omnidirectional loudspeakers = best design available

[jim1274]

Or you can use curtains, bookshelves etc... as methods of mitigating some of the reflections making them much more viable... with due care!

Speaking as a long term owner of bipole/dipole speakers (electrostatics) and wide dispersion 270 degree speakers (Gallo's).... you don't necessarily have to place them out in the room (although that is the best case option)- but you DO have to take the nearby surfaces into account, and plan accordingly.

Acoustically treating areas behind and to the sides helps reduce rhe total amount of reflective energy, but does it help with the timing? It seems the timing of early reflections is important from what I’ve read. The closer to reflective surfaces, the shorter the timing of the early reflections.

I understand room physical limitations often preclude moving speakers well out into the room, but well worth a try for a short session and see how that impacts the sound.

 

[MattHooper]

Acoustically treating areas behind and to the sides helps reduce rhe total amount of reflective energy, but does it help with the timing? It seems the timing of early reflections is important from what I’ve read. The closer to reflective surfaces, the shorter the timing of the early reflections.

I understand room physical limitations often preclude moving speakers well out into the room, but well worth a try for a short session and see how that impacts the sound.

MBL says about their omnis that they are not fussy in that regard and in fact, the idea is that they actually work well in “normal rooms” because reflectivity is part of the Omni effect.

When I had my MBLs I had them pulled out about 4 feet into my room. I tried more reflectivity and less reflectivity and I found I could generally enjoy them either way. The reflectivity making for a more lively vivid sound, cutting down reflectivity made for more subtle tonal nuance.

 

[MarkS]

"reflectivity is part of the Omni effect"

Yes exactly. I don't really see what the point would be of getting omni speakers and then trying to tame the reflections ...

 

[jim1274]

"reflectivity is part of the Omni effect"

Yes exactly. I don't really see what the point would be of getting omni speakers and then trying to tame the reflections ...

Exactly, but if they were too close to reflective surfaces generating reflections too early, maybe reducing magnitude might have some merit?

If you can’t give Omnis enough “breathing room”, maybe better to just use unipoles.

Omnis benefit greatly from dialing-in the best location in a given room. In my room, that ended up being a large distance from the walls, almost nearfield.

 

[FitmanNJ]

Before his passing a couple of years ago, I spoke by phone directly to John Strohbeen, the "Father" of Ohm Acoustics. I was calling "Customer Service" to ask about recommended room treatment for my Ohm Walsh 2000 speakers. Surprisingly, in those days, John often used to answer the phone himself. He didn't address how far to place the speakers from the front wall, although I seem to recall reading an article on Ohm's website that recommended something like 15"-24" (after testing, I'm currently at 17").

He did suggest a simple rule of thumb for room treatment, however. He said the best sounding Ohm speakers that he'd ever heard used reflection or diffusion in the front half of the room, and absorption in the back half of the room. At that point, I had been approaching room treatment using the most often recommended advice, e.g., absorption at first reflection points, etc. The results had been mixed (hence my call for assistance).

I now have, per John's recommendation, purely reflective front and side walls, and recently completed installation of some large homemade bass traps on the walls behind and to the sides of my listening position (~12" in depth including two layers of absorptive material, mounted with a 6" air gap). My REW measurements, although not perfect in my acoustically limited room, have noticeably improved, particularly in the bass region.

The final step was placement of about 5" of some inexpensive acoustic foam directly behind the listening position to address the unfortunate fact that due to practical room considerations, I'm forced to sit very close to the rear wall. This tightened up the soundstage imaging and eliminated a rare but occasional high frequency harshness. I'm no "big hitter" in the audiophile game, but I'm absolutely delighted now with the sound I get from my comparatively modest Ohm Walsh system.

 

[MattHooper]

He did suggest a simple rule of thumb for room treatment, however. He said the best sounding Ohm speakers that he'd ever heard used reflection or diffusion in the front half of the room, and absorption in the back half of the room.

