What is "Sound Stage?"

[JackD201]

Jack, please take the moderator equation out of this. It literally has no bearing whatsoever in this discussion. This is me, unadulterated. BTW, my name is Tom, not Tony but that is beside the point.

The Chesky CD does in fact offer the illusion of height. There are no disputes on that anywhere that I know of. That said, bblue mentioned that it was not a recorded section of normal 2-channel music. I heard height, he heard height and our observations were the same. I have a date with the pillow tonight but I do invite you to read posts past page 11. Possibly many pages past that. I have already asked Bill about this and he answered cordially and appropriately.

Tom,

Forget the moderator thing. You called me on an off topic FYI for a sincere, well meant gesture. Lets leave it at that. Let's just say I don't like being put in my place for behavior that is neither offensive nor detracts anything from an on going discussion being an aside aka BTW. Now if you thought I typed that thinking I did so to curry your favor. That is another matter for I can't think of any other possibility for you to call me on it. As my own FYI to you, just in case, I neither need your favor or crave it. I'm sincerely sorry I got your name wrong and yes that is beside the point. I'm bad with names but nearly superhuman when it comes to faces. It doesn't mean I disrespect people I interact with. If I am working on a short fuse, again I offer an apology. This is a heated discussion (not a bad thing) and I'm only human.

Bill may have been cordial to you but he has not been cordial to others with his choice to express his exasperation with name calling or put downs. If his explanation was sufficient for you and others then good. It doesn't mean it is sufficient for everybody else. For any discussion to go in a positive direction even the most diametrically opposed views must be respected. Fair is fair.

I have been following this and will re-read as you requested. May I ask you do the same. You will see that with the straws from straw men accusations flying. It goes both ways.

 

[Phelonious Ponk]

So take this as a thought experiment: blindfold someone not familiar with the listening room, doesn't know where the speakers are vertically, put him in the sweet spot (that's another argument ...), play back a recording where the sound was recorded coming from a source a foot off the floor, and ask him where he thinks the sound's coming from, to point to it as precisely as he can. Repeat the experiment, this time where the source was 10 feet off the floor when recorded, ask him to point again. Assume for argument's sake he lost all knowledge of what he heard the previous time, or more simply, the 2nd part of this test was done first.

What he point to exactly the same place vertically both times? And if not, why not?

Frank

He probably won't point to the same spot, because the reflections off of the floor are going to change the distance information on the recording. But if you run that test by 20 subjects, they won't all point up. In fact, my guess is they will recognize that one recording is more distant than the other, but will be unable to determine direction. Make one two feet off of a hardwood floor, the other two feet off of a hardwood ceiling, with the mic equidistant, they will sound the same. Make it a sound that the listeners expect to be coming from the floor, they'll point to the floor both times.

No directional information; distance information.

Tim

 

[Phelonious Ponk]

I don't think we actually disagree on much substance, micro. I think our styles are different enough that we sometimes misinterpret each other, but usually, if we just keep talking, we get there. No private wars here, by the way. They're quite public. And bubbling to the surface kicking and screaming every time it looks like this thread might reach the simple, obvious conclusion that there is a sense of height, but no vertical imaging....

Tim

I am beginning to think that the perception of "height" in recordings is affected by our preconceived notions of what we're listening to. In other words, we know where the pieces of a drum kit are usually situated in the vertical plane, and expect to "see" the cymbals at the highest point and the kick drum down below, so we psycho-acoustically place them there. This explanation could account for the differences in presentation described by the various respondents in this thread.

Lee

bingo

 

[fas42]

He probably won't point to the same spot, because the reflections off of the floor are going to change the distance information on the recording. But if you run that test by 20 subjects, they won't all point up. In fact, my guess is they will recognize that one recording is more distant than the other, but will be unable to determine direction. Make one two feet off of a hardwood floor, the other two feet off of a hardwood ceiling, with the mic equidistant, they will sound the same. Make it a sound that the listeners expect to be coming from the floor, they'll point to the floor both times.

No directional information; distance information.

Tim

I would agree with the hardwood floor vs. ceiling variation, that could be very hard to discriminate if everything was perfectly mirror reversed vertically. However such cases in real life are extremely rare: I would suggest that once a listener tuned into the cues on a particular recording, with distinctively different echos in spectral content from the floor compared to the ceiling there wouldn't be indecison. In any case, you are indicating that there is every chance of variation in where a good portion of the listeners point, between the two cases, which is equivalent to those people perceiving a difference in height, vertical imaging.

