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omnidirectional loudspeakers = best design available

pozz

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oivavoi

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Looking like cancellations and beaming are starting above 10kHz.
Yap, like I wrote the MBLs don't have perfect dispersion - close but no cigar. The Morrisons are probably more even. Would love to see them measured at ASR. The German Physiks and Duevels have been measured at German magazines, and display uneven dispersion vertically, and somewhat ragged frequency response horizontally over 10 khz or so.
 

anmpr1

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@Mr. Speakers Do you have measurements of omnis? I don't of any speaker that is truly omnidirectional through the entire spectrum.
Conceptually, the Walsh invention would seem hold the most promise, as it consists of a single driver for mids and highs. Ohm never really got it to work as advertised. Morrison is a variation of the Hegeman design. Three way (I think) with passive crossover, conventional mid and HF drivers firing up into a spherical lens.

The MBL site is not exactly forthcoming with technical information, but the large speakers appear to be multidriver with crossovers. Interestingly they claim their wave launch is 180 degrees, but the drivers appear 360. MBL literature mimics the Amar Bose idea of direct/reflective concert hall thing.

Their large speakers are shown in huge 'living rooms' and I imagine that in such large open spaces the speakers do present an impressive sonic artifact. I'm guessing that many ASR readers have smaller listening rooms, and are using the small monitor-type speakers reviewed here, in a nearfield listening position, or possibly larger floor standing speakers in a more normal sized living room.

But consider, if you have twenty or thirty thousand cubic feet of space to fill, small boxes, or even larger floor standing conventional loudspeakers just aren't going to fill the bill. So what are you supposed to do? Obviously in such an environment you are not going to employ a 'critical listening' monitor in an attempt to 'recreate' whatever the recording engineer heard at his console location. But that is not what the buyer of these is probably looking for, in such a large space, is it?

mbl.jpg
 

pozz

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But consider, if you have twenty or thirty thousand cubic feet of space to fill, small boxes, or even larger floor standing conventional loudspeakers just aren't going to fill the bill.
I don't know. Maybe a large dipole or some CBTs. Or a multichannel upmixing system.

Or huge soffit mounted mains. I wouldn't rule out monitors as impractical:cool:

In any case I heard the smaller MBLs in a really small room at a show an they sounded nice. I can't think of an optimal environment for them. I'd have to try some at the ol' homebase before forming an opinion.
 
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FWIW the MBL chart I posted is of in-room measurements. I am guessing that things get a bit tricky with reflections above 10kHz the same way they do with headphones.
 

anmpr1

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I don't know. Maybe a large dipole or some CBTs. Or a multichannel upmixing system.
Yeah. I don't know either. I've not heard them but would guess MBLs have pretty good SPL and are able to cover a large area. The point is, if you are looking to send sound outward into a pretty large domestic-oriented open space, the speakers you are looking for are likely going to be a little different than a typical monitor type, regardless of how good those are for smaller spaces.

Into a huge room (like in the MBL picture) with variable seating options, pinpoint imaging may not (probably won't) be a concern. Filling space with music, especially off axis, is going to be, however. But again, I don't have that kind of space to fill, nor do I have the kind of money to buy MBLs, so I'm just guessing. [If it was me, I'd put a grand piano in the living room and hire a maid that plays.]

However it is, filling a large space is not going to be cheap, but if you live that kind of house, then dollars are likely not a big concern. Drew Daniels (JBL applications engineer) used the company's pro drivers for his home made system. Horn loaded HF, cone drivers for the rest, in a very large box. His space was 40,000 cubic feet, and although his speakers were quite sensitive, in order to fill the room he required a lot of watts. I think it was about two thousand watts per channel for 120 dB SPL peaks at low distortion.