In my case, I had the opposite: much more absorption in the front half of the room and almost none on the opposite side of the room by the sofa. Perhaps it would’ve worked even better if I’d had the reverse, but I got fantastic sound from the MBLs in my room.

My MBL omnis (this is a photo when I was selling them… I can’t find photos at the moment with them set up in my listening room - those used to be on another image hosting site that I don’t use anymore)

FWIW, here’s the room I placed at the MBL’s in.

This is from behind my current speakers looking towards the listening seat. The listening sofa is pulled forward of the bay window area behind the sofa. So there’s a good distance from my head to the back wall or window windows behind me..
You can see thick brown belted curtains on one side of the wall that I could spread out or gather at any point, depending on where I wanted to kill higher frequency reflections and how much:

The MBLs were pulled well out from the back wall towards the listening position, similar to what you see with these speakers.
An acoustician was employed for my room renovation - the ceiling bulkhead is a metal frame with stretched. Dark brown felt fabric behind which acoustic treatment is strategically placed. And you can see that the other side of the room behind the speakers is where my home theatre screen is and my home theatre speakers. That side of the room is much more absorptive. It’s covered with various layers of velvet, including hanging panels of black velvet that act as adjustable screen size masking. And then around the screen, and in the corners are hidden more acoustic treatment:

I also have a brown velvet cover that fits over the fireplace for listening to kill the reflectivity of those tiles. And I can pull the large thick velvet curtains wherever I want along the wall as well.

So when I had my MBLs I would experiment with greater or lesser reflectivity in the room by covering more or less of the wall reflections, and also I could vary the level of reflectivity to a degree on the screen wall behind the speakers, because the screen was surrounded by automated four way black velvet masking panels. So I could make the screen entirely disappear and so that wall became very non-reflective, especially in higher frequencies. Or I could open up the size of the more reflective projection screen area to add more reflectivity on that side of the room.

As I mentioned, I enjoyed both a very reflective presentation and a less reflective presentation. But the best I achieved was in carefully dialling in all these elements to get just the right mix of reflection and absorption, and then real magic happened!

 

[dlaloum]

Acoustically treating areas behind and to the sides helps reduce rhe total amount of reflective energy, but does it help with the timing? It seems the timing of early reflections is important from what I’ve read. The closer to reflective surfaces, the shorter the timing of the early reflections.

I understand room physical limitations often preclude moving speakers well out into the room, but well worth a try for a short session and see how that impacts the sound.

a bookshelf full of various different size books and such, will result in very diffuse reflected sound as it breaks it up into various different directions, rather than a mirror-like direct reflection (and books also absorb a range of frequencies) - the sound that is redirected further to the sides, then bounces off side walls (and whatever treatment has been placed there) - hence taking longer to reach the ear. (also the old "eggcarton" wall treatment, the point of which is to stop the direct reflection, and break it up towards the sides where it then has to bounce off one or more other surfaces, both delaying it and potentially reducing its level)

So yes - there are ways and means - and achieving the required 20ms delay between main and reflection can be done via means other than simple distance from the rear wall...

 

[dlaloum]

"reflectivity is part of the Omni effect"

Yes exactly. I don't really see what the point would be of getting omni speakers and then trying to tame the reflections ...

It may not be a matter of "taming" but a matter of delaying... so they are present in the room, but reach the ear some ms' later.... and delay can be achieved by mechanisms that cause the reflection to bounce of the rear wall towards the sides - rather than straight back at you - potentially doubling the travelled distance and therefore the delay time.

 

[EJ3]

It may not be a matter of "taming" but a matter of delaying... so they are present in the room, but reach the ear some ms' later.... and delay can be achieved by mechanisms that cause the reflection to bounce of the rear wall towards the sides - rather than straight back at you - potentially doubling the travelled distance and therefore the delay time.

I have always considered that a form of "taming":
It just happens after the sound is released into the room as opposed to inside the electronics.

