What is "Sound Stage?"

[Phelonious Ponk]

Tim,
Please do not change the sense of my sentence cutting part of it:

the room ..... should conjugate with the recording to recreate the sound engineer’s intentions.

is not

I think no one here believes that the room pretends to create an acoustical environment per se– it should conjugate with the recording to recreate the sound engineer’s intentions.


Any way, my idea is that during mastering the sound is often tailored for a different sound environment, in order to better recreate the sound experience in the final consumer room. (or unhappily for most of us for the car or kitchen radio) .

Some people spend their lives studying sound reproduction. They write articles and books on it and some even write there things like Readers will undoubtedly find conflicts between the recommendations in this book and the ideas published or promoted elsewhere