What is "Sound Stage?"

[fas42]

Now, say it is 1 foot in diamater. The actual sound dispersion pattern from that one foot is probably 5 feet in diameter by the time it reaches your ears at the normal listening postion, hence, you got vertical height of 5 feet top to bottom. However, as you move in toward the speaker, that vertical height narrows down to the diameter of the speaker.

Again, this is a quality of system issue. This could be the behaviour of a conventional system, but will be less and less so the better the overall standard of replay. How this can happen is because the ear/brain AGC, Automatic Gain Control, kicks in: the louder the sound the more attenuated the feed to your brain is, and so when you move around in a room with loud musical sound emerging from one point the subjective impression is that the volume doesn't change very much from one point in the room to another. Gary mentioned a variation of this effect: if something is placed casually between you and the sound source it makes remarkably little difference to the apparent volume.

In the same fashion, when the sound replay of audio has high integrity, the ear/brain is "fooled" into thinking that the volume doesn't change when your head is in the wrong position to receive the direct signal: the off-axis volume "seems" as loud, and hence the soundstage, including height, appears not to change, even when very close to the speaker.

Frank

 

[microstrip]

Please see, at the bottom, a quote the Robert E Greene review of the Harbeths 40:


Another possibility is that more systematically than we suppose record producers really fool us :
(from a review of a Sanders Eros electrostatic speaker, a line speaker with no tweeter height pattern)
At times, with certain recordings such as many tracks from Cassandra Wilson's New Moon Daughter [Blue Note D 112088], the Eros gave the illusion of height to Ms. Wilson's husky, haunting vocals. I'm not sure why the Eros would do this, but it was an intriguing effect. Of course, New Moon Daughter is a studio recording, so almost any sonic effect is possible, and somehow it seemed strangely appropriate that Cassandra Wilson was looming large above me.

 

[treitz3]

Key words...

...height illusion...

All due respect MS...

 

[Phelonious Ponk]

Also, I think a good summary by Bill (with as many examples as possible...and Tim if he wants....would be a nice way to end this thread, the meat of the arguments at the end, a detailed executive summary you might say)....Also, I think a good summary by Bill (with as many examples as possible...and Tim Also, I think a good summary by Bill (with as many examples as possible...and Tim if he wants....

I've summarized this thread a half a dozen times, and what I've gotten for my effort is being accused of being a know it all by those who refuse to know anything. I'm done here, thanks.

Tim

 

[JackD201]

Well, I think this thread still has life left in it.

For example, imagine you have one left an one right individual speaker, thats one round thing on the left and one on the right, say it s full range.

Now, say it is 1 foot in diamater. The actual sound dispersion pattern from that one foot is probably 5 feet in diameter by the time it reaches your ears at the normal listening postion, hence, you got vertical height of 5 feet top to bottom. However, as you move in toward the speaker, that vertical height narrows down to the diameter of the speaker.

Hopefully that does not confuse this issue.

Make that a highly directional horn and I will agree with you on the 5 ft figure. Most domestic loudspeakers will have dispersion far greater. Tall stats (what caused this height brouhaha in the first place) not only throw a cylindrical pattern but do it forward and back. In any case I still agree with you in general that dispersion (plus resulting reflections) AND the summing and cancellation between left and right loudspeakers play a huge part in the illusion of height.

The biggest piece of BS I've read on this thread is that the sense of height is dependent on the tweeter's height because that would assume that tweeter dispersion is purely linear and not conical which can be aimed.

 

[RBFC]

Could some recordings produce more "height illusion" due to a comb filtering of certain frequencies, which are more prominent in some recordings and speakers? Lobing and room reflections must make this a difficult subject since everyone's sonic environment is different when listening........

Lee

 

[JackD201]

Comb filtering does figure into FR notching and how these are processed by the brain as height information so I would say yes.

 

[microstrip]

Key words...
All due respect MS...

Treitz,

All soundstage is an illusion - any basic article on stereo explains it, and the limitations of stereo, and what are the tricks that must be done to enhance the illusion.

But the illusion is based on information collected during the recording and enhanced by experts manipulation. The key question we debate is whether the height illusion is due to the recording properties or exclusively to the artifacts of reproduction, not connected to the recording.