 

[FitmanNJ]

In my case, I had the opposite: much more absorption in the front half of the room and almost none on the opposite side of the room by the sofa. Perhaps it would’ve worked even better if I’d had the reverse, but I got fantastic sound from the MBLs in my room.

My MBL omnis (this is a photo when I was selling them… I can’t find photos at the moment with them set up in my listening room - those used to be on another image hosting site that I don’t use anymore)

View attachment 513992

FWIW, here’s the room I placed at the MBL’s in.

This is from behind my current speakers looking towards the listening seat. The listening sofa is pulled forward of the bay window area behind the sofa. So there’s a good distance from my head to the back wall or window windows behind me..
You can see thick brown belted curtains on one side of the wall that I could spread out or gather at any point, depending on where I wanted to kill higher frequency reflections and how much:

View attachment 513986

The MBLs were pulled well out from the back wall towards the listening position, similar to what you see with these speakers.
An acoustician was employed for my room renovation - the ceiling bulkhead is a metal frame with stretched. Dark brown felt fabric behind which acoustic treatment is strategically placed. And you can see that the other side of the room behind the speakers is where my home theatre screen is and my home theatre speakers. That side of the room is much more absorptive. It’s covered with various layers of velvet, including hanging panels of black velvet that act as adjustable screen size masking. And then around the screen, and in the corners are hidden more acoustic treatment:

View attachment 513989

View attachment 513990

I also have a brown velvet cover that fits over the fireplace for listening to kill the reflectivity of those tiles. And I can pull the large thick velvet curtains wherever I want along the wall as well.

So when I had my MBLs I would experiment with greater or lesser reflectivity in the room by covering more or less of the wall reflections, and also I could vary the level of reflectivity to a degree on the screen wall behind the speakers, because the screen was surrounded by automated four way black velvet masking panels. So I could make the screen entirely disappear and so that wall became very non-reflective, especially in higher frequencies. Or I could open up the size of the more reflective projection screen area to add more reflectivity on that side of the room.

As I mentioned, I enjoyed both a very reflective presentation and a less reflective presentation. But the best I achieved was in carefully dialling in all these elements to get just the right mix of reflection and absorption, and then real magic happened!

In their "Walsh ####" line of speakers, Ohm Acoustics puts some absorptive material in behind/toward the front wall of the downfacing main driver, reducing rear-directed sound. I think this is designed to make them more forgiving with regard to reflections off the recommended untreated/reflective front wall (not sure why they just don't recommend front wall absorption...maybe it's "too much of a good thing?"). So, they are not fully omni-directional speakers (maybe 280 degrees horizontally?).

As long as you're sharing photos, here's my setup. Mind you, I'm single, so this is absolutely a man-cave at this point and admittedly suffers in aesthetics -- sound quality is the priority! As you can see, I've used dense particle board to create reflection points where they don't exist in the room itself: behind to fill the stairway opening, and left/right to create equidistant reflection points at the main listening position. It's a hack, I know, but the panels have proven to deliver an improvement in sound quality (although probably not as much as if there were actual walls there). I have a second subwoofer hidden behind the couch. And, yes, as I'm a personal fitness professional, that is indeed a treadmill and stationary bike ergometer in the room -- I have nowhere else to put them! It's remarkable that it sounds as good as it does.

 

[MattHooper]

In their "Walsh ####" line of speakers, Ohm Acoustics puts some absorptive material in behind/toward the front wall of the downfacing main driver, reducing rear-directed sound. I think this is designed to make them more forgiving with regard to reflections off the recommended untreated/reflective front wall (not sure why they just don't recommend front wall absorption...maybe it's "too much of a good thing?"). So, they are not fully omni-directional speakers (maybe 280 degrees horizontally?).

