expanded "circle of confusion", if reality is the goal, is not a circle at all. It is a dead end, so long as we stick with two channels. Let the flames begin . . ."


Discussing his Mirage M1s:
"I have not only subjectively and objectively evaluated multidirectional designs, but I owned a pair of Mirage M1s. My comments on them as well as in-room and anechoic measurements are in Chapter 7 in my book. They are absolutely amenable to conventional evaluation. The added room reflections soften hard L & R panned images and slightly blur the panned images. This is most advantageous for large scale classical music in my opinion, but not offensive with any musical genre. I'm sure some others will disagree."

"The closest I have experienced are the Mirage M1, a bipole design that was crudely omni in the horizontal plane, and an Ohm Walsh 2 which was horizontally omni up to about 2 kHz. Both acquitted themselves very well in double-blind listening tests compared to good forward firing designs. The most obvious difference was in the spatial domain, which is to be expected, but even that was more subtle than many of us expected in direct-comparison blind tests."


Specifically discussing Omnidirectional speakers:
"The dominant sound energy and perceptions are attributable to the direct sound and the first reflections from walls, floor and ceiling (horizontal and vertical planes) - all other reflections travel much farther and encounter multiple reflecting surfaces. So, it is not necessary to have "true" omnidirectIonality, a point source, even though it is a popular theoretical, academic, concept. The question is "how close to the direct sound must the off-axis sounds be?"

"A truly omnidirectional speaker radiating a flat direct sound would exhibit flat sound power and a "flattish" room curve. There would inevitably be a small downward tilt because of air absorption, absorption at room boundaries and furnishings that tend to be a higher frequencies."

"Harman sells monitor loudspeakers to music and movie studios, and to consumers ... you will see that in order to minimize the influence of the "circle of confusion" and thereby have any hope of delivering the "art" as it was created, one needs similar loudspeakers everywhere. I know of no recording facility that uses multidirectional loudspeakers."

"They exist in homes, I believe, mainly in an attempt to improve on the spatial limitations of stereo. They are contraindicated for multichannel installations."

"However, I long ago decided that multichannel upmixing was a more rewarding way to embellish stereo. It is adjustable, and it can be turned off. A permanent form of embellishment, as in a loudspeaker design, cannot work for all recordings."

 

[MattHooper]

(My emphasis)

Since we all love quoting Toole so much, here are some quotes of things he posted last year. Take from them what you will.:


In response to a question regarding "the reconstruction of the original musical event.":
"Which, of course, is quite impossible with only two channels! What we hear is only hints of what might have been, as tweaked by recording and mastering engineers. Nothing approaching the original sound field is captured, stored or reproduced. An active imagination is required, and that very likely is strongly individualistic. The problem is the "system" (stereo), not the loudspeakers. This does not mean that music cannot be extremely pleasurable, but the expanded "circle of confusion", if reality is the goal, is not a circle at all. It is a dead end, so long as we stick with two channels. Let the flames begin . . ."

Yes, that is why I found your previous comment curious:

How can you read this thread and not understand that Omnis have no possible ability to reproduce most music as it's currently recorded with any sort of accuracy to the original performance? It's mind boggling.

It's all an illusion, and why be ragging on omnis for being impossible to actually re-create The Original Performance, when it's not really possible for any speaker?

As Floyd and others have pointed out, the way most music is mic'd, and the way microphones/stereo works, means it's not suited to "accurately reproduce the original live performance." So, depending on our goals, we pick our compromises, or solutions. I found that my omnis, while not in fact reproducing the original sound, produced qualities that *mimicked* the sensation of hearing real instruments, and so to some degree mimicked (one may even say, carefully, "restored") a sense of the original sound. And I had the original sound to actually compare.

 

[andreasmaaan]

Specifically discussing Omnidirectional speakers:
"The dominant sound energy and perceptions are attributable to the direct sound and the first reflections from walls, floor and ceiling (horizontal and vertical planes) - all other reflections travel much farther and encounter multiple reflecting surfaces. So, it is not necessary to have "true" omnidirectIonality, a point source, even though it is a popular theoretical, academic, concept. The question is "how close to the direct sound must the off-axis sounds be?"

"A truly omnidirectional speaker radiating a flat direct sound would exhibit flat sound power and a "flattish" room curve. There would inevitably be a small downward tilt because of air absorption, absorption at room boundaries and furnishings that tend to be a higher frequencies."

"Harman sells monitor loudspeakers to music and movie studios, and to consumers ... you will see that in order to minimize the influence of the "circle of confusion" and thereby have any hope of delivering the "art" as it was created, one needs similar loudspeakers everywhere. I know of no recording facility that uses multidirectional loudspeakers."

"They exist in homes, I believe, mainly in an attempt to improve on the spatial limitations of stereo. They are contraindicated for multichannel installations."

"However, I long ago decided that multichannel upmixing was a more rewarding way to embellish stereo. It is adjustable, and it can be turned off. A permanent form of embellishment, as in a loudspeaker design, cannot work for all recordings."

My interpretation of the above (and other Toole writings on loudspeaker directivity) is that he believes that omnidirectional loudspeakers are an excellent choice for two-speaker stereo reproduction (as they enhance perceived spaciousness) but a poor choice for multichannel reproduction (as the spatial cues already contained in multichannel recordings are actually diminished by too many/too strong reflections).