IMHO, if all the drum recordings would show exactly the same pattern of height distribution, the pianos and sopranos would show similar behavior and all the pianos would be similarly tilted I would accept the second hypothesis .

But my humble biased experience and many reports I find suggest otherwise.

 

[JackD201]

Yes for sure, that was just an example of a simple fact that I thought should have been brought up for the defense, that is, although a single speaker can not produce height information on its own, the wavefront it throws allows ones ear to hear the same sound (albeit more or less ampltitude) as one moves about the sphere of the wavefront projected by the speaker. That is a lot of "height info" that has nothing to do with the recording at all. It has to do with where we are at in the soundfield only, and, as I said, if we "direction find" in earnest, we will be able to pinpoint that single speaker, but much sharper pinpointing as one gets very close to that speaker.

Tall stats throw exaggerated vertical images IMO, ie a single guitar sounds like the guitar is 4 feet tall. Now, they also sound so damn nice in the midrange though too. It depends on what you're listening for.

Folks are getting confused about the illusion, vs the well understood science behind the electronics and stereo recording and the speakers/room , and the dog gone MAGIC that is taking place at the ear/brain interface.

I see the same thing over at my sons house. His big screen TV makes everyone squat looking, but no one there notices it anymore..thats how TV looks to them all for years now...its incredible but true. Its the eye/brain thing going on.

When I say to my grandkids hey those people don't look right they are squashed, I get this goofy granddad look that I am all to aware of..ha ah ha. But that is all they know of TV, just like they hate the taste of milk from carboard cartons (they taste the cardboard) but love the taste of milk from plastic bottles ( i taste the plastic taste, to them its natural..)

This thread still is not finished IMO, but I am hoping Bill will come back in and try to do a summary, and I understand Tim is worn down. But, this is one of the most important threads we have had for those who want to understand some of the science of stereo. After all, if we don't understand it 80 years on we are not advanced very far in this hobby.

Tom

You and I agree so much more than you think Tom. The problem is that I never said that all height inferences were recording dependent. What I did say is that there's a lot that can be done to a recording that does provide more powerful suggestions of height. I even said how. It was a lengthy post so forgive me if I refuse to type everything all over again. What I strongly object to is the categorical statement that these are not present in a recording. I think you can't blame me for disagreeing since I have personally done it and have my certification to prove I passed the darned course in which I was taught how. Perhaps it is not as common for music reproduction as it is in film sound reproduction but "not common" is not the same as "not there" or worse "impossible".

We are talking about illusions here. In any illusion you need a willing subject. The eye/ear brain thing is extremely powerful and it works both ways. Depending on your focus you can be either blown away or totally underwhelmed. If you spend all your time looking at your tweeters that's where you're going to perceive where it's coming from. Same thing goes for Binaural. Let yourself go and you get that mind blowing illusion. Focus on what you are hearing from just one ear (like hunting down that crackle or static on that can) and that illusion will collapse quite easily. That's why when working it is imperative to get up, out and come back with fresh ears lest you miss the forest for the twigs.

It took me over a year to actually enjoy a movie without friggin' nitpicking the production values. It's great to know how it is done and to understand the science and engineering. It allows for greater appreciation of the recordings and equipment we own. It does not however enhance enjoyment unless that knowledge is applied for the purpose of getting our darned systems out of the way. In film as in music, if the audience spends more time admiring the sound and not the story, you have not done your job right. Nitpicking on theory does not get the technical aspects out of the way it shifts disproportionate focus on itself, actual attempts at testing those theories on subjects does.

People here are arguing about theory when everyone here has set up speakers and knowingly or unknowingly calibrated the very same factors that aid in the creation of the height illusion. The most common thing to do to increase the sense of height via placement is to bring the loudspeaker further into the room and add toe in. It's quick, it's free. You may not like the over all sound much but if more added apparent height is what you want, you'll get a bit more of it. When you pull the speakers in chances are you're lessening bass, by toeing in more you are changing the filtering pattern and also adding more direct HF down to around 70Hz. It's the psychoacoustic recipe for perceived height. It ain't magic, it ain't rocket science, the papers are published in the medical journals because first and foremost it was a common observation that needed some explaining. The observation always comes before the hypothesis.

