Omnidirectional loudspeakers ?

[Floyd Toole]

Brilliant! You must have had some mighty sturdy cabinets there ...

They were custom built by a talented cabinetmaker and had two subwoofers buried inside, so no vibrations were allowed. The inverted Revel Salon2s required steel supports.

I have long felt that elevated loudspeakers were advantageous, and it is not just the tweeter - high treble - that matters. If the tweeter is at ear level, the majority of the interesting vocal and instrumental sounds originate closer to the floor - hardly a credible location if realism is the goal.

Time for some lateral (vertical?) thinking?

 

[MarkS]

If the tweeter is at ear level, the majority of the interesting vocal and instrumental sounds originate closer to the floor - hardly a credible location if realism is the goal.

I would argue that this is solved by two-way bookshelves on stands crossed to subs, at least for those of us who have moderately sized rooms and do not need loudness above orchestral mid-hall.

 

[jhaider]

Not long ago I was being toured around a loudspeaker factory and my guide, the owner, showed me examples of real and fake finishes - to me they were visually indistinguishable - making the point how peculiar it is that people are willing to pay more for the real thing, when it has nothing to do with the sound.

But...obviously the finish has nothing to do with the sound. (Well, I guess if the "finish" were thick felt...) However, the finish should align with expectations of a loudspeaker at a certain price class, which here is five figures after taxes. Also, finish type and quality goes to subjective human preference, and could be the qualifying or disqualifying factor in a loudspeaker purchase. That goes extra the purchase of an expensive loudspeaker that needs to be exposed in a presumably reasonably financially-comfortable human's presumably reasonably well-appointed living space -- you can't put a dipole against the wall and hide it behind a curtain! So such a speaker is in practice evaluated essentially as sound-making furniture. Indeed, I recall reading somewhere about someone who largely made the choice between two excellent loudspeakers -- M2 and Salon2, if memory serves -- largely on the basis of aesthetics.

Also, there's a reasonable perception that a luxury-priced loudspeaker should the justify premium price with premium inputs. Those premium inputs can be in the form of luxury materials, SOTA proprietary IP, advanced or rare components, laborious construction or finish, etc. But here, we have, again for over ten thousand dollars after tax, basically a large vinyl-wrapped MDF monkey-coffin with ordinary drivers (a lot of them, sure, but Axiom's drive units, while fine, aren't differentiated with advanced technology in the way one can say, for example, JBL M2 drive units are) and well-optimized but fairly basic engineering (no optimized tweeter waveguide geometry, for example).

The obvious retort is, if it's too expensive people won't buy it, and it will either go away or the price will be lowered until there is demand. And while that is true, it doesn't preclude a value judgment -- especially from those who own loudspeakers in that price range, who've put some thought into these things rather than just kicked the tires.

But they offer both. Modern fakes are not like the old days.

TBH while I've not been that impressed with the veneer on the Axiom-made Bryston speakers, and I don't imagine Axiom themselves use better stuff than they provide to Bryston.

I have real veneer loudspeakers that have a high-gloss finish and frankly they look more like plastic than wood. And black piano finish is paint, and it is widely respected in high end loudspeakers - but it has a connection to grand pianos.

The Revel Gem2s in our formal living room resemble those remarks.
(And yes, the price of the pedestal stands was galling. But...they look so good on those stands! Nice furniture is expensive.)

Also, hand-applied piano gloss paint fits into the "laborious construction" referenced above. Good paint is expensive to procure and requires some time investment by skilled craftspeople to apply well. So I wouldn't put paint in the same universe as a vinyl wrap.

I have heard more than a few real wood, even solid with hand-rubbed finishes, loudspeakers that sounded anything but good, and cost five figures. It's a choice - caveat emptor.

Oh for sure. But realistically that's a pretty damn lofty price point for loudspeakers. At that price, IMO, a pair of domestic loudspeakers should both be performant and well-appointed!

PS: You mention your new "streamlined" system. Admittedly I haven't yet checked out the website to the 4th ed (sorry - book is heavily read and fantastic as expected though) and maybe what I'm looking for is already there. But if you haven't sketched it out in public yet, I think a lot of people would enjoy reading your thoughts, having "been on the mountain-top," on what compromises you made to streamline for your current environment. Not necessarily component choices, mind. More on a conceptual level.

 

[dualazmak]

Hello dear Dr. Floyd Toole (@Floyd Toole) and colleagues who are onboard on this nice and exciting thread.

