Blue or red pill?

[sandyk]

3 hours ago, esldude said:

George Graves 

@gmgravesuses a microphone that has the diaphragms aligned vertically in one package, and he reports his recordings display height.  Maybe he could provide a snippet of one that can demonstrate. 

 

 That could be quite interesting to listen to..

[gmgraves]

3 hours ago, sandyk said:

 

 That could be quite interesting to listen to..

 Let me think about it. I suppose I could send a few interested parties a snippet from one of my symphony recordings via "We Transfer". If I decide to do it, those interested will have to e-mail me and then I'll make arrangements to do a one time mass transfer to all interested parties. BTW, the stacked arrangement of the Avantone CK-40 stereo microphone has nothing to do with the height aspect of the recordings, that;s due to the fact that the mikes are used in cardioid pattern and true X-Y mode. One can have equally good stereo results with a pair of cardioids mounted on a T-bar at any anything from 5" apart to 18" apart (French ORTF). If I make a snippet or so available it will be a symphonic recording made with a pair of Sony C-37P mikes on a stereo T-bar. The mikes are shown below. 

[Audiophile Neuroscience]

1 hour ago, gmgraves said:

 Let me think about it. I suppose I could send a few interested parties a snippet from one of my symphony recordings via "We Transfer". If I decide to do it, those interested will have to e-mail me and then I'll make arrangements to do a one time mass transfer to all interested parties. BTW, the stacked arrangement of the Avantone CK-40 stereo microphone has nothing to do with the height aspect of the recordings, that;s due to the fact that the mikes are used in cardioid pattern and true X-Y mode. One can have equally good stereo results with a pair of cardioids mounted on a T-bar at any anything from 5" apart to 18" apart (French ORTF). If I make a snippet or so available it will be a symphonic recording made with a pair of Sony C-37P mikes on a stereo T-bar. The mikes are shown below. 

 

Please count me in

 

Edit: Actually, count me out. I have already heard it (if  the same music previously sent to me) and yes IMO it does have height information. Busy for the next day or so but will revisit those tracks to confirm my initial impressions.

 

Edit 2: George, no way of knowing if you are talking about the same tracks you sent me previously so lets assume we start from scratch

[esldude]

1 hour ago, gmgraves said:

 Let me think about it. I suppose I could send a few interested parties a snippet from one of my symphony recordings via "We Transfer". If I decide to do it, those interested will have to e-mail me and then I'll make arrangements to do a one time mass transfer to all interested parties. BTW, the stacked arrangement of the Avantone CK-40 stereo microphone has nothing to do with the height aspect of the recordings, that;s due to the fact that the mikes are used in cardioid pattern and true X-Y mode. One can have equally good stereo results with a pair of cardioids mounted on a T-bar at any anything from 5" apart to 18" apart (French ORTF). If I make a snippet or so available it will be a symphonic recording made with a pair of Sony C-37P mikes on a stereo T-bar. The mikes are shown below. 

Count me in too.  I can pm an address when you get ready.

[semente]

9 hours ago, Audiophile Neuroscience said:

So the question still remains can the spatial information in recordings, including depth (if accepted cues are there) be measured?

 

This or a similar question pops up once in a while but I don't really understand what people expect to measure. I'd suggest that it's all happening in your brain and probably depends on speaker listening spot room setup anyway.

[Audiophile Neuroscience]

31 minutes ago, semente said:

 

This or a similar question pops up once in a while but I don't really understand what people expect to measure. I'd suggest that it's all happening in your brain and probably depends on speaker listening spot room setup anyway.

 

i would humbly suggest that everything (all perceived reality)  is happening in your brain. The question remains what triggers it. Environmental influences are one thing - such as speaker position and room interactions - but something must be in the incoming signal in the first place to be subject to environmental influences. The supposition is, if we can hear it, it should be measurable.

 

31 minutes ago, semente said:

I don't really understand what people expect to measure

 

I think that is a good question

[mansr]

6 hours ago, gmgraves said:

I think this is a terrible idea, but a lot of recording and broadcast engineers agree with you. Spaced omnis give a lousy stereo image because they aren't phase coherent. That means, among other things, that you can't mix a recording made with two spaced omnis into mono. Phase cancellations wreck havoc on the resulting mix.

I wasn't suggesting actually using spaced omnis. It's a bad idea for the reasons you explain. I mentioned it only as an example of a non-coincident technique in order to point out that these don't pick up height information either.

[mansr]

9 hours ago, esldude said:

However, some X-Y recordings have the microphones positioned to line up the center of the diaphragms and have one positioned a fraction of an inch above the other.  This means that while the directional characteristics are symmetrical there is a distance difference when sounds originate from an upward or downward direction.  When you have differences of distance you'll get comb filtering.  Such could be in the right frequency range to create a sense of height.  It wouldn't be accurate (except by accident), but it seems to me you'll get a notch in the FR in the right area to trigger height perception. 