 

[RogerD]

Jack, I am listening to my new Ampex preamps tonight and since I first turned them on last Friday I noticed a lot more presence in the sound. Well they have come alive tonight and my psycho speakers are putting out about twice of what I am use to. If there are any ambient cues in the recording I now hear them in spades. I listened to the Miles Davis Tutu album that was tricked out quite a bit and there is information that is at my ceiling and very 3D. Also I listened to a Jimmie Rogers recording made in the early 60's with reverb and other additions, very realistic for the time period.

So cues are in every recording and height is one of them. Even if I turn off my psychos the info is still there and I'm getting this from redbook Cd's,very impressive. FWIW.

 

[fas42]

We are talking about illusions here. In any illusion you need a willing subject. The eye/ear brain thing is extremely powerful and it works both ways. Depending on your focus you can be either blown away or totally underwhelmed. If you spend all your time looking at your tweeters that's where you're going to perceive where it's coming from. Same thing goes for Binaural. Let yourself go and you get that mind blowing illusion. Focus on what you are hearing from just one ear (like hunting down that crackle or static on that can) and that illusion will collapse quite easily. That's why when working it is imperative to get up, out and come back with fresh ears lest you miss the forest for the twigs.

I agree, Jack. Except there are at least 2 levels of illusion, that which you mention and the other, apparently "impossible" by most people's thinking. At the first level you have to "work" on the illusion: sit in the right spot, have the room completely in accord, let yourself "go" using state of mind game playing, alcohol or other "enhancers"; this can be easily disrupted by simply changing focus as you say. But at the second level, the illusion starts becoming rock solid, it is much, much harder to have dissipate: staring at speakers and similar is useless as a means of identifying the source of sound.

I first started to participate on this forum to see how many were achieving this second level of illusion: obviously from the reactions so far it is a tiny, tiny minority. This is understandable because of the difficulty of doing it -- sound barrier, anyone? The shame of it is the almost ferocious antagonism of some to the possibility of achieving such a level of sound reproduction -- there's a smell of an "if I can't have it, then no-one else's gonna have it!!" attitude in this, unfortunately ...

Frank

 

[RogerD]

I agree, Jack. Except there are at least 2 levels of illusion, that which you mention and the other, apparently "impossible" by most people's thinking. At the first level you have to "work" on the illusion: sit in the right spot, have the room completely in accord, let yourself "go" using state of mind game playing, alcohol or other "enhancers"; this can be easily disrupted by simply changing focus as you say. But at the second level, the illusion starts becoming rock solid, it is much, much harder to have dissipate: staring at speakers and similar is useless as a means of identifying the source of sound.

I first started to participate on this forum to see how many were achieving this second level of illusion: obviously from the reactions so far it is a tiny, tiny minority. This is understandable because of the difficulty of doing it -- sound barrier, anyone? The shame of it is the almost ferocious antagonism of some to the possibility of achieving such a level of sound reproduction -- there's a smell of an "if I can't have it, then no-one else's gonna have it!!" attitude in this, unfortunately ...

Frank

Frank all I can say is it's not easy. Tonight I have my jaw on the floor because I have never had my psycho system sound like this. I can't believe there is this kind of information in a redbook CD. I'll have to think about what I am hearing and why.

 

[fas42]

Frank all I can say is it's not easy. Tonight I have my jaw on the floor because I have never had my psycho system sound like this. I can't believe there is this kind of information in a redbook CD. I'll have to think about what I am hearing and why.

Now you've got me curious, Roger! All your efforts of late appear to be in the direction of getting the best from your R2R machinery, a worthy goal, of course; but there doesn't appear to be a direct link with making CD's work better here. Unless, your previous R2R setup was injecting too much interference, noise as you call it, into the playback environment. You know yourself, but it can never be repeated too often: digital sound is very, very fragile. The most unexpected things can drag it down: perhaps you have accidentally "tripped over" something that was causing problems?

If you're saying " I can't believe there is this kind of information in a redbook CD" that means you're actually, finally getting what is on the the disk. CD should completely knock you out with the level of clean detail that's been captured: if you don't, then something's just not quite right ...