As long as you're sharing photos, here's my setup. Mind you, I'm single, so this is absolutely a man-cave at this point and admittedly suffers in aesthetics -- sound quality is the priority! As you can see, I've used dense particle board to create reflection points where they don't exist in the room itself: behind to fill the stairway opening, and left/right to create equidistant reflection points at the main listening position. It's a hack, I know, but the panels have proven to deliver an improvement in sound quality (although probably not as much as if there were actual walls there). I have a second subwoofer hidden behind the couch. And, yes, as I'm a personal fitness professional, that is indeed a treadmill and stationary bike ergometer in the room -- I have nowhere else to put them! It's remarkable that it sounds as good as it does.

View attachment 514187View attachment 514188View attachment 514189View attachment 514190View attachment 514191

There’s some heroic moves going on there to satisfy sound quality


What’s going on with the wall behind the listening sofa? What is that structure? Did you make it and is it for acoustics? Are the rectangular pillars to the side bass traps?

 

[FitmanNJ]

There’s some heroic moves going on there to satisfy sound quality


What’s going on with the wall behind the listening sofa? What is that structure? Did you make it and is it for acoustics? Are the rectangular pillars to the side bass traps?

The things you see behind the sofa are all bass traps of one form or another. Most of them began as GIK 7.5" thick "Monster Traps" that I had purchased before this latest building project. After viewing some YouTube videos from Vespers ("Warp Academy") and considering a new product now being offered by Music City Acoustics (the "SubFreQ"), I thought I could modify what I had to create a homemade version of the SubFreq, which MCA is touting as particularly effective for bass trapping due to it's depth and "dual-density insulation."

First, I replaced the Rockwool in the Monster Traps with a similar, but lighter weight material per Vespers' advice and the SubFreq design. Then, I added an additional ~5.5" of wooden frame and filled it with R19 fiberglass. You can see the additional depth in the rear portion of each trap. Finally, I either corner mounted these traps on a wall-ceiling or wall-wall interface, or used 6" wooden "legs" to space them off the wall for additional bass absorption versus a flat wall mount. The large traps that I think you've referred to as the "rectangular pillars to the side" are the only outliers in that I made them to the same dual-density design, but entirely from scratch. They provide the best view of the 6" air gaps I created.

I didn't deepen the two traps immediately behind the listening position to provide additional space behind my ears with the hope of limiting high-frequency reflections, making them look recessed. I placed the black acoustic foam in that area with the same goal in mind.

I saved quite a bit of money going DYI. It wasn't an easy project as I'm no carpenter, but I was able to get the job done without cutting off any fingers!

GIK Monster Trap modification (sorry...I can't seem to do anything to stop the photos from rotating):


Trap made from scratch:

 

[Newman]

It has been interesting to follow the trajectory of this thread.

As hinted in the title, it started with a bold proclamation of the clear and indisputable superiority of the omnidirectional speaker principle for sound reproduction.

• They produce the most realistic soundstage
• Their superiority is easily audible
• …and easily seen in the measurements
• They are naturally aligned with our ear-brain mechanism
• All other loudspeakers are designed incorrectly
• …and easily verifiable with measurements
• All other loudspeakers are totally unnatural
• Anyone who is serious about music should adopt them
• The 2 best omni speakers are automatically the 2 best loudspeakers in the world
• So far superior to a standard speaker, it is not even close (post 3)
• All forward firing speakers are inherently flawed and totally outdated (post 138)
• If you want to progress you have no option but to go omni

Slowly but surely, a science-based discussion emerged in which every important aspect of the opening declaration was debunked. Inherent superiority became inherent inferiority.

It was not plain sailing from A to B, though, because, just like any audio thread to discuss an unusual technology, it attracts current owners, past owners, and excited fan type observers, who tend to search the internet for any and all discussion of their favourite toy. Not just on Day 1 of the thread, but newcomers find it again and again, for years. Understandably, they are reluctant to concede that the ‘obvious’ advantages may be disadvantages when put to the Bunsen burner. But I think the thread got there in the end.

And the most recent revival of the thread has settled into a general chat line for omni speaker talk, unrelated to the topic title. All good.

