Im pretty certain there a no professionals who disagree with the statement "In an anechoic chamber a good loudspeaker will give near perfect imaging".
No one has shown that it cannot be measured. Just to make it clear no one here has any proof that it can't be measured. I've already shown multiple examples of proof that it can be measured. The proof is the consistent and repeatable results of artificial 2-D and 3-D audio. What do you think they're just flying blind? The proof is 3d acoustical simulations, and the 3d pressure maps that we see generated. If thats not proof enough, what exactly did you expect to see?
again, that's not how it works.
That is not proof; These are things you are putting forth as evidence to support your claim.
Do you say a good speaker won't image in an anechoic chamber?
Are there directional measurement mics that mimic hearing better, for imaging analysis etc.?
Obviously progress has been made since Fletcher et al. (1934), thanks @camplo. Please ai for me (I don't use it for IP and security reasons), how to convert standard 2ch loudspeakers music to binaural headphones music, with stereo imaging of the soundstage in front of me not through or in head? And vice versa, how to convert binaural headphones audio to standard 2ch or multi-channel?
Obviously progress has been made since Fletcher et al. (1934), thanks @camplo. Please ai for me (I don't use it for IP and security reasons), how to convert standard 2ch loudspeakers music to binaural headphones music, with stereo imaging of the soundstage in front of me not through or in head? And vice versa, how to convert binaural headphones audio to standard 2ch or multi-channel?
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A single (neutral) speaker in an anechoic chamber will not do much for perception of soundstage.
Two speakers in stereo will do somewhat better.
A 5.1 surround system will do much better.
Dr. Toole speaks a lot about to this question.
If I could just restate my position.. I'm discussing the potential of a pair of speakers to recreate 'stereo', I'm not talking about the limitations of stereo but the limitations of the speakers and speaker design. That said, stereo is plenty enjoyable when it is done well.
I would say that a pair of speakers will image no worse in an anechoic chamber than in a room. In fact they'd image better in the anechoic chamber in cases where they were not properly designed for the room they're used in.
I would say that a pair of speakers will image no worse in an anechoic chamber than in a room. In fact they'd image better in the anechoic chamber in cases where they were not properly designed for the room they're used in.
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What about dipoles, bipoles, omni, microTower, and LX cardioid (or not).... Would appreciate your insight.
My simple experiment: LX SB65/2.5x10in vintage alnico fullrange wall-hung, imaging all messed up; but pressed against 4cm-thick sound insulator board, super clean and deep soundstage well beyond it. So I bought 7 square meter for anechoic....
Yes, absorbing the wall behind regular speakers can be a good thing.
I don't want to start guessing. These are designed to include the room but if done well, the direct sound should remain balanced. With a dipole you may have a degree of edge diffraction without the plethora of room reflections to back it up, so I guess that's one way it may differ from a regular low diffraction monopole.
...which may serve to break the first ridge of a say 10 m WL if/when interfered by the pointed corner 1 m deep protruding from the wall ( others preceed and will follow to make full effective annihilation)
Yes, in full agreement. Stereo is plenty enjoyable.
Many or most recordings have the venue / studio reflections included in the recording and would have good imaging in your media room at home or in the anechoic chamber.
Personally in my media room I prefer the 6 to 8 foot equilateral triangle setup with the speakers and sweet spot seating. Also in my preference ~ 60% direct sound to 40% room reflections. The room reflections add some space that would be different not better than the anechoic chamber.
Lately I have been enjoying speakers with 100 X 100 degree Controlled Dispersion JBL PT waveguides.
Headphones are a far distant second choice.
Thanks DT
Yep, "quality" of imaging is quite simply tested with how good you can get a phantom center. Using dry sound like mono pink noise it ought to be super compact and concise, middle between the speakers. If it's bloated, like seems to cover the whole area between speakers or even further, you are listening to early reflections and you should shrink the listening triangle. I've found out that in a domestic room without much acoustic treatment listening triangle needs to be about the 6-8ft DT mentions, probably even less. Often referenced 3m listening distance, or what you get when speakers are other side of the room and sofa on the other, it's early reflection fest and imaging is poor. As far as I understand what imaging means.
To get concise center image both L and R sides need to be similar. If setup is asymmetric, or toe-in is haphazard, responses don't match due to generic crossovers and so on, and the image starts to fall apart, starts to go toward the blur fest early reflections also do. When imaging is great, the sound is in the middle, and the speaker themselves seem muted. If there is some hiss left on the speakers, you might be able to reduce the very top end if you wish, check the toe-in again, when the top octave differs the sound localizes to the speakers, fixit and it localizes to the center. But of course do as you wish, this is just a listening test for anyone who is wondering about imaging and whether their system has it or not.
That said, it's fine sound when it's blurry as well, relaxing sound and many people seem to like it. Imaging is fine in sense that what is on the left appears left, singer in the middle, and so on, but it's just blurry and undefined in a way, compared to what it is when closer up. I know that if I move my chair bit forward I get great imaging, and relaxing sound if I move it back a bit, property of how auditory system processes the sound and provides a perception of it and I use it to my advantage. This is great way to adjust your system by the way, use your own auditory system to AB test effect of early reflections to really get to know how they sound like, how they affect the sound you have there.