Frank

 

[RogerD]

I am beginning to think that the perception of "height" in recordings is affected by our preconceived notions of what we're listening to. In other words, we know where the pieces of a drum kit are usually situated in the vertical plane, and expect to "see" the cymbals at the highest point and the kick drum down below, so we psycho-acoustically place them there. This explanation could account for the differences in presentation described by the various respondents in this thread.

Lee

If that is the case all the tens,hundreds of thousands of dollars have been wasted spent on any high end gear. Walmart has plenty tote around players that will fill the bill. With all due respect that idea is flat preposterous. I don't know what brand of BS is being peddled here but it stinks.

 

[JackD201]

If that is the case all the tens,hundreds of thousands of dollars have been wasted spent on any high end gear. Walmart has plenty tote around players that will fill the bill. With all due respect that idea is flat preposterous. I don't know what brand of BS is being peddled here but it stinks.

I wouldn't call it stink peddling but I do not think it is wrong, far from it, but rather just an incomplete explanation of what's going on.

 

[Phelonious Ponk]

I would agree with the hardwood floor vs. ceiling variation, that could be very hard to discriminate if everything was perfectly mirror reversed vertically. However such cases in real life are extremely rare:

Here in thought experiment land, much of what we talk about is extremely rare, if it exists in nature at all. That's the point -- to isolate a phenomenon and see if we can identify it's qualities when separated from other influences. And I would contend that if it would be hard (actually, I contend it would be impossible, but I digress...) to differentiate up from down in the mirrored conditions described above, then there is no vertical information. There is distance information being perceived as vertical through the filter of our expectations.

I would suggest that once a listener tuned into the cues on a particular recording, with distinctively different echos in spectral content from the floor compared to the ceiling there wouldn't be indecison

.

What if the ceiling of the recording space is acoustical tile and the floor is wood? Might the listener interpret those cues and think the soft ceiling tiles are a carpeted floor, the hard floor is a plaster ceiling? Would he then think up is down? What if, as is sometimes the case in studio environments, both surfaces are absorbent? Does the vertical image illusion then vanish?

In any case, you are indicating that there is every chance of variation in where a good portion of the listeners point, between the two cases, which is equivalent to those people perceiving a difference in height, vertical imaging.

No, I'm really not. Given a pure tone, or a recording of a simple sound with no expectation of location, I'm indicating that the two recordings will sound like they are at different distances from the microphone, and listeners will either be unable to choose a direction or their choices will be statistically inconsistent. Given a complex set of sounds with all expectations attached, a drum kit for example, I'd guess that many listeners would construct the vertical image to meet their expectations, with kick drum on bottom, cymbals on top, snare and toms in the middle. But that is all about expectations. The information is distance only.

Tim

 

[Phelonious Ponk]

It does however, in large part, trivialize the human ability to take cues which I maintain are in the recording. Call it phase shifts, recorded ambience or whatever manipulations that can be done to the raw mic feeds or the acquisition of the mic feeds themselves

I haven't heard the Chesky disc, but I don't doubt the possibility of this, Jack. I doubt the commonality. I doubt that this is what people are hearing. I'm not the most studio experienced guy in the world, or even in this thread, but I've spent a lot of time in the places recording music, voice overs, sound effects, and sound for film. And I have never - not once - heard an engineer say he was going to manipulate phase or eq to move A up and B down in the vertical plane. They have their hands full avoiding phase problems and manipulating eq to eliminate congestion and get the tonality they're looking for.

Possible? Sure. Chesky made a tone fly around the room. Destructive to the balance, tonality, realism of the music around it? Probably. You just don't start manipulating phase and eq without effecting everything. Common? No. And not, IMO, what we are talking about here.

Now, can people's ears receive distance cues and can their expectations turn those into height perceptions? Absolutely. And that, IMO, is what we are talking about here.

Tim

 

[Soundproof]

If that is the case all the tens,hundreds of thousands of dollars have been wasted spent on any high end gear. Walmart has plenty tote around players that will fill the bill. With all due respect that idea is flat preposterous. I don't know what brand of BS is being peddled here but it stinks.

Aha, so we invest in high-end gear to reveal a height dimension that conventional stereo has never sought to capture or replay?

There are many reasons why I invest in high-end components: lowest possible system noise, truest possible frequency response, full-range resolution of the signal, believable reproduction of dynamics, excellent interaction between loudspeaker drivers (and quality of same), minimal distortion, and so on.