But since the current discussion is about whether to ‘manage’ the way-off-axis output (and hence reflections), or to ‘free’ them, I reckon it’s worth a quick reminder of where the science-based discussion landed.

Firstly, in diametrical opposition to the claims of proponents, the dispersion of an omni is completely unlike the dominant musical instruments or the human voice. Conventional speakers are a much closer approximation.

Secondly, psychoacoustic research into preferred vs non-preferred room reflections has shown that the reflected content that the listener experiences from an omni, is of the wrong amplitude, wrong timing, and from the wrong directions. And all of those wrongs can be righted by using a conventional multichannel setup.

I think the above landing points are worth reiterating, because I am pretty sure that most people who went to omni speakers did so on the understanding that they were pursuing ultimate sound reproduction, ie they have very high standards for desired sound quality and are keen enough to pursue it, and omni was being touted as the ultimate way to approach it. To those people, learning that the core principles of omni speakers are quite problematic, inherently so, and pursuing them can do little other than lead them away from ultimate sound reproduction, should be an enlightenment that they welcome. And worth reiterating from time to time.


cheers

 

[Flaesh]

I don't really see what the point would be of getting omni speakers and then trying to tame the reflections ...

Ha. One can\may take the omnis outside and find or not find the benefit if the listener's position changes.

 

[BenB]

...
Secondly, psychoacoustic research into preferred vs non-preferred room reflections has shown that the reflected content that the listener experiences from an omni, is of the wrong amplitude, wrong timing, and from the wrong directions. And all of those wrongs can be righted by using a conventional multichannel setup.

I think the above landing points are worth reiterating, because I am pretty sure that most people who went to omni speakers did so on the understanding that they were pursuing ultimate sound reproduction, ie they have very high standards for desired sound quality and are keen enough to pursue it, and omni was being touted as the ultimate way to approach it. To those people, learning that the core principles of omni speakers are quite problematic, inherently so, and pursuing them can do little other than lead them away from ultimate sound reproduction, should be an enlightenment that they welcome. And worth reiterating from time to time.


cheers

None of the studies on preferred vs non-preferred room reflections have been done correctly, rendering them almost completely useless for guiding us toward improved audio reproduction. If you want to know whether a reflection is preferred for home audio, you have to show that there aren't alternative methods of changing the sound that are more preferred. For example, a reflection increases the perceived volume and induces a shift in the spectral balance (a warming effect) when compared to the reflection-free reproduction. If listeners prefer the reflection to the reflection-free case, you haven't demonstrated that they actually like the reflection itself; listeners may be more satisfied with a reflection-free playback that is matched in loudness and spectral balance (in a broadband sense) to playback with the reflection.

Additionally, the studies often assess reflection preference in isolation. Just because we prefer a reflection from a particular angle to no reflection at all (which is a very unnatural situation for us) doesn't mean that we prefer that same reflection when we are overwhelmed by reflections from various angles and delays. I'm sure I'll prefer a cake baked with sugar or honey or syrup to one with no sweetener, but that doesn't mean my cake needs to have sugar and honey and syrup.

 

[EJ3]

Ha. One can\may take the omnis outside and find or not find the benefit if the listener's position changes.

We don't have any omnis but at my mother's I do take the speakers onto the rear deck, and use the rear brick wall of the house to reflect the sound that gets behind the speakers toward the back yard. When she has people over to grill out, music can be heard well enough when we are grilling food and shrimping, crabbing and fishing from the end of her dock (about 130 feet away). It helps the ambiance. I suppose that because there are no side wall or ceiling reflections and all the floor bounce from the concrete patio deck (which is about 30" above ground level and the overhead cloth awning) are projected away from the house, this might have turned the speakers into some sort of 1/2-3/4 omni effect?

 

[MattHooper]

It has been interesting to follow the trajectory of this thread.