During the past two or three years, I have been thinking about feasibility of havening this very naive inquiry asking for thoughts and impressions of Dr. Toole regarding the limited and specific “directivity/dispersion settings” in my listening environments; now I assume it would be allowed on this exciting thread.

My L&R highly-efficient but narrow-directivity metal horn super-tweeters FOSTEX T925A are singing (ca. 8.5 kHz - 25 Hz) together with my wide-directivity 3-cm Beryllium dome tweeter YAMAHA JA-0513 (ca. 6 kHz – 14 kHz). Each of them has DSP control in upstream digital domain, and each of them is driven by dedicated HiFi "integrated amplifier" which means I can control relative gains not only in digital domain but also in analog domain, even on-the-fly (while listening to music tracks). All the SP drivers (i.e. subwoofers, woofers, midranges, tweeters, super-tweeters) have been time-aligned by DSP in 0.1 msec - 1 msec precision (ref. here #931 for the details of the latest system setup).

After my rather intensive subjective listening evaluations, I have decided physically placing the super-tweeter beneath the main SP cabinet of YAMAHA NS-1000 (ref. #27).

Spoiler

Furthermore, I recently, in June 2024, implemented wide-3D reflective dispersion of the sound of super-tweeter in that physical alignment by using heavy-hard random-face glass material (summary ref. #929).

Spoiler

As the results of these careful tunings and listening evaluations, now I have really nice (I believe so) 3D sound stage (or should I say “3D sound imaging/perspectives”?), for example I illustrated the sound perspective of lute duets (ref. #926) and jazz piano trio (ref. #927).

Spoiler

As for the 3D sound perspectives of orchestral music on which you Dr. Toole briefly touched in above a few your interesting posts, I too prefer the feelings and perspectives of the sound as if I would be sitting on the center of S-class seats in Concertgebouw Amsterdam; I wrote about it here #502. Fortunately, my present/latest setup gives nice, my preferable, such 3D orchestral sound perspectives.

Spoiler

I wrote in #502;
At present, since I like the listening feeling as if I am sitting on the best S-class center seat in Concertgebouw Amsterdam, I do not like to have my SWs (subwoofers) just beside me at my listening position; even with the "complete and perfect" time alignment of SPs I achieved, the orchestral big drum sound should be coming from the stage direction in front of my eyes and ears!

Of course, I know well that in real Concertgebouw Amsterdam (I have been there several times), I hear the entire hall tone (including the reflections, resonances, standing waves) from all the directions surrounding me, from behind, above (ceilings), side (side walls) and floor. This is the main reasons that I insists we need suitable and preferable reverberations also in our home audio listening room which somewhat "simulates" the real hall tone, but of course never to be perfect.

In my listening environment, I have fairly nice and big open spaces/rooms behind the SPs and also behind my listening position, and these (I designed so when I built my present house) are very nice for the room acoustics I fully enjoy now. Fortunately, many of the semi-professional audio enthu friends well agree me on the nice acoustics even in my present setup.

In this regard, I use nice piano concerto music tracks (ref. #650) for tuning and subjective confirmation, especially the second example in #650 recorded in Concertgebouw Amsterdam.

Spoiler

Anna Fedrova's live concert of "Rachmaninoff Piano Concerto No.2 Op.18" at Concertgebouw Amsterdam, September 2013.

The excellent recording at Leipzig Gewandhaus, I attended there several times, also serves as my reference orchestra sound (ref. #588).

Spoiler

Schubert: "Rosamunde", Kurt Masur and Leipzig Gewandhaus Orchestra (412 432-2 Philips);

Furthermore, I wrote here;
>Our ears are located left and right of our head, and hence we are rather sensitive for left-right sound image/allocation. On the other hand, our ears and brain would be relatively gullible with up-and-down sound staging, I assume. I think that my unique physical alignment (positioning) of super-tweeters at under the main SPs, together with the upper tweeters, would give pseud-coaxial sound staging if complete time alignment has been achieved like in my setup (please refer to my summary post here and here), where tweeter and super-tweeter sing together higher than about 8 kHz.

>In any way, I would like to suggest those who using super-tweeters at least trying/testing the positioning so that super-tweeter and tweeter (both in wide 3D dispersion configuration) would sandwich the woofer and squawker (midrange) from up and down.

I would highly appreciate having Dr. Toole’s (and other people’s) thoughts and comments in brief on all the above.