 

[JackD201]

So we have been agreeing all this time? Because all I've been saying all this time is aside from distance cues, frequency shifts due to distance AND direction as dictated by human physiology and known brain processes help along with the perception of height. Common? No. Possible. Hell yeah. At least with the flying around part. The art is in making the illusion believable. Now I don't want to get into a philosophical discussion about what's real or not real and thus what the truth is or isn't. That's for another thread and I pray it will be a dialectic and not a debate.

 

[fas42]

What if the ceiling of the recording space is acoustical tile and the floor is wood? Might the listener interpret those cues and think the soft ceiling tiles are a carpeted floor, the hard floor is a plaster ceiling? Would he then think up is down? What if, as is sometimes the case in studio environments, both surfaces are absorbent? Does the vertical image illusion then vanish?



No, I'm really not. Given a pure tone, or a recording of a simple sound with no expectation of location, I'm indicating that the two recordings will sound like they are at different distances from the microphone, and listeners will either be unable to choose a direction or their choices will be statistically inconsistent. Given a complex set of sounds with all expectations attached, a drum kit for example, I'd guess that many listeners would construct the vertical image to meet their expectations, with kick drum on bottom, cymbals on top, snare and toms in the middle. But that is all about expectations. The information is distance only.

Tim

I'm with Jack here, I think we're coming to some level of understanding, that there is information on the recording beyond the simple direct sound, which then may be interpreted by the listener in various ways. As regards those scenarios you mention, that would be good fodder for testing, if someone was sufficiently motivated. There is of course the well known visual equivalent, where people wear special lenses that literally turn the observable world upside down. Catastrophic, until the mind suddenly realises what the trick is, and literally in mid-vision flips the world back the right way again.

Yes, if the recording environment was very close to anechoic I believe it would be almost impossible to detect height.

With regard to different responses in pointing, I agree that depending upon the person they may not get the vertical orientation right. But they won't point left or right, they will point at different points in the vertical plane, they will experience the sound as occurring perhaps closer and lower down, or further away which translates to a higher point if you look at the angle of their arm.

Frank

 

[fas42]

Jack and Tom, if a deeper understanding of why the Chesky LEDR "trick" works is wanted this should give you enough meat: http://www.google.com/patents/US4731848. A description of the Spatial Reverberator's -- name gives you the clues, doesn't it? -- operation and intention is given, should keep people busy for a while ...

As an aside, I do have that disk -- I'm going to play some games in Audacity with the track: create a custom version of the key bit, as a sequence of the following, as well as anything else that occurs to me:

L, R
L only
R only
L+R on left only
L+R, L+R

Could tell me nothing, but interesting anyway ...

Frank

 

[microstrip]

I am beginning to think that the perception of "height" in recordings is affected by our preconceived notions of what we're listening to. In other words, we know where the pieces of a drum kit are usually situated in the vertical plane, and expect to "see" the cymbals at the highest point and the kick drum down below, so we psycho-acoustically place them there. This explanation could account for the differences in presentation described by the various respondents in this thread.

Lee

Lee,

Although it can be true, and then we call it a type of bias expectation, it is not what is being disputed. IMHO what is being disputed is the possibility of localization in the soundstage due to clues other than the classically established by the concept of Alan Blumlein - localization due to the delays and relative sharing of direct sound of the sources between microphones without manipulation of the signals.

Although the existence of the clues carrying position information due to different type of reflections in boundaries seems to be undisputed in the XY plane, many people have reserves on its possibility in the Z (height direction). People report they really experiment the sensation of height, and some explanations due to the loudspeaker design and room interaction (referred many time as artifacts) can explain some systematic aspects of height.

Other people report the feeling of height localization not systematically associated with the reproduction system and may be due to information existing in the recording. This captured information is true and transmitted or even enhanced for better perception by some systems - these the so called height cues. This possibility is strongly rejected by many of the posters.

At this point, IMHO, the importance of psycoacoustics in this thread is due to the different mechanisms of localization of sound in hearing in the XY and Z plane. The localization in the Z plane is due to perceived frequency cues created by the ears, involves learning of the individual and different processing mechanisms. All these processes can explain why the vertical localization in sound reproduction depends on minimal cues and any systematic effects in the audio system can destroy them, and some differences between individuals, but not to the point you suggest.

Only experimental data, properly analyzed, could put an end to this debate. Until them, again IMHO, we must accept that stereo achieves localization in 2D, and some people report some form of true Z information, related to the recording, but can not supply at this time evidence enough of it to face the traditional view of tens of years that stereo has no height localization.