Frank

 

[RogerD]

Now you've got me curious, Roger! All your efforts of late appear to be in the direction of getting the best from your R2R machinery, a worthy goal, of course; but there doesn't appear to be a direct link with making CD's work better here. Unless, your previous R2R setup was injecting too much interference, noise as you call it, into the playback environment. You know yourself, but it can never be repeated too often: digital sound is very, very fragile. The most unexpected things can drag it down: perhaps you have accidentally "tripped over" something that was causing problems?

If you're saying " I can't believe there is this kind of information in a redbook CD" that means you're actually, finally getting what is on the the disk. CD should completely knock you out with the level of clean detail that's been captured: if you don't, then something's just not quite right ...

Frank

Frank,

What has changed in my system to cause this? I added a new preamplifier and I use that preamp to run my digital signal. Now what makes that preamp add 50 pct more ambient info? Lower distortion because the nuvistor is a more linear device than tubes or transistors, is my only guess.

 

[JackD201]

I agree, Jack. Except there are at least 2 levels of illusion, that which you mention and the other, apparently "impossible" by most people's thinking. At the first level you have to "work" on the illusion: sit in the right spot, have the room completely in accord, let yourself "go" using state of mind game playing, alcohol or other "enhancers"; this can be easily disrupted by simply changing focus as you say. But at the second level, the illusion starts becoming rock solid, it is much, much harder to have dissipate: staring at speakers and similar is useless as a means of identifying the source of sound.

I first started to participate on this forum to see how many were achieving this second level of illusion: obviously from the reactions so far it is a tiny, tiny minority. This is understandable because of the difficulty of doing it -- sound barrier, anyone? The shame of it is the almost ferocious antagonism of some to the possibility of achieving such a level of sound reproduction -- there's a smell of an "if I can't have it, then no-one else's gonna have it!!" attitude in this, unfortunately ...

Frank

You're the only one I know who's ever claimed to get to "Level 2" Frank. Either you are doing something really special or you are.

 

[fas42]

Frank,

What has changed in my system to cause this? I added a new preamplifier and I use that preamp to run my digital signal. Now what makes that preamp add 50 pct more ambient info? Lower distortion because the nuvistor is a more linear device than tubes or transistors, is my only guess.

Well, just looking at your "2 channel experiment" thread I'm a little confused as to how the signal from the digital is getting to power amps: does it travel via the Accuphase, then the MR70; effectively two sets of preamp circuits? All my experiments have found that absolute minimalisation is crucial for getting best sound: less connections, cables, circuits, power supplies adding to the soup. Since I first started to get "good" sound 25 years ago the one thing I have always never had was a separate preamp component.

Frank

 

[fas42]

You're the only one I know who's ever claimed to get to "Level 2" Frank. Either you are doing something really special or you are.

Not quite unique: Roger, Vince, Robert all have variations of my "thing".

As regards the "something special", as I've said a million times, it's all about being fussy in getting the little things right. Of course, you have to know what you're after, and be able to recognise the signs of whether you're getting closer or further away. The worst part is, at least it's been that way for me, is that the system can actually sound pretty terrible as you edge right up to the point of getting the "good stuff"; I'm sure a lot of people back off when they hear this, thinking they've made a wrong turn. Whereas really they're very close to breaking through, they just don't realise this.

As mentioned a short time ago, Adele's '21' would be an excellent marker: this album will become increasingly hard to stomache as the SQ edges towards that key level: but once over the hurdle the highly manipulated character of the tracks makes sense, it's no longer a struggle to listen to.

Which brings up another identifying characteristic: you can relax totally while listening to the music. Sounds funny, but it's what you do when you listen to live music. Or least I do. In other words, there is no tension in your body as you soak up the sound, it's effortless, requires no concentration or active focus -- the music just is. It's the first thing I do when experiencing somebody's system: register how much I have to tense up to "cope" with the sound. Also how I'm immediately aware when my system is off colour.