 

[MattHooper]

As for Revel's choice of tweeter height, I wasn't asked for an opinion. Frankly with the on-axis and listening window curves as close as they are one would need to be quite far off axis before it would make an audible difference. I had a pair of Revel Salon 2s in my home theater in California, and you can see how I treated them in this photo - the tweeters were exactly at ear level , and there was no problem with a floor bounce. A drop down screen filled the space between for movies. Actually the motivation was to keep the right channel loudspeaker from being fried by the fireplace. It sounded superb with the mids elevated, and I have repeated it in my present scaled down system. I realized that I appreciated looking slightly up at the orchestra - from the expensive seats.

This is a fascinating observation and solution!

It reminds me a little of when I had sold some tall floor standing loudspeakers that I was used to listening to, and for a while substituted some smaller Thiel 2-way stand mounted speakers. Those Thiels came with very short stands which had speakers only inches above the floor, but angled up towards the listener.

I like the sound with exception of the impression of the sound stage and imaging seeming to be too low to the ground.

But one night I tried a little experiment where I closed my eyes and just started to imagine that I was listening to taller floor standing speakers. As I did this imagination exercise, I experienced the sound staging and imaging gradually lift upwards in my perception until it seemed to match the height I was used to from the floor standing speakers. It was really wild.

As soon as I open my eyes as I recall that illusion vanished.

Ultimately, I have preferred taller speakers, or taller stands in which the imaging and sound staging seems to come from a more
“ natural” height and which don’t require the same feat of imagination as with those small Thiels.

I have long felt that elevated loudspeakers were advantageous, and it is not just the tweeter - high treble - that matters. If the tweeter is at ear level, the majority of the interesting vocal and instrumental sounds originate closer to the floor - hardly a credible location if realism is the goal.

Time for some lateral (vertical?) thinking?

Cool. I may have stumbled onto this myself not that long ago. I built a base for my current 36” tall floor standing speakers that raise them up about 6 inches higher. My perception was of a more natural, believable imaging height. How much of this is due in simply to the speakers looking visually taller or the actual sonic perception I guess I can’t say, but the perception of added height seems to remain when I close my eyes.

 

[MattHooper]

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.

That does sound like fun!

As you have pointed out before, surround systems, have some obvious advantages over two channel for producing a realistic sense of spaciousness and immersion.

On the other hand, surround is not achieving the spaciousness effect the same way an Omni does, and the Omni spacious effect can be very compelling as well. If you enjoy that effect you’re not going to get it from the average surround system using regular forward firing loudspeakers. (or at least I don’t know how it would be achieved.)

As I’ve mentioned before, I had my MBL Omnis in the same room with my home theatre surround system (I have a very nice 7.0 surround set up). As much as I enjoyed, listening to music and movie soundtracks in surround, the stereo Omnis also provided a very compelling experience of their own in terms of making the speakers and sometimes even the back of the room seem to melt away.

And I sometimes used the omnis as the R/L speakers in my surround system, and Gee Willy was that ever a cool effect! Personally, I found the sense of sonic realism in movie playback took another step forward - there was more of a sense of the front of the room around the image melding with the spatial qualities suggested in the soundtrack… so for instance a night scene with crickets felt more like I was hearing right into a space with real crickets. Since I do sound design for movies on TV, I also found playback of my own tracks to be really pleasurable in that set up as well.

In the end, ultimately I didn’t find a fully coherent mix between the Omnis and my centre channel so I stayed with my original surround set up and just used the Omnis for stereo listening.

 

[Floyd Toole]

But...obviously the finish has nothing to do with the sound. (Well, I guess if the "finish" were thick felt...) However, the finish should align with expectations of a loudspeaker at a certain price class, which here is five figures after taxes. Also, finish type and quality goes to subjective human preference, and could be the qualifying or disqualifying factor in a loudspeaker purchase. That goes extra the purchase of an expensive loudspeaker that needs to be exposed in a presumably reasonably financially-comfortable human's presumably reasonably well-appointed living space -- you can't put a dipole against the wall and hide it behind a curtain! So such a speaker is in practice evaluated essentially as sound-making furniture. Indeed, I recall reading somewhere about someone who largely made the choice between two excellent loudspeakers -- M2 and Salon2, if memory serves -- largely on the basis of aesthetics.