Again, I don't think anyone is claiming that omnis are going to get you that 'in the studio' kind of sound. It's more of what one is looking to accomplish within a given listening space, along with personal taste.
 

pozz

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FWIW the MBL chart I posted is of in-room measurements. I am guessing that things get a bit tricky with reflections above 10kHz the same way they do with headphones.
With nearfield quasi-anechoic windowing (sorry for dropping all those terms at once) you can have fairly clean speaker measurement results down into the several hundred Hz. It's the bass and low midrange that poses issues. The basic idea is that you place a microphone very close (a few mm) to the speaker drivers and measure with a quick sweep (e.g., 5 seconds long to go from 20Hz to 20kHz). Since room reflections are responsible for mangled FR, if you have a short interval of just a few milliseconds where no high-amplitude reflection intrudes, you can cut it out ("window") and have pretty accurate HF, but inaccurate LF. LF will require a separate measurement that is then spliced into the graph. This is what John Atkinson uses to make his graphs. Notice, though, that he does not use the splicing technique for the polar plot, which only goes down to 300Hz.

With headphones, the issue is that the measurement kit has different resonant points compared to human ears. Amir's GRAS kit has good response to around 10kHz, beyond which things become questionable. So the situation is reversed, with bass actually easier to measure than HF.

Sorry if none of this is news to you. The way you asked made me think that an explanation was due.
 

pozz

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However it is, filling a large space is not going to be cheap, but if you live that kind of house, then dollars are likely not a big concern. Drew Daniels (JBL applications engineer) used the company's pro drivers for his home made system. Horn loaded HF, cone drivers for the rest, in a very large box. His space was 40,000 cubic feet, and although his speakers were quite sensitive, in order to fill the room he required a lot of watts. I think it was about two thousand watts per channel for 120 dB SPL peaks at low distortion.
That's pretty cool and makes total sense to me. If I had a large space where I expected a crowd I would probably do something similar with JBL's CBT arrays mounted into the ceiling.
 

gene_stl

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In the mid 1970s I worked for a large audio retailer. One night , after closing, we attended the manufacturer's rollout of the Bose 901 series two, which had a pair of ports shaped like jet afterburners to make the famously inefficient "Bosees" more efficient. There were a lot of Bose company personnel there. Even then , being who I am, I sought out one of the product engineers who was in attendance, because , finally I could get some clarification and questions answered about the "Bose direct reflecting principle"

It was a memorable exchange. Before I was done asking my question the guys face lit up in a smile. He gently explained to me that it was not an engineering principle but a marketing scheme and a service/trade mark. He made it clear that it was essentially all bullshit. He was an honest engineer.

I had not liked Bosees before that and have like them less ever since. This would have been about 1976 or so.
 

Shazb0t

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Well, sure, if you just want to ignore what I wrote earlier that I've actually done those type of tests with my omnis, and the results didn't support your claim.
So the "testing" that you did was able to show that music recorded and mastered in stereo played back on an Omni speaker was like "being at the live performance"? How exactly does that magic work? My point is subjective claims, like the "testing" you've performed, aren't just worthless, but in this specific scenario are also completely illogical. You don't have to agree with me.

There's a reason that science based speaker design and engineering teams with large corporate budgets and a desire to outperform their peers in a highly competitive market aren't pursuing the current Omni speaker technology for stereo reproduction. It's not a conspiracy to stick us all with bad sounding music. You know, Occam's razor and all.
 
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Duke

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There's a reason that science based speaker design and engineering teams with large corporate budgets and a desire to outperform their peers in a highly competitive market aren't pursuing the current Omni speaker technology for stereo reproduction.
My guess is that the focus of large corporate budgets is to make the best-sounding speaker that looks like all of its top competitors. That way the large corporate budget doesn't have to be spent on shifting the public's paradigm to accept something unorthodox. And it may be that the conventional configuration is best for many applications, but that does not mean it is best for all of them.