Of course there is lot of nyance in stereo sound, besides imaging there is apparent source width, spaciousness and envelopment, why not depth, and what ever adjectives one wants to use. These are all different aspects of stereo sound and easily confused between individuals because there is no perception associated with reading or writing a text that describes the perception. It's very difficult to connect perceived sound to written text unless one deliberately goes and finds it out. Goes into deep into listening, experimenting with speaker positioning, and comes up with the descriptions themselves. I mean, it's very easy to understand what imaging is when someone explains it, but how do you know you perceive it when you go and listen to your stereo? Do I have imaging? what's the quality of my imaging? How can I tweak it? What is imaging actually?
Now, anyone whos not done it yet go on your setup and listen, tips above, it's far more important and faster to experiment with listening your own system day on end, than debate this stuff on forum, because the words don't come with perception it's just words. You must come up with the words yourself, from the perception. In the end all that is needed is enough experimenting and resulting listening experience so that one knows what stereo sounds like and what the various terms actually mean. And no, I'm not claiming I know all of it, but I've done some serious listening time and come up on this stuff from inside out so I can quite well connect description to perception, much better than few years a go, and can confidently write posts like this. To a point I think I know what directivity needs to be for the system to work for me in my place in my practical context. I think there is no need for anechoic chamber or special ability to measure it with mic, beyond what measuring one speaker and making sure both speakers measure the same and then go and position the stuff. Measurements would be useful, if the computer could say how to tweak positioning to get it "better", what ever the better was one has to be able to listen to.
Have fun 🙂
To get concise center image both L and R sides need to be similar. If setup is asymmetric, or toe-in is haphazard, responses don't match due to generic crossovers and so on, and the image starts to fall apart, starts to go toward the blur fest early reflections also do. When imaging is great, the sound is in the middle, and the speaker themselves seem muted. If there is some hiss left on the speakers, you might be able to reduce the very top end if you wish, check the toe-in again, when the top octave differs the sound localizes to the speakers, fixit and it localizes to the center. But of course do as you wish, this is just a listening test for anyone who is wondering about imaging and whether their system has it or not.
That said, it's fine sound when it's blurry as well, relaxing sound and many people seem to like it. Imaging is fine in sense that what is on the left appears left, singer in the middle, and so on, but it's just blurry and undefined in a way, compared to what it is when closer up. I know that if I move my chair bit forward I get great imaging, and relaxing sound if I move it back a bit, property of how auditory system processes the sound and provides a perception of it and I use it to my advantage. This is great way to adjust your system by the way, use your own auditory system to AB test effect of early reflections to really get to know how they sound like, how they affect the sound you have there.
Of course there is lot of nyance in stereo sound, besides imaging there is apparent source width, spaciousness and envelopment, why not depth, and what ever adjectives one wants to use. These are all different aspects of stereo sound and easily confused between individuals because there is no perception associated with reading or writing a text that describes the perception. It's very difficult to connect perceived sound to written text unless one deliberately goes and finds it out. Goes into deep into listening, experimenting with speaker positioning, and comes up with the descriptions themselves. I mean, it's very easy to understand what imaging is when someone explains it, but how do you know you perceive it when you go and listen to your stereo? Do I have imaging? what's the quality of my imaging? How can I tweak it? What is imaging actually?
Now, anyone whos not done it yet go on your setup and listen, tips above, it's far more important and faster to experiment with listening your own system day on end, than debate this stuff on forum, because the words don't come with perception it's just words. You must come up with the words yourself, from the perception. In the end all that is needed is enough experimenting and resulting listening experience so that one knows what stereo sounds like and what the various terms actually mean. And no, I'm not claiming I know all of it, but I've done some serious listening time and come up on this stuff from inside out so I can quite well connect description to perception, much better than few years a go, and can confidently write posts like this. To a point I think I know what directivity needs to be for the system to work for me in my place in my practical context. I think there is no need for anechoic chamber or special ability to measure it with mic, beyond what measuring one speaker and making sure both speakers measure the same and then go and position the stuff. Measurements would be useful, if the computer could say how to tweak positioning to get it "better", what ever the better was one has to be able to listen to.
Have fun 🙂
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Which preamp is the one that totally improves the "image"? Is there only one on the market? Is it expensive or inexpensive?
So, to what characteristics of the soundwaves entering your ears, would you ascribe as the source of "great imaging" vs "blurry and undefined", given that only the chair was moved "a bit forward" or "back"? Do you think reflections made that much difference, seat forward/back a few inches? (Easy to confirm/falsify: change only reflections.)
What characterisics of the soundwaves entering one's ears made imaging great?
Not really. It's possible on much modern equipment to just play the track/album again... 😉
wchang, It's combination of all thigns that matter, I do not know what they are specifically. Could be some particular early reflection, or just all of them plus number of other things. Many things change as listener moves closer to speakers: direct sound gets louder compared to room sound in general. Specular early reflections get to higher angle both regarding speaker directivity and HRTF. So getting closer early reflections get attenuated by directivity while also delay is increased which also introduces extra attenuation compared to direct sound.