 

[FrantzM]

Micro

I am with Lee .. Let's not make things more complicated than they really are. If vertical separation was captured by a microphone then the same mic would be able to capture lateral information and we would not need 2-ch stereo as one speaker would have suffice to reproduce lateral information: it doesn't ...

 

[Phelonious Ponk]

So we have been agreeing all this time? Because all I've been saying all this time is aside from distance cues, frequency shifts due to distance AND direction as dictated by human physiology and known brain processes help along with the perception of height. Common? No. Possible. Hell yeah. At least with the flying around part. The art is in making the illusion believable. Now I don't want to get into a philosophical discussion about what's real or not real and thus what the truth is or isn't. That's for another thread and I pray it will be a dialectic and not a debate.

I think you and I have been agreeing most of the time, yes.

Tim

 

[microstrip]

Micro

I am with Lee .. Let's not make things more complicated than they really are. If vertical separation was captured by a microphone then the same mic would be able to capture lateral information and we would not need 2-ch stereo as one speaker would have suffice to reproduce lateral information: it doesn't ...

FrantZ,

I am deceived, you usually have much better arguments then claiming for simplicity in a complex problem .
You are mixing 2D (XY) with 1D (Z). You can not reverse them - human hearing, soundstage and sound propagation in the acoustic world are not isotropic. BTW, I did not refer to separation - a new word to add confusion if not properly explained.

 

[Phelonious Ponk]

I'm with Jack here, I think we're coming to some level of understanding, that there is information on the recording beyond the simple direct sound, which then may be interpreted by the listener in various ways. As regards those scenarios you mention, that would be good fodder for testing, if someone was sufficiently motivated.

I don't think we're coming to that level of understanding. I think no one in this debate, at least to my recollection, has said that there is no distance information on recordings. Even studio recordings have it (though it is sometimes added artifically). And I think it is obvious, inarguable, that some people "hear" those distance cues as height.

None of that was ever in debate here, in my view. The debate is whether or not any of the "information on the recording beyond the simple direct sound" is captured as, and played back as "height" through any real mechanism. Those of us on this side of the argument posit that it is not, that it cannot, and that if you hear it as height information, you are hearing what you expect to hear, not what is there, which is merely undifferentiated distance information.

That's the debate, and it persists because of the insistence of a few that the effect has nothing to do with their expectations, is not an illusion, but is absolutely real and that if we don't hear it, it is the fault of our ears or our systems, not the limitations of the technology that have been so exhaustively explored here.

It is the same old argument audiophiles always have.

Tim

 

[fas42]

None of that was ever in debate here, in my view. The debate is whether or not any of the "information on the recording beyond the simple direct sound" is captured as, and played back as "height" through any real mechanism. Those of us on this side of the argument posit that it is not, that it cannot, and that if you hear it as height information, you are hearing what you expect to hear, not what is there, which is merely undifferentiated distance information.

So have you had a look at the Spatial Reverberator patent yet, specifically as regards what it seeks to achieve?

FRank

 

[Phelonious Ponk]

I don't think we actually disagree on much substance, micro. I think our styles are different enough that we sometimes misinterpret each other, but usually, if we just keep talking, we get there. No private wars here, by the way. They're quite public. And bubbling to the surface kicking and screaming every time it looks like this thread might reach the simple, obvious conclusion that there is a sense of height, but no vertical imaging....

Tim

So have you had a look at the Spatial Reverberator patent yet, specifically as regards what it seeks to achieve?

FRank

No. Is that something that was linked here? I must have missed it.

Tim

 

[RogerD]

I wouldn't call it stink peddling but I do not think it is wrong, far from it, but rather just an incomplete explanation of what's going on.

Aha, so we invest in high-end gear to reveal a height dimension that conventional stereo has never sought to capture or replay?

There are many reasons why I invest in high-end components: lowest possible system noise, truest possible frequency response, full-range resolution of the signal, believable reproduction of dynamics, excellent interaction between loudspeaker drivers (and quality of same), minimal distortion, and so on.

I am beginning to think that the perception of "height" in recordings is affected by our preconceived notions of what we're listening to. In other words, we know where the pieces of a drum kit are usually situated in the vertical plane, and expect to "see" the cymbals at the highest point and the kick drum down below, so we psycho-acoustically place them there. This explanation could account for the differences in presentation described by the various respondents in this thread.

Lee

What some are saying is that stereo is incapable of producing a accurate spatial recreation of the recording event.....I don't buy it. If a high end system can not recreate the captured illusion accurately to the point of not being able to position the sound of instruments,then that system is severely flawed.