As hinted in the title, it started with a bold proclamation of the clear and indisputable superiority of the omnidirectional speaker principle for sound reproduction.

• They produce the most realistic soundstage
• Their superiority is easily audible
• …and easily seen in the measurements
• They are naturally aligned with our ear-brain mechanism
• All other loudspeakers are designed incorrectly
• …and easily verifiable with measurements
• All other loudspeakers are totally unnatural
• Anyone who is serious about music should adopt them
• The 2 best omni speakers are automatically the 2 best loudspeakers in the world
• So far superior to a standard speaker, it is not even close (post 3)
• All forward firing speakers are inherently flawed and totally outdated (post 138)
• If you want to progress you have no option but to go omni

Correct.

The thread started with some bold proclamations by a single member, and virtually everything else that followed settled in to more sober and reasonable analysis, including from others who had tried or owned omnis, who raised reasonable caveats and who weren’t making outrageous claims.

It was not plain sailing from A to B, though, because, just like any audio thread to discuss an unusual technology, it attracts current owners, past owners, and excited fan type observers, who tend to search the internet for any and all discussion of their favourite toy.

It’s been pointed out many times that this type of condescending, belittling tone doesn’t help your message Newman.

Understandably, they are reluctant to concede that the ‘obvious’ advantages may be disadvantages when put to the Bunsen burner.

No, the advantages remain advantageous.
In real life most of us are dealing with compromises. Stereo set ups have compromises. Surround set ups introduced compromises. We’re not just dealing with the theoretical “ best possible surround systems versus best possible stereo omni” set ups.
And people have different tastes and goals in which the advantages of Omnis can play a part. And the added spatial presentation of Omnis over standard direct-radiating speakers CAN be that advantage.

Since you refuse to consider my experience owing omnis as well as a high quality surround system, perhaps you will be more willing to listen to Floyd Toole on this.

Floyd has expressed satisfaction with a pair of omnis he once owned - pointing out also that they did well in blind tests:

“- I purchased a pair of nearly omnidirectional Mirage M1s for my large, somewhat live, classical "concert hall" - the largest I could afford at the time . They did well in small room double-blind tests at the NRCC, and in this situation they were to simulate an orchestra: wide dispersion, lots of reflections, etc. combined with neutral timbre and very uniform dispersion (anechoic and in room measurements are shown). They worked well and did not draw attention to themselves. (I also had a home theater).”

So Floyd is describing clear advantages in the Omni presentation for pleasurably simulating some aspects of live orchestral sound. Your writing about how “wrong” Omnis are in so many ways is clearly missing some important analysis in terms of what they can do “right” when it comes to their real world presentation and listener perception, given the appropriate goals.

Floyd was ASKED HERE if he would now have preferred to replace those Omni’s with a multi channel system in that same room.

Floyd’s reply:

“Good question. It was a large, very diffuse room, and for some programs it was just unique and quite wonderful. If I still had that house I would likely have upgraded to more powerful dipole/omnis. I had a multichannel system in my home theater, this was our living/dining room and didn't deserve to be visually corrupted to audio gear. Even I have limits.”

So we have Floyd who is aware of any arsenal you want to bring against Omnis vs direct radiating speakers….pointing out the Omnis produced some unique and wonderful characteristics. And that stereo speakers were more suitable for his application than multi channel in that room. Yet when it comes to stereo loudspeakers Floyd STILL seems to favour going with omnis (or dipoles) over conventional direct radiating speakers for that room!

Floyd wasn’t of course claiming that the omnis outperformed a suitably high-performance surround system. But in a decision about a stereo set up they could have their advantages, and even produce some unique qualities. This is exactly what I have said as well. My omnis could not replicate the full immersion of my high-quality surround set up. But the presentation is still DIFFERENT from the surround sound and can produce some UNIQUE qualities on some program material.


So, again…yes Omnis can have real advantages over conventional speakers, depending on the use-case, preferences and goals of the audiophile. And yes that can include, in certain cases, a more “natural/believable” presentation in some aspects.