I'm not following. If one microphone is placed above the other, sounds from above or below will have a slight phase shift. There is still only a single wave, so there can be no cancellation, and both microphones receive the same strength at all frequencies. This is assuming the sound source is well in front of the microphone pair. If the sound were coming from straight above, the upper microphone would obviously cause some interference or other for the lower one. For any reasonable recording setup, this should not be an issue.

[Audiophile Neuroscience]

13 minutes ago, mansr said:

I mentioned it only as an example of a non-coincident technique in order to point out that these don't pick up height information either.

 

Mans, do you agree there is now evidence that there is L/R lateral as well as depth information recorded in a stereo signal?

[mansr]

7 hours ago, gmgraves said:

Frankly, that amount of vertical displacement is not enough for the microphones to even notice. But what you show above is not an X-Y, pair it's an A-B pair. A true X-Y configuration does not have that vertical displacement. I don't use A-B or Blumlein coincident with separate mikes because there are enough things to worry about when setting-up to do a location stereo recording than worrying about reversed channels (in the above examples, the left-hand mike is point at the right side of the ensemble and vice-versa!). Below, Image #1 is True X-Y and image #2 is Blumlein Coincident.

You must be using different definitions than everybody else. Any coincident configuration, be it XY, Blumlein, or MS, is impossible to realise perfectly since two microphones can't be in the same place. The best we can achieve is an approximation involving some displacement from the ideal position. A vertical separation has the advantage that it behaves correctly for sounds originating in the plane of the microphones. In your lower image, the microphones have instead been moved sideways (or backward along their axes if you prefer). This means any off-centre sound will have a slight phase difference between the microphones, though it is probably small enough not to be a problem. Your first image shows an ORTF configuration. The only other page I can find (using Google image search) featuring it even says so explicitly.

[mansr]

17 minutes ago, Audiophile Neuroscience said:

Mans, do you agree there is now evidence that there is L/R lateral as well as depth information recorded in a stereo signal?

No. Did you read nothing of what I wrote? There is no way to distinguish a near source from a more distant louder one. Any perception of depth or height in a stereo recording is our mind making things up based on what things usually sound like, possibly combined with room reflections. Have you ever noticed how the moon looks bigger when it's low in the sky? That's also our mind applying patterns that are usually right (objects overhead tend to be nearer than objects at the horizon) but fail in this extreme case.

[semente]

1 hour ago, Audiophile Neuroscience said:

 

i would humbly suggest that everything (all perceived reality)  is happening in your brain. The question remains what triggers it. Environmental influences are one thing - such as speaker position and room interactions - but something must be in the incoming signal in the first place to be subject to environmental influences. The supposition is, if we can hear it, it should be measurable.

 

 

I think that is a good question

 

I think that what's coming in the signal is the stereo effect, which results from your brain merging two "snaps" from a slightly different "perspective".

[adamdea]

13 hours ago, Audiophile Neuroscience said:

 

 

Just some other musings. Representation of depth is easily perceived and presumably due to the change in the mic output/amplitude that we hear as loudness.Things further away sound softer and become louder as the source moves closer to the mic. Lateral information is also preserved allowing to sense if the source is approaching from front to back from the left or right. Additionally, moving from back to front the source sound interacts differently with the room, well at least the mic 'hears' more or less "direct" sound or more or less room reflections at different times. This is easily heard and it seems to me that therefore there is depth information as well as lateral information on a stereo recording. I get that this is NOT a new dimension in the mathematical sense and depth would not excite a differential signal with respect to the stereo mics. Nontheless the physical cues are there for depth similar I imagine to stereoscopic depth perception in vision or hearing.

 

Looking at vision (pun), there is a distinction between "dimension" as in 3D and just distance.There are cues for both. So in the recording mentioned above we are picking up distance (depth) cues. Indeed people can still perceive this type of depth with only one eye (Monocular not Binocular).

 

Regarding sound waves most already know our perception of depth and movement results from various changes in amplitude, frequency, inter-aural differences in arrival time. These things can be manipulated in experiments to create illusions of distance, movement and direction. Clearly not all these parameters can be encoded on to a recording but it appears at least enough cues can be to create a convincing illusion of depth.

 

So the question still remains can the spatial information in recordings, including depth (if accepted cues are there) be measured?

 

I'm puzzled by this post, in the light of the your earlier discussion about your background. Have you actually studied auditory perception ie how it works. It's just that I have the impression that you are bit vague about how human beings identify spatial location (especially height, but now we are onto depth). I'm no expert but I'm pretty sure there is nothing like stereoscopic vision for depth perception. So inter aural cues don't help here. Very happy to be corrected if I'm wrong about this. 