My point is subjective claims, like the "testing" you've performed, aren't just worthless, but in this specific scenario are also completely illogical.
Don't forget that Toole loved the Mirage M1. Are you going to dismiss his subjective testing in his room, and his claims, as "worthless" and "completely illogical"? Here they are again:

"Over the years, a parade of loudspeakers went through that room, and all disappointed. The room was an unforgiving critic of loudspeakers in which the direct and reflected sounds exhibited different spectra, and conventional forward-firing loudspeakers drew attention to themselves... Then, in 1989, a new loudspeaker came on the scene: The almost omnidirectional , bidirectional-in-phase "bipolar" Mirage M1. They performed well in double-blind listening tests in the small NRC room, and also in this large one. They simply "became" the orchestra. " [emphasis Duke's]
 

oivavoi

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So the "testing" that you did was able to show that music recorded and mastered in stereo played back on an Omni speaker was like "being at the live performance"? How exactly does that magic work? My point is subjective claims, like the "testing" you've performed, aren't just worthless, but in this specific scenario are also completely illogical. You don't have to agree with me.

There's a reason that science based speaker design and engineering teams with large corporate budgets and a desire to outperform their peers in a highly competitive market aren't pursuing the current Omni speaker technology for stereo reproduction. It's not a conspiracy to stick us all with bad sounding music. You know, Occam's razor and all.
If you read the thread one of two pages back I have provided several links to serious studies comparing omnis and other designs, as well as some of the arguments in favor of omnis, which are based on established principles in acoustics and psychoacoustics. How about engaging with those arguments in a serious way?

Also, I don't think anybody on this site thinks that subjective listening impressions are decisive arguments which settle the case. That doesn't mean they don't have any value at all. I don't see any need for throwing around words like "worthless" and "completely illogical". You can make your point in without resorting to that.
 
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Blumlein 88

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My guess is that the focus of large corporate budgets is to make the best-sounding speaker that looks like all of its top competitors. That way the large corporate budget doesn't have to be spent on shifting the public's paradigm to accept something unorthodox. And it may be that the conventional configuration is best for many applications, but that does not mean it is best for all of them.



Don't forget that Toole loved the Mirage M1. Are you going to dismiss his subjective testing in his room, and his claims, as "worthless" and "completely illogical"? Here they are again:

"Over the years, a parade of loudspeakers went through that room, and all disappointed. The room was an unforgiving critic of loudspeakers in which the direct and reflected sounds exhibited different spectra, and conventional forward-firing loudspeakers drew attention to themselves... Then, in 1989, a new loudspeaker came on the scene: The almost omnidirectional , bidirectional-in-phase "bipolar" Mirage M1. They performed well in double-blind listening tests in the small NRC room, and also in this large one. They simply "became" the orchestra. " [emphasis Duke's]
I'm familiar with the M3si, baby brother of the M1. They weren't really close to omnidirectional. Bidirectional and probably wider dispersion than usual is how I'd describe the polar pattern.

Here is the M1si plot from Stereophile.
1609966921075.png


And the M3si plot.

1609966965512.png


A friend briefly owned the M3 and then for several years the M3si. I was able to hear them in three different rooms. One in his first house and two in his second house after moving. If you could find a spot that didn't activate a bass peak they were good. Unlike dipoles where the room wasn't that much activated by the low end, these were just the reverse and it made them a bit more difficult to place well in some rooms. That meant the low end could be very good or it could be very lumpy. I also agree with those who found them dark sounding. Definitely the case to me. I think the bass was a bit over done, and the off-axis drop off with ascending frequency more than optimum. Both of which made it rather dark. Stuffing the ports with those small coffee straws damped the bass down some and improved them in that respect.
 
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Blumlein 88

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If you read the thread one of two pages back I have provided several links to serious studies comparing omnis and other designs, as well as some of the arguments in favor of omnis, which are based on established principles in acoustics and psychoacoustics. How about engaging with those arguments in a serious way?

Also, I don't think anybody on this site thinks that subjective listening impressions are decisive arguments which settle the case. That doesn't mean they don't have any value at all. I don't see any need for throwing around words like "worthless" and "completely illogical". You can make your point in without resorting to that. (surprised that you pressed like on that post, @Blumlein 88 )
Well actually I didn't hit Like or didn't realize it. Was reading on a phone and sometimes scrolling with my thumb I hit like. I'll remove it.
 

oivavoi

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So the "testing" that you did was able to show that music recorded and mastered in stereo played back on an Omni speaker was like "being at the live performance"? How exactly does that magic work?
If I take this up in good faith, there are many valid psychoacoustic explanations for this phenomenon. I'm copying this from something I wrote in an old thread:

"I learnt a lot from this talk on spatial audio by Francis Rumsey (on youtube). In it, he explains why two-channel stereo usually has an inherent artificiality compared to real instruments.