So there!! -- double

Frank

 

[bblue]

Bill,

Your answer still mixes directional and positional. The point being debated is positional. You can perceive changes in position independently of having a clear idea of the direction. Once you have a cue that the position changes the listener processing capability will also help to fill the unknowns. And it is here that the perceptual people studies enter. What can we perceive from these little changes in reverberation and frequency response?

But positional as you're using it is merely distance. Distance determines the ratio of the original sound (relative to the mic) and its reverberations, and also will change the tonal characteristic of the original sound as distance is increased. It doesn't matter (to one mic) in which direction that position changes, just that it has changed.

BTW, I can see why the sound recording industry was never interested in these effects – they are too much equipment and listener dependent. But some recordings seem to have clues enough to trigger a systematic acceptable height illusion under some conditions.

No competent studio or mastering engineer will give a **** about the illusion of height because cues for that do not exist in the recording itself. The heighth illusion will depend soley on the projection characteristics of the listeners speakers and characteristics of the room. Depending on the speaker, some will portray a different visual depending on the overall frequency distribution of the recording. HF eq, type and eq of reverberation, time delay effects, and even 2nd and 3rd order harmonics can play a significant role.

Can I suggest that those who claim that height is only a tweeter height effect can easily invert the position of their speakers, or simply turn the speaker 90 degrees keeping the tweeter at the same height and find that the drum set does not turn down? Or just listen to a properly set up Quad ESL63 – a point source speaker.

I for one couldn't possibly do that due to the weight of the speakers. But to your point, re-orienting them may not turn things upside down, but it will certainly change how things appear, both vertically and laterally.

Although we are not robots, people should read what researchers studying localization of sound sources in robotics can do with a single cheap microphone and processing. Some of their software tries to emulate the way humans localize sound sources - and they study and refer to the psychoacoustics papers.

And be sure to include any such observations of height or width in such projects. What they are trying to do, and in a very limited frequency range, is identify and subtract reverberation effects from the original sound for clarity purposes. There would have to be several mics each undergoing heavy DSP to try for directionality in addition to distance (distance position).

Curious that the WBF spellchecker always marks the word psychoacoustics as an error. A signal of the forum official trend?

My spellchecker says it should be either psycho acoustics or psycho-acoustics, but not psychoacoustics. But spell checkers often disagree on spaced versus hyphenated word forms.

--Bill

 

[bblue]

I wanted to quote the above two things from Tom because I agree with both things he said. I listened to a bunch of different music last night and each recording sets its own height. It is not a function of the speakers that creates the illusion, they just have to get out of the way. If it was solely caused by the speakers, each recording would have the exact same height and they clearly don’t.

The bottom line is that whatever manipulations occur when the music is mixed and mastered down to two channels, height information is encoded during the process. Your speakers don’t grow two feet taller for one recording and then shrink down two feet for another. The differences in height among recordings can vary widely.

This thread has basically been the Bill and Tim show where they reinforce each other and lecture everyone with their combined vast body of recording knowledge and how our stereo systems work. The problem is, everything that I have quoted from Bill below is dead wrong. The information that tricks us into hearing height in our soundstage is encoded in the recording.
...

And that is why this thread has been so confusing and contradictory. It’s there. It’s not there. You can hear it, but it doesn’t really exist. It’s your speakers being funky. It’s your room. It can’t be the speakers, it’s in the recording. It’s all phase manipulation. Blah, blah, and blah.

The real truth is that by whatever means it was encoded, each recording sets its own “height” and it varies from one recording to another how much height you have. So stick that in your non-vertical pipe and smoke it.

I see all is well in Storybrook.

It is true that some speakers will produce a different height ILLUSION depending on the recording, but not due to any height cues encoded into the recording by mixing or mastering engineers. It's a simple matter of frequency distribution of the recording, effects such as reverb, time delay, or other time/distance effects used in the lateral field. Frequency distribution (ratio of highs to lows, and which octaves are 'hot') vary dramatically between recordings. Distortion products such as 2nd and 3rd harmonic distortion can play into the effect as well. Some engineers still use the dreadful Aphex Aural Exciter which can do some horrible things to the sound when heard on quality equipment. Used very subtly it can interact with some playback equipment and speakers to different ends.

I agree that the radiation patterns of the drivers can be responsible for a speaker creating a height field higher than it is, but it is not from any 'cues' in the recording, unless you call eq and random effects cues.