 

Of course our primary method of locating sounds is vision. That's why we can get away with one centre channel for film dialogue. IMHO this is a really important point, because it is a complete misdirection to assume that in "real life" we hear the sounds of th orchestra coming from precise locations because of what we are hearing alone.  We hear sounds coming from locations because we know where they are supposed to be coming from. This is not denying that we have processes to locate objects using sound information, but it is an important starting point. 

 

Anyway once you consider how human beings actually localise sounds then you can understand the problem of encoding the information in stereo. Distance cues (which include hf loss through filtering by air) involve some processing and assumptions. When I hear in reviews that when listening to this recording on this amplifier the reviewer can localise all the instruments in a circle in front of him (or some such blather) then I know their imagination is at work. Saying you can by auditory cues tell that the church bell is tolling from 1 mle away is not the same as saying you can tell whether one violin is 25 ft away and the other is 26. The other problem is that the ambient information you get in real life is varied by your hrtf so that you can tell whether/to what extent it comes from front or back.. The omni microphone does not know whether the echo came from front back or side. That is going to make it very difficult to determine distance by comparing direct and ambient information. The information is not unambiguous and its going to be messed around by the effects of the listening room too..

Depth might be perceived for a number of reasons in a recording and in some ways  it can be encoded for gross effects (offstage noises processed to have lots of reverb and hf filtered will sound distant; I don't know whether it can really be done for height at all). But pinpoint depth?.

 

[adamdea]

3 hours ago, mansr said:

No. Did you read nothing of what I wrote? There is no way to distinguish a near source from a more distant louder one. Any perception of depth or height in a stereo recording is our mind making things up based on what things usually sound like, possibly combined with room reflections. Have you ever noticed how the moon looks bigger when it's low in the sky? That's also our mind applying patterns that are usually right (objects overhead tend to be nearer than objects at the horizon) but fail in this extreme case.

Actually there is a frequency shift for really distant sounds, but I agree with the rest. I have no idea what this lateral sound thing means (without a dummy head).

[adamdea]

4 hours ago, Audiophile Neuroscience said:

 

i would humbly suggest that everything (all perceived reality)  is happening in your brain. The question remains what triggers it. Environmental influences are one thing - such as speaker position and room interactions - but something must be in the incoming signal in the first place to be subject to environmental influences. The supposition is, if we can hear it, it should be measurable.

Beyond inter-channel volume and time differences, this gets tricky. It may be a false starting point to assume that there are consistent responses between people to particular recordings beyond from left-right. Maybe not even then as regards precise width.

One starting point might be to consider ambisonics in terms of encoding of information. 

[mansr]

10 minutes ago, adamdea said:

Actually there is a frequency shift for really distant sounds, but I agree with the rest. I have no idea what this lateral sound thing means (without a dummy head).

The attenuation of high frequencies only works for depth location if you know what it sounds like up close. A distant source with more high-frequency content than you're expecting could thus easily be mistaken as being nearer than it is and the other way around.

[adamdea]

1 minute ago, mansr said:

The attenuation of high frequencies only works for depth location if you know what it sounds like up close. A distant source with more high-frequency content than you're expecting could thus easily be mistaken as being nearer than it is and the other way around.

Yes, anyway it's only really relevant over long distances. It may however explain why our model of the world tends to assume that high pitched noises come from closer.

It's really no different to the direct/indirect sound idea ie it's a deduction based on assumptions. It's going to be more reliable if you know what he sound object is and you are familiar with the acoustic.  

[fas42]

9 hours ago, mansr said:

No. Did you read nothing of what I wrote? There is no way to distinguish a near source from a more distant louder one. Any perception of depth or height in a stereo recording is our mind making things up based on what things usually sound like, possibly combined with room reflections. Have you ever noticed how the moon looks bigger when it's low in the sky? That's also our mind applying patterns that are usually right (objects overhead tend to be nearer than objects at the horizon) but fail in this extreme case.

 

Yes, the depth aspect is "made up", in the mind; but it relies on real clues in the recording. Loudness has nothing to do with it; if a sound is softly made close to the plane of the speakers, and a loud version occurs quite some distance back, the sense of the distances remains exactly as that. Room reflections are also irrelevant.

 

How well the key acoustic information is picked by our hearing systems depends entirely on the quality of the replay, especially in the setup's ability not to add too great a level of noise, distortion to low level information. In my travels I have heard the same recordings having zero depth, and a "messy" presentation; versus, tremendous sense of distance, and space, and a complex, rich vista of musical goings on - the only variable has been the level of tune of the rig.

 

People seem to find it very hard to accept that the ear/brain can "see" far greater detail when conditions are right to allow such; whereas it's common knowledge that the eye/brain works precisely so - err, it's all part of the human condition ...