You do a disservice to imply otherwise.

I am pretty sure that most people who went to omni speakers did so on the understanding that they were pursuing ultimate sound reproduction, ie they have very high standards for desired sound quality and are keen enough to pursue it, and omni was being touted as the ultimate way to approach it.

I’d bet that most who ended up with Omnis were drawn to them through listening encounters, not mere theory.

In my case my first encounter with omnis were the MBLs at a CES show, where I found myself mesmerized by what in my perception was the most realistic sound at the show. I’ve never heard an Omni before. Never even considered them. And it was further encounters with those speakers that only strengthened my impressions. As did owning them.

To those people, learning that the core principles of omni speakers are quite problematic, inherently so, and pursuing them can do little other than lead them away from ultimate sound reproduction, should be an enlightenment that they welcome.

That’s just a silly false dichotomy.
Omnis can produce some unique sonic characteristics in many scenarios, which can be a pleasure to experience. If somebody’s happy with that, they are happy. And it doesn’t mean that they also can’t enjoy surround as well. Somebody reading your characterizations could be dissuaded from a very enjoyable experience with omnis.

Omni owners generally don’t need “saving” from themselves. Many can enjoy them without the strawman absolutism you seem to imply.

I would have missed out truly wonderful listening experiences if I had been dissuaded from owning Omnis by anti-Omni advocacy like yours. I loved owning them and don’t regret having gone that route at.

Neither, it seems, does Floyd Toole regret owning omnis and he still sees them as a viable choice. So it’s possible to understand and enjoy some of the particular advantages of Omnis without being led astray as you suggest.

 

[Arindal]

No, the advantages remain advantageous.

If we are speaking about the major tradeoff between enveloping reverb/ambience vs. localization stability/precision, I would say that the advantage of achieving the former to the fullest, inevitably means a compromise on the latter aspect.

Maybe I am biased here, as I pay a lot of attention to localization (which basically every recording engineer experienced in classical recordings would, as positioning main microphones and panning spot microphones for matching localization and coherent imaging, is one of the things to do the most during mixdown). So for me personally, omnis have never been an option.

a science-based discussion emerged in which every important aspect of the opening declaration was debunked. Inherent superiority became inherent inferiority.

Have to partly disagree with that even from the perspective of inherent shortcomings of omnis. Particularly the parts on realistic soundstage (I would rather say realistic reverb field, not including the direct sound), measurements, alignment with the brain mechanism of perceiving ambience, flawed behavior of most direct-radiating speakers, are not ´debunked´ by any means. We have to have a long discussion on ideal reproduction, actual recordings and personal listening taste, to work out clear disadvantageous of omnis and to which extent their supporters are willing to accept them.

Firstly, in diametrical opposition to the claims of proponents, the dispersion of an omni is completely unlike the dominant musical instruments or the human voice. Conventional speakers are a much closer approximation.

That is not true, as there as a lot of natural instruments approximating omnidirectional radiation pattern, and pretty much none which are close to a conventional speaker with increasing directivity index. And even if that would be true, it would be a pointless argument. Speakers are not meant to reproduce a directivity pattern of a specific instrument, like a trumpet, always producing the characteristic reverb pattern of a trumpet, as that would mean they are incapable of reproducing any other instrument. You don´t want to hear a human voice or a violin or a clarinet with the directivity pattern and reverb of a trumpet, do you?

Directivity pattern of natural instruments are in case of acoustic recordings, part of the recording itself, as the reverb tonality and reflectrogram in the concert venue is a result of these. We don´t need to apply a second layer of characteristic reverb, we just have to make sure the reverb in the listening room does not dominate or tonally kink the reverb on the recording.

A perfectly constant directivity index, as delivered by omnis (and other concepts), is in theory a good starting point for such subtle reverb field. Much much better than any speaker with non-constant directivity index.

psychoacoustic research into preferred vs non-preferred room reflections has shown that the reflected content that the listener experiences from an omni, is of the wrong amplitude, wrong timing, and from the wrong directions.