This is how reflections behave given a real stage - if there were actually real instruments at the artificial stereo stage (screenshots from the video):





Each instrument creates reflections, also the instruments in the middle of the soundstage.
But with two speakers, this is what happens:





The instruments between the speakers don't create any reflections. Because of this, two-channel stereo usually doesn't feel "real" to me - and this is supported by some psychoacoustical research into spatial audio.

My experience has been that (good) omnis and (good) dipoles feel less "artificial" than other speaker designs. I suspect the reason is that reflections from the room are coming from many more directions than with conventional speakers, and that this mimics how real instruments behave in a real room."

This is not "magic". It's about the interaction between the speaker and the room. It's not voodoo, it's something that has been described by several researchers. Yes, you can argue that omnis are a bad solution, but there is a real debate to be had here.
 

Blumlein 88

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If I take this up in good faith, there are many valid psychoacoustic explanations for this phenomenon. I'm copying this from something I wrote in an old thread:

"I learnt a lot from this talk on spatial audio by Francis Rumsey (on youtube). In it, he explains why two-channel stereo usually has an inherent artificiality compared to real instruments.

This is how reflections behave given a real stage - if there were actually real instruments at the artificial stereo stage (screenshots from the video):





Each instrument creates reflections, also the instruments in the middle of the soundstage.
But with two speakers, this is what happens:





The instruments between the speakers don't create any reflections. Because of this, two-channel stereo usually doesn't feel "real" to me - and this is supported by some psychoacoustical research into spatial audio.

My experience has been that (good) omnis and (good) dipoles feel less "artificial" than other speaker designs. I suspect the reason is that reflections from the room are coming from many more directions than with conventional speakers, and that this mimics how real instruments behave in a real room."

This is not "magic". It's about the interaction between the speaker and the room. It's not voodoo, it's something that has been described by several researchers. Yes, you can argue that omnis are a bad solution, but there is a real debate to be had here.
Yes, all instruments have the same reflection. Rather than each having its unique one. You can fix that with skillful use of reverb and delay. Doing it separately for each instrument. Fix being relative. You can make it sound better and more real, but never as good as the real thing.
 

oivavoi

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Yes, all instruments have the same reflection. Rather than each having its unique one. You can fix that with skillful use of reverb and delay. Doing it separately for each instrument. Fix being relative. You can make it sound better and more real, but never as good as the real thing.
True. And one may debate how large a problem this is. After all stereo is often defined as a window onto music being played in another room. But omnis (or bi/polydirectionals) behave more like how instruments would behave in your own room. Hence more of the "they are here" impression, less of the "you are there" impression. That may not necessarily be seen as a positive though - it's a question of preference I think.
 

Shazb0t

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My guess is that the focus of large corporate budgets is to make the best-sounding speaker that looks like all of its top competitors. That way the large corporate budget doesn't have to be spent on shifting the public's paradigm to accept something unorthodox. And it may be that the conventional configuration is best for many applications, but that does not mean it is best for all of them.
I disagree completely. If Omnidirectional speakers produced better sounding music playing the market heavily produced stereo recorded/mastered music then large companies would definitely be interested in releasing new products to capitalize on that advantage. Hell, they already try to capitalize on any unreal advantages to the best of their abilities by making all sorts of weird design choices. Let's not pretend that it's uncommon for someone to run an audio company that's heavily based on "woo" while claiming sonic superiority. Haven't you seen that before Duke?

If I take this up in good faith, there are many valid psychoacoustic explanations for this phenomenon. I'm copying this from something I wrote in an old thread:

"I learnt a lot from this talk on spatial audio by Francis Rumsey (on youtube). In it, he explains why two-channel stereo usually has an inherent artificiality compared to real instruments.