[Ralf11]

On 2/16/2018 at 3:53 PM, fas42 said:

 

I only recently heard Jazz at the Pawnshop - and wondered what the fuss was about ... I have plenty of jazz recordings that are far more 'captivating' than this particular example, in terms of the "spatial experience", and the sense of the whole - guess I just don't have audiophile ears, whatever those strange things are ...

 

can you list them?

 

the fuss is about the SQ - I can't get nearly that SQ on my DSD originals of Buddy Bolden playing live at the Fisk School 

[fas42]

11 minutes ago, Ralf11 said:

 

can you list them?

 

the fuss is about the SQ - I can't get nearly that SQ on my DSD originals of Buddy Bolden playing live at the Fisk School 

 

Depends upon what aspect of SQ turns you on ... what I'm after is getting a sense of the performance being created by living, breathing humans, with all the subtleties that one hears when in the presence of live musicians doing their thing - the FR, hissiness, S/N, pops and crackles, etc, etc, fade as an annoyance, because the feeling of "realness" of the event itself comes through.

 

At the other end of the spectrum is the comical, caricature quality of that type of music as heard in old time cartoons, say. At times played by the 'toon characters using nonsense 'instruments' - which fits, because the quality is that "silly".

[Don Hills]

While the discussion of perceiving height cues is interesting, I fail to see the relevance. I've never been to a performance where the players are stacked vertically.

[Kal Rubinson]

47 minutes ago, Don Hills said:

While the discussion of perceiving height cues is interesting, I fail to see the relevance. I've never been to a performance where the players are stacked vertically.

But the ceiling (or lack of one) is responsible for a portion of the ambiant sound field.

[gmgraves]

12 hours ago, mansr said:

I'm not following. If one microphone is placed above the other, sounds from above or below will have a slight phase shift. There is still only a single wave, so there can be no cancellation, and both microphones receive the same strength at all frequencies. This is assuming the sound source is well in front of the microphone pair. If the sound were coming from straight above, the upper microphone would obviously cause some interference or other for the lower one. For any reasonable recording setup, this should not be an issue.

If one microphone is significantly higher than the other, then you are right. There will be some phase shift. But if the two stacked microphones are almost touching one another, the microphones' vertical pickup patterns are not precise enough for there to be any noticeable or even measurable difference. It's a lot like using two omni-directional microphones in an X-Y, A-B, or Blumlein coincident configuration. The result will be dead mono. There will be absolutely no difference between what the left microphone "hears" and what the right microphone hears. Yet, do the same experiment with two cardioids and you get glorious and real stereo! Now you can use two omnis in the above stereo configurations (all except Blumlein Coincident) if there is a gobo or baffle between the two omni mikes, but even that configuration will only give stereo above the frequency where the size, shape and absorptive characteristics of the gobo determine the frequency at which the wavelength of the sound is above the cut-off frequency of the baffle itself. Ray Kimber's "IsoMike" main baffle is huge, certainly larger than 6 ft in diameter and is shaped like a valentine heart. He gets stereo out of a pair of closely spaced omnidirectional calibration mikes that covers the entire frequency range, but then his recording setup is too huge to be practical. Luckily he had a college auditorium to himself to set up his system.

[gmgraves]

1 hour ago, Don Hills said:

While the discussion of perceiving height cues is interesting, I fail to see the relevance. I've never been to a performance where the players are stacked vertically.

In most concert halls, when the percussionist hits the triangle, it seems to float above the left side of the orchestra. Yes, it's an auditory illusion, but a true stereo mike setup will capture that effect and replay it in ones listening room where it seems to float above the left speaker. Also, usually in most large ensembles, the brass instruments in are in the last row back and usually on risers. That means that they "speak" from higher-up than do the woodwinds in front of them and the violas and cellos in front of the woodwinds. Couple that ability with the front-to-back layering that real stereo imparts and you get the ability to pinpoint each instrument in three dimensional space right-to-left, front-to-back, and height off the floor. When done right the imaging can be jaw-dropingly  uncanny!

[gmgraves]

12 hours ago, mansr said:

You must be using different definitions than everybody else. Any coincident configuration, be it XY, Blumlein, or MS, is impossible to realise perfectly since two microphones can't be in the same place. The best we can achieve is an approximation involving some displacement from the ideal position. A vertical separation has the advantage that it behaves correctly for sounds originating in the plane of the microphones. In your lower image, the microphones have instead been moved sideways (or backward along their axes if you prefer). This means any off-centre sound will have a slight phase difference between the microphones, though it is probably small enough not to be a problem. Your first image shows an ORTF configuration. The only other page I can find (using Google image search) featuring it even says so explicitly.

Let me ask you this: Are your two ears in the same place? And you're right about that phase shift. Not only is it small enough not to be a problem, it's small enough to essentially not exist in such a way that it can be either heard or even measured by any conventional means. Now, above 20 KHz where the wavelengths are in inches or shorter, that might present a problem, but it isn't a practical problem over the audible spectrum.