I currently have CD speakers with about 120 degrees of dispersion and the're well away from the side walls. Last week I heard some very wide dispersing speakers similar to the B&W Nautilus: a three way design with minimal baffle for each driver.
It was different from my speakers but still the timbre was pretty good. I think that if you're going to have early lateral reflections, you should ensure they're as broadband as possible to minimize changes to the timbre. Imaging was more diffuse but image shift was minimal, which was unexpected since they were less than a metre from the side wall.
I could imagine a redesigned CBT with improved horizontal dispersion characteristics. I does provide a good solution for the floor and ceiling bounce, which are detrimental to timbre. Unfortunately there is still possible colouration from the front wall reflection of course.
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Matches my observations well. So it is all debated much hotter than actually perceived. And hairs are split over things that might not be told appart or even perceived in a proper blind test.
It is not the reproduction side that we don't understand as Markus said a few posts earlier, it is the perception side in my view. And the brain is very good in trying to make sense out of everything that is being presented. And it just cannot stop it or we cannot stop it. It just does it 24/7. And even if the sound and location are conclusive, we look anyway to be really sure.
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here you go.. the dark, dark, dipole legend is back!
Have you ever calculate the time and level of reflections in a room, and compared them to this?
An externally hosted image should be here but it was not working when we last tested it.
Look. I have nothing against dipoles for relaxing listening. I enjoy electrostatics. But they are not for a critical and accurate listening environment. With the backwave they create a problem. A problem that is one of the causes a baffel is used. Even Toole don't recommend reflections from the frontwall.
With dipoles you will not only have polar lobing, but also early arriving reflections. Your chart is basically confirming that. But even late high gain specular reflections are detrimental. That's one of the reasons diffusion is used behind the listener in an accurate control room.
If you are saying that you have avoided high gain specular reflections without dampening the frontwall, I would like to see an ETC of each speaker.
For listening home you can do whatever you want. It's interesting though that the Behringer came out better then the Orions. I'm not surprised by that. I don't expect a dipole speaker to have a particular good polar response.
This was just an example that the topic isn't as simplistic as you claimed.
Sorry, no. From Toole's "Loudspeakers and Rooms for Sound
Reproduction—A Scientific Review":
"Although the interactions
of loudspeakers and listeners in small rooms are becoming clearer, there are still gaps in our
understanding. A number of these are identified and are good opportunities for future research."
Does that sound like having "a good understanding of spatial reproduction"?
Microphones aren't ears either, right? You're confusing natural hearing and sound reproduction.
Unless you meant specifically 'user desktop', still highly questionable considering Android is built on Linux, then .... uh.... no sir. I've been a regular user since the mid Nineties and even I'm shocked how often Linux shows up beneath the pretty GUIs across the complete spectrum of devices I use every day. It's been ten years since I found a Windows variant, and that device was terrible.
Toole is not the only one who knows something....
But yes, me and you may have a lack of understanding of these and other areas.
I'm talking about the psychoacoustic level. Sure there's research but it doesn't explain what we would need to know to make advances in spatial sound reproduction. Has the conflict between Duplex theory and Theile's association model been resolved? Not that I know of.
No the point is that psychoacoustics itself doesn't have the necessary understanding. I encourage you to read through some of the papers cited by Toole.
Yes you do. You think a speaker's function is to represent an instrument, voice, sound etc. That is not what stereo reproduction is about. You might want to read through Alan Blumlein's stereo patent.
I am just amazed at how much generalization there is in your comment..
An ETC? what for? I have nothing to sell. From how I described the setup and distance from walls, you actually should be able to draw a clear picture without any measure.
You just seem to enjoy opposing wide and accurate, and dismissing the fact that one can get both.
Maybe when you go at the hall, you can pinpoint the 1st and 2nd violins from the string section..
I recommend reading David Eagleman's "Incognito". Chapter 5 is called "The brain is a team of rivals". One headline therein is "The robustness of a multiple-party system".
Both above models could well work in parallel in your brain. Feed each with the right input and it will respond with it's specific answer. There are no clear roadsigns beyond the cochlear nucleus.
Rudolf
WE have to make a distinction between "Constant Directivity" and "Controlled Directivity", I do. I will agree that a monopole is "Constant Directivity" as is a CBT, but neither is "Controlled Directivity" because nothing about the directivity (horizontal in the CBT case) is "controlled" its just Omni. To be "Controlled" one decides what directivity to design for and does that independent of frequency. Now you could say the Omni radiation is what I want and then "Controlled" and "Constant" do become the same thing - that's a grey area of the definition distinctions. But Omni is not what I seek to have and as such no Omni source is "controlled" to me.
As far as the CBT is concerned, reflections are not all of equal importance. Horizontal is responsible for imaging and spaciousness, but there aren't really any good vertical reflections. One can, therefore dampen the floor and ceiling to remove these (as I do), but damping on the side walls will kill the lateral reflections which yield spaciousness. If the loudspeakers are not Controlled Directivity horizontally then the detrimental very early reflections cannot be attenuated without sidewall damping. The near wall reflection is by far the worst because it arrives at the same ear as the direct signal with little delay. The far wall reflection is significantly delayed and arrives at the opposite ear - a far less detrimental effect.
This situation is not by chance. It happens because are ears are located laterally and not vertically. We hear imaging laterally and resolve very accurately laterally. Vertical is all just a nuisance. So the most important thing that a loudspeaker should do is CONTROL the horizontal response - and let the room control the vertical.
If you look at the polar of the CBT prototype I posted earlier, you will see that's very uniform with very little irregularities horizontally. So I don't don't know if there's much to improve actually.
If you are however talking about less horizontal dispersion for less interactions, I believe we're talking about another design. The goal of CBT was different. Horns can have controlled and constant directivity down to about 400 Hz and with a smaller Q. That would be the closest you can get.
But you will end up with more coloration from the room. Imagine the reflections with a speaker that is omni as some frequencies and narrow at others. With no treatment you get reflections where the speakerer is omni and less or nothing higher up. Hence, you have a reflective signal that is very different from the direct signal. This is were the CBT is such an improvement over other designs. The result is not only a great and flat response in the sweetspot but also at other places in the room. It doesn't change very much. How you deal with sidewall and other reflections is up to you. You can pick the spacious Toole response or a more accurate and precise image.
Frontwall reflections from a CBT isn't a problem. The speaker has a baffle.
It will be below -20/-30 dB (depending on distance) with no treatment.Seems like a good, practical approach. With solutions other than a CBT it is very difficult to control vertical reflections because one would need very narrow vertical dispersion over a wide bandwidth. But a typical CBT still has potential problems with an irregular (or too wide) horizontal dispersion and the front wall reflection. Achieving broadband narrow vertical dispersion and moderately-wide horizontal dispersion is virtually impossible I think.
Aiming for moderately wide (let's say 90-120 deg) dispersion and then solving vertical reflections in with room treatment is probably the most economical and practical solution.
Frontwall reflections from a CBT isn't a problem. The speaker has a baffle.
All depends on how much space you have. If it's less than one meter then the low midrange might suffer some colouration from the front wall reflection.
We're drifting away from the original subject I think. But the results of the test were not statistically significant anyway... and I do agree with 6.238 that the differences between wide and narrow dispersion are often less dramatic than most people say, if frequency response and early reflections are flat. The wide dispersion speaker I heard did sound better (less coloured midrange) than a well designed 'naked' dipole when I heard it in a large room. Really made me wonder about the 'benefits' of that rear wave.
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Frontwall reflections from a CBT isn't a problem. The speaker has a baffle.
what is the polar response of the CBT below 500hz?