Could you please link or summarize such findings? It sounds illogical to me, particularly when taking the tonality part of reverb into account. I would say the ´wrong amplitude, wrong timing, wrong directions´ are rather applicable to typical non-constant directivity speakers. The main problem of omnis I see is rather a dominant indirect soundfield, but not a kinked one.

Seeing the broader picture of the story is kind of an irony: Both Dr. Toole and Amir have been stated that linear frequency response is the most important aspect of loudspeaker quality, furthermore explaining that broad radiation pattern leading to more side wall reflections, broader imaging width, reduced proximity (and deteriorated localization stability) was statistically preferred in their controlled tests.

If you take this all at face value, well, omnis must be the ideal speakers according to ´the science´. My personal objection that localization stability, precision and retained depth-of-field/proximity are important aspects of sound quality (on which omnis in my understand cannot deliver), were dismissed as irrelevant, solely subjective, or inherent to the recording, not the loudspeaker. Well, here we are...

 

[gnarly]

Well, lord knows we all have different tastes in music....and I guess my reason for liking omnis is a bit off the beaten path.
I like them because imo they mask "hi-fi" reverb that aims for envelopment, blurring it to the point where it doesn't bug me. I really dislike reverb.
It's never convincing enough to make me think "I'm there". So I don't want to be there.....

 

[Newman]

[to Arindal]

....That is not true, as there as a lot of natural instruments approximating omnidirectional radiation pattern, and pretty much none which are close to a conventional speaker with increasing directivity index.

Yeah.....you really haven't read Toole's books, have you?

And even if that would be true, it would be a pointless argument. Speakers are not meant to reproduce a directivity pattern of a specific instrument, like a trumpet, always producing the characteristic reverb pattern of a trumpet, as that would mean they are incapable of reproducing any other instrument. You don´t want to hear a human voice or a violin or a clarinet with the directivity pattern and reverb of a trumpet, do you?

Again....try harder to be fact-based.

Noted, however, that you support my conclusion that the OP's claim of the critical superiority of the 'natural' dispersion of omnis, is debunked, but you have your own reason for landing there.

Directivity pattern of natural instruments are in case of acoustic recordings, part of the recording itself, as the reverb tonality and reflectrogram in the concert venue is a result of these. We don´t need to apply a second layer of characteristic reverb, we just have to make sure the reverb in the listening room does not dominate or tonally kink the reverb on the recording.

A perfectly constant directivity index, as delivered by omnis (and other concepts), is in theory a good starting point for such subtle reverb field. Much much better than any speaker with non-constant directivity index.

What theory?

Could you please link or summarize such findings? [preferred reflections]

Buy. And. Read. Toole.

It sounds illogical to me, particularly when taking the tonality part of reverb into account. I would say the ´wrong amplitude, wrong timing, wrong directions´ are rather applicable to typical non-constant directivity speakers.

Yeah...this is what's happening here, isn't it? You have a gut-based feeling, boosted with internal logic, and no data.

The main problem of omnis I see is rather a dominant indirect soundfield, but not a kinked one.

Seeing the broader picture of the story is kind of an irony: Both Dr. Toole and Amir have been stated that linear frequency response is the most important aspect of loudspeaker quality, furthermore explaining that broad radiation pattern leading to more side wall reflections, broader imaging width, reduced proximity (and deteriorated localization stability) was statistically preferred in their controlled tests.

If you take this all at face value, well, omnis must be the ideal speakers according to ´the science´. My personal objection that localization stability, precision and retained depth-of-field/proximity are important aspects of sound quality (on which omnis in my understand cannot deliver), were dismissed as irrelevant, solely subjective, or inherent to the recording, not the loudspeaker. Well, here we are...

"Here we are", indeed. Your landing place is what happens when internal self-logic is the guiding force, and not data.

cheers