So mep, tell me more about the height differences you hear between recordings.

Do they seem somewhat arbitrary in that some recordings have them and others don't?

For those that have height differences is there any bearing to the real instrument positions, or is it just overall vertical size?

If you switch to mono or just one speaker, does the effect go away?

Can you compare the overall tonal sound of the recordings (apart from height or depth). I.E., are the recordings with more high frequency detail the most likely to have increased height?

Do you have any studio recording experience (in the controlroom) with regards to mixing and balancing a project? Mastering room?

Can you give some examples of recordings with 'average' height on your gear, vs some that have greater height?

--Bill

 

[mep]

It is true that some speakers will produce a different height ILLUSION depending on the recording, but not due to any height cues encoded into the recording by mixing or mastering engineers.

Here we go again with the “it’s there, you can hear it in the recording, but it’s not there because of why you think it’s there” rationale. The point is that we do hear height information, it varies from recording to recording, and now we are arguing over how it got there. I think we all know by now there isn’t a knob on the recording console that is labeled “Height illusion.”

It's a simple matter of frequency distribution of the recording, effects such as reverb, time delay, or other time/distance effects used in the lateral field. Frequency distribution (ratio of highs to lows, and which octaves are 'hot') vary dramatically between recordings. Distortion products such as 2nd and 3rd harmonic distortion can play into the effect as well. Some engineers still use the dreadful Aphex Aural Exciter which can do some horrible things to the sound when heard on quality equipment. Used very subtly it can interact with some playback equipment and speakers to different ends.

In another words, it all happens by accident, it’s never intentional on the part of recording/mastering engineers. It’ s just a bunch of random coincidences that happen during the recording process with the end result of hearing height information that was never really recorded in the first place. I’m not one that places much faith in random coincidences that always achieve the same outcome.

So mep, tell me more about the height differences you hear between recordings. Do they seem somewhat arbitrary in that some recordings have them and others don't?

The amount of the height illusion varies from recording to recording as I previously stated. They all have them, some just have more height information than others.

For those that have height differences is there any bearing to the real instrument positions, or is it just overall vertical size?

I have never heard an instrument or voice that sounded like it was placed too high up in the mix such that the illusion of height was unnatural.

If you switch to mono or just one speaker, does the effect go away?

I have a stereo system, so I don’t listen to one speaker. I do play mono jazz recordings and while the sound stage illusion of mono is different than stereo, it still throws a big illusion in my room and I have no recollection of the height of the soundstage shrinking when I play a mono recording.

Can you compare the overall tonal sound of the recordings (apart from height or depth). I.E., are the recordings with more high frequency detail the most likely to have increased height?

I have never contemplated the cause and effect of height information and made any connections between hearing a greater sense of the height illusion and correlating that to hearing more high frequency information. Again, we are not arguing it’s there to be heard, we are now down to figuring out why it’s there in the recording. I think the two choices are:

1. It’s a random coincidence ending in the same result (the illusion of height to some varying degree).
2. EQ, high frequencies, phase tricks, reverb, time delay, distortion or some amalgamation of these causes lumped together for a serendipitous result.

Do you have any studio recording experience (in the controlroom) with regards to mixing and balancing a project? Mastering room?

No, and I never claimed to. One doesn’t need to have experience working behind a console in a recording studio to understand the difference between a good sounding recording and a bad sounding recording or the fact that each recording sounds different from one to another.

Can you give some examples of recordings with 'average' height on your gear, vs some that have greater height?

I didn’t write any of these down on Friday night when I was specifically listening for differences between the illusion of height from one recording to another. I will jot down some notes the next time I feel like concentrating on parts of the illusion instead of just enjoying the music. And maybe there is some correlation to height versus high frequency content. I will listen for that as well.

In summary, I think there is some consensus that whatever height information we hear on our stereo systems is in the recording as you stated in the first paragraph I quoted you on in this response. If it was purely a function of our speakers, each recording would have the exact same height illusion in our rooms which they clearly don’t. The illusion is dependent on the recording. Anybody whose stereo system has the exact same height illusion on every recording, please speak up.