This is how reflections behave given a real stage - if there were actually real instruments at the artificial stereo stage (screenshots from the video):





Each instrument creates reflections, also the instruments in the middle of the soundstage.
But with two speakers, this is what happens:





The instruments between the speakers don't create any reflections. Because of this, two-channel stereo usually doesn't feel "real" to me - and this is supported by some psychoacoustical research into spatial audio.

My experience has been that (good) omnis and (good) dipoles feel less "artificial" than other speaker designs. I suspect the reason is that reflections from the room are coming from many more directions than with conventional speakers, and that this mimics how real instruments behave in a real room."

This is not "magic". It's about the interaction between the speaker and the room. It's not voodoo, it's something that has been described by several researchers. Yes, you can argue that omnis are a bad solution, but there is a real debate to be had here.
You need to rationalize how music that is recorded and mastered specifically for STEREO REPRODUCTION would or could benefit by being reproduced on an Omni speaker. You definitely aren't listening to the sound that the mastering engineer was. What exactly are you listening to? Maybe if the music was recorded and mastered in such a way that playing it back in an unknown room on an omnidirectional speaker was the intent, then you could make actual relevant arguments. That's not what you're doing though. If we can't agree on this basic principle then who here is actually acting in bad faith? In fact you're fighting in support of an absolutist obvious troll post. At what point do you realize you're in the illogical camp?

Also, I'm not yet convinced that the speakers you claim are omnidirectional are even capable of playing flat sound in a 360 degree field. I would like to see one of these Madison Audio speakers measured on the Klippel. I think that's a good basis before we even start discussing the potential benefits of omnidirectional sound and how it should be recorded and mastered for playback to realize possible advantages.
 
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oivavoi

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You need to rationalize how music that is recorded and mastered specifically for STEREO REPRODUCTION would or could benefit by being reproduced on an Omni speaker. You definitely aren't listening to the sound that the mastering engineer was. What exactly are you doing? Maybe if the music was recorded and mastered in such a way that playing it back in a room on an omnidirectional speaker was the intent, then you could make actual relevant arguments. That's not what you're doing though. If we can't agree on this basic principle then who here is actually acting in bad faith? Same goes for @Duke and @MattHooper. You're the ones supporting OP's misguided claims, pony up some logical explanations and stop acting like outrage culture victims.
Do you in fact listen to recorded music with exactly the same setup as the recording and mastering engineers? I doubt it. Studio design has gone through several different periods, with different setups dominating at different periods. Here's a good overview: https://www.soundonsound.com/techniques/sos-guide-control-room-design

Some of the music you listen to was probably recorded and/or mastered in a very dry environment. Some of it was done in a lively environment. Some of it was done in a LEDE-environment. Etc. So whatever kind of setup you have in your home, it's almost guaranteed to not be exactly the same as the studio environment of all the recordings you listen to.

Studio people are also not making music on the assumption that it will be reproduced in exactly the same way as they do in their studio. They do it on the assumption that their mixes will "translate" well to a variety of setups. (arguably that has led to many bad recordings lately, given that recordings have to sound good even on crappy bluetooth speakers)

My point is that may be an illusion to believe that our setups in our own home can or should be like an abstract studio setup.

But it's of course fair to say that yes, you strive for creating a studio-ish audio environment in your home, to get as close to as you can to how the mastering engineer heard it. (if you mainly listen to pop music from the 60s, for example, you'll need a different kind of setup than if you mainly listen to current pop music)

For me that's not what hifi is about. Being a primarily acoustic music guy (jazz and classical), my goal is to get recordings and audio setups that can either
a) give me a sense of musicians playing in my own room,
or
b) give me a sense of sitting in a concert hall

My experience is that these two goals require different kinds of setups. For me at least.

But I have no interest in imagining that I am sitting in the chair of the mastering engineer, frankly. But I fully respect that other people may have different goals with sound reproduction! If the primary interest is electronic music, for example, the equation changes, as there is no longer any idea of an "absolute sound" it can be compared to. Then the closest thing might indeed be the mastering chair.

This is about different approaches to high fidelity, audio and sound reproduction in the home, as I see it.
 

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