Also, there's a reasonable perception that a luxury-priced loudspeaker should the justify premium price with premium inputs. Those premium inputs can be in the form of luxury materials, SOTA proprietary IP, advanced or rare components, laborious construction or finish, etc. But here, we have, again for over ten thousand dollars after tax, basically a large vinyl-wrapped MDF monkey-coffin with ordinary drivers (a lot of them, sure, but Axiom's drive units, while fine, aren't differentiated with advanced technology in the way one can say, for example, JBL M2 drive units are) and well-optimized but fairly basic engineering (no optimized tweeter waveguide geometry, for example).

The obvious retort is, if it's too expensive people won't buy it, and it will either go away or the price will be lowered until there is demand. And while that is true, it doesn't preclude a value judgment -- especially from those who own loudspeakers in that price range, who've put some thought into these things rather than just kicked the tires.



TBH while I've not been that impressed with the veneer on the Axiom-made Bryston speakers, and I don't imagine Axiom themselves use better stuff than they provide to Bryston.



The Revel Gem2s in our formal living room resemble those remarks.
(And yes, the price of the pedestal stands was galling. But...they look so good on those stands! Nice furniture is expensive.)

Also, hand-applied piano gloss paint fits into the "laborious construction" referenced above. Good paint is expensive to procure and requires some time investment by skilled craftspeople to apply well. So I wouldn't put paint in the same universe as a vinyl wrap.


Oh for sure. But realistically that's a pretty damn lofty price point for loudspeakers. At that price, IMO, a pair of domestic loudspeakers should both be performant and well-appointed!

PS: You mention your new "streamlined" system. Admittedly I haven't yet checked out the website to the 4th ed (sorry - book is heavily read and fantastic as expected though) and maybe what I'm looking for is already there. But if you haven't sketched it out in public yet, I think a lot of people would enjoy reading your thoughts, having "been on the mountain-top," on what compromises you made to streamline for your current environment. Not necessarily component choices, mind. More on a conceptual level.

Beauty is in the eye of the beholder, as it is said. To me the beauty of loudspeakers is in the sound they produce (no surprise), and over the years appearance was whatever it was - within reason. A lot of rectangular wooden boxes, in fact. Now because engineering skills and the science have progressed there are countless options of physical form and materials that can be combined to deliver state-of-the art sound. Scanning laser vibrometers have allowed engineers to design enclosures made of relatively lightweight materials and still not radiate resonant energy. Marble, granite and concrete enclosures are options, but not necessities. Inexpensive particle-board can be made to work just fine - but it might not pass the bogus "knuckle test".

If I were in the market for loudspeakers the KEF Blade One Meta would be a consideration because it combines near flawless sound in what to me is a glorious sculptural package made of polyurethene composite - not wood finished or wrapped in anything. This is a loudspeaker that makes both aural and visual "statements". In dramatic contrast, there is the "bookshelf" Dutch and Dutch cardiod design that in a different setting accurately delivers the entire audible bandwidth within a smallish rectangular package, and to me it would not matter greatly what the exterior finish was - there really isn't much exterior anyway.

Professional monitors have generally been plain black boxes - almost aways black - but the occasional white cone woofers - it's magic! Genelecs are simply well engineered, technically accurate loudspeakers for professionals creating our art, or consumers who find their distinctive appearance attractive. There are more, and more to come I'm sure.

Slide show 6 on the book website shows that basically neutral sound has the potential of being - fingers crossed - a commodity, not the exclusive domain of well-heeled audiophiles and professionals. The loudspeaker whatever it is made of or finished in is no longer the "weakest link" in the audio chain. The room is the remaining thorn in all of our sides - and they are all different.

So, there are "horses for courses" and beauty of different kinds for different beholders.

You asked about my current scaled-down for condo living system. It is in a 13' x 16' x 8' room that I was able to carve out of our spacious condo, because we bought it before it was built. I lived with a 7.4.6 system in California and concluded that it was primarily useful for blockbuster, superhero movies where there is a budget to utilize that number of channels. I seem to have outgrown that category of entertainment, so in this system I began with 7.1 (two subs), leaving elevation speakers as an option. So far I don't miss them, so it may stay as is. I have yet to finesse the calibration of the system beyond level balancing - frankly it sounds very good "out of the box" - the advantage of starting with well designed loudspeakers, Revels in this case - no surprise as I was on the Harman payroll for 28 years . My subs are tiny but potent Paradigm Millenias that don't vibrate (the condo living again) and almost disappear where they are. These days there are many worthy options for loudspeakers.

 

[jim1274]

How might a "serious" omnidirectional speaker have scored, and would Amir have recommended it? I hope we find out some day.

Late to the party here…

I checked and still no “serious” Omni speaker tests done on the forum.