Most accurate description I have found of what happens perceptually is David Griesinger papers about Auditory Proximity so it would be Limit of Localization distance, so I think it's exactly that what is happening, so description and mechanisms explained in his papers.
As I understand it, what happens here, is that when auditory system gets sufficiently high amplitude peaks to identify a sound source, basically periodic amplitude peaks that result from all harmonics of a sound be in phase at every fundamental cycle making huge constructive amplitude peak stick out above all the sounds entering ear, auditory system promotes the sound source to it's own neural stream giving your full attention to it. This improves localization and clarity for it, makes the sound more involving in general. All the other sounds are now in a separate background stream, which would be the envelopment. One can affect the periodic amplitude peaks by preserving / ruining phase in the playback, and the noise part is just all noise in the room including any background noise and noises of the system that hamper the harmonics. Perhaps some distortion harmonics could even increase the harmonics and resulting amplitude peaks resulting "better sound". All kinds of things affect this same phenomenon to happen in auditory system.
Basically, in a small room early reflections are really loud and close after direct sound reducing this SNR auditory system uses to detect nearby sounds, and the focus is lost. All sounds are now in one neural stream and there is no attention to it, there is no clarity or precise localization and everything is just bit hazy over there kinda thing perceptually. This is feature of auditory system, which can be exploited very easily with positioning, just shrink the listening triangle until the perception changes, early reflections change enough brain provides the attention. Sometimes you want this attention and sometimes not, and you'd just move a bit to be what you want. In general this causes a lot of confusion on gear talk as it's fundamentally auditory system thing, and not gear spesific. In my opinion state of auditory system should be always somehow communicated, otherwise it's confusing for those who cannot read it between the lines.
What goes to measurement, if I take measurement both sides of the physical location perception changes, there is not that much of a difference. I definitely could not say what makes it looking at the graphs, perhaps all data combined has the information baked in, but it's just easy to listen, no need to measure.
This auditory proximity is feature of our auditory system, and not spesific to stereo systems, and happens in real time in real life all the time, we just don't pay attention to it. With stereo, you just accommodate to the auditory system.
Most accurate description I have found of what happens perceptually is David Griesinger papers about Auditory Proximity so it would be Limit of Localization distance, so I think it's exactly that what is happening, so description and mechanisms explained in his papers.
As I understand it, what happens here, is that when auditory system gets sufficiently high amplitude peaks to identify a sound source, basically periodic amplitude peaks that result from all harmonics of a sound be in phase at every fundamental cycle making huge constructive amplitude peak stick out above all the sounds entering ear, auditory system promotes the sound source to it's own neural stream giving your full attention to it. This improves localization and clarity for it, makes the sound more involving in general. All the other sounds are now in a separate background stream, which would be the envelopment. One can affect the periodic amplitude peaks by preserving / ruining phase in the playback, and the noise part is just all noise in the room including any background noise and noises of the system that hamper the harmonics. Perhaps some distortion harmonics could even increase the harmonics and resulting amplitude peaks resulting "better sound". All kinds of things affect this same phenomenon to happen in auditory system.
Basically, in a small room early reflections are really loud and close after direct sound reducing this SNR auditory system uses to detect nearby sounds, and the focus is lost. All sounds are now in one neural stream and there is no attention to it, there is no clarity or precise localization and everything is just bit hazy over there kinda thing perceptually. This is feature of auditory system, which can be exploited very easily with positioning, just shrink the listening triangle until the perception changes, early reflections change enough brain provides the attention. Sometimes you want this attention and sometimes not, and you'd just move a bit to be what you want. In general this causes a lot of confusion on gear talk as it's fundamentally auditory system thing, and not gear spesific. In my opinion state of auditory system should be always somehow communicated, otherwise it's confusing for those who cannot read it between the lines.
What goes to measurement, if I take measurement both sides of the physical location perception changes, there is not that much of a difference. I definitely could not say what makes it looking at the graphs, perhaps all data combined has the information baked in, but it's just easy to listen, no need to measure.
This auditory proximity is feature of our auditory system, and not spesific to stereo systems, and happens in real time in real life all the time, we just don't pay attention to it. With stereo, you just accommodate to the auditory system.
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I like to split my direct/reflected by time. Maximise late and minimise early. That way the room doesn't get mixed into the performance but it's comforting to know it's there.
I'm not adason but possibly a preamp with unattenuated very high frequency response, or even up-tilted response (remember moving-coil phono cartridges). I once compared very carefully different 12AU7 input tubes and the chrome-plate Siemens imaged much more pin-point than Telefunken which was more realistic sounding (I would say natural/accurate/flat). Equipment: Quad CDP99, Unico hybrid integrated amp, Fostex F120A with large Eskmo electrostatic supertweeter.
Thanks, but what could have changed so significantly when the seat was moved forward/back only a little? How small a forward/back seat adjustment could still make a significant difference in "great imaging"? (IME, an inch or two.)