I just sent amirm a DM a bit ago asking if any interest in testing a pair of Duevel Planets Omnis I have listed FS on the forum marketplace. If he shows interest, I’ll modify my ad to give buyer a better deal if willing to send in for testing on the way to the new home. Forum and buyer both win that way.

 

[dualazmak]

But one night I tried a little experiment where I closed my eyes and just started to imagine that I was listening to taller floor standing speakers. As I did this imagination exercise, I experienced the sound staging and imaging gradually lift upwards in my perception until it seemed to match the height I was used to from the floor standing speakers. It was really wild.

As soon as I open my eyes as I recall that illusion vanished.

Yes, this is a really important and interesting aspect of our HiFi audio experiences.
I too sometimes close my eyes, and/or make my listening room almost completely dark for similar miracle feeling and immerse myself in such sound perspectives.

 

[jhaider]

Beauty is in the eye of the beholder, as it is said.

Agreed, but my point isn't really about beauty, but rather correlation of the input and cost. Absent some really amazing and effective proprietary IP, vinyl wrap on MDF just isn't a $10k speaker IMO.

And as an aside, you mentioned the Dutch&Dutch 8c. I would've personally bought Dutch&Dutch 8c's instead of Revel Gem2s for the formal living room, if only Dutch&Dutch had grilles. Those are such great speakers for the use case! And the cabinetry is finished well enough to fit into a formal space with nice furniture. But with 2 young kids (and recently 2 kittens) speakers with no grilles are non-starters. For example, just a couple nights ago one of our youngish kittens swiped at the tweeter dust screen of one of the JBL 708i's we use as an LCR trio in our family room while I was listening. Had that speaker been a KEF Blade or Genelec One, system downtime and an expensive repair would have been the likely results. But thankfully the 708i just shrugged it off.

Slide show 6 on the book website shows that basically neutral sound has the potential of being - fingers crossed - a commodity, not the exclusive domain of well-heeled audiophiles and professionals. The loudspeaker whatever it is made of or finished in is no longer the "weakest link" in the audio chain. The room is the remaining thorn in all of our sides - and they are all different.

Very interesting. Tannoy Precision 6 monitor was the surprise to me--but mostly because I bought a pair of the 8" version long ago and they were so bad as to sound broken (which maybe that pair was).

You asked about my current scaled-down for condo living system. It is in a 13' x 16' x 8' room that I was able to carve out of our spacious condo, because we bought it before it was built. I lived with a 7.4.6 system in California and concluded that it was primarily useful for blockbuster, superhero movies where there is a budget to utilize that number of channels. I seem to have outgrown that category of entertainment, so in this system I began with 7.1 (two subs), leaving elevation speakers as an option. So far I don't miss them, so it may stay as is. I have yet to finesse the calibration of the system beyond level balancing - frankly it sounds very good "out of the box" - the advantage of starting with well designed loudspeakers, Revels in this case - no surprise as I was on the Harman payroll for 28 years . My subs are tiny but potent Paradigm Millenias that don't vibrate (the condo living again) and almost disappear where they are. These days there are many worthy options for loudspeakers.

Interesting all around, thanks. As someone who seems to have never grown into that particular category of entertainment in the first place I installed height speakers for Atmos music and Auro upmixing in our family room rather than for any multimedia content. Admittedly, I've never tried 7.1 without the height speakers on immersive music. Also, alas after deploying ART on the family room system, the living room system (Gem2 and 2 JBL Synthesis S2S-EX subs, with RoomPerfect,

Also, that Paradigm MilleniaSub is an oldie but goodie. It must've been around for nearly two decades now. I didn't even realize it is still a current product. But it provides scads of headroom where music actually has content in a small slim cabinet along with solid low volume extension. I've deployed one behind my desktop monitor for a while now (currently supporting Neumann KH 120 II).

PS: I don't know if you intended the supplemental materials to be behind a paywall-ish, but they are. Or at least there is a "challenge question" related to the book to get access.

 

[MattHooper]

For example, just a couple nights ago one of our youngish kittens swiped at the tweeter dust screen of one of the JBL 708i's we use as an LCR trio in our family room while I was listening.

Sometimes I believe the Internet exists mostly to produce endless reasons not to own cats.

 

[jim1274]

Sometimes I believe the Internet exists mostly to produce endless reasons not to own cats.

Sometimes I believe the Internet exists mostly to produce endless reasons not to own cats.

That’s what metal perforated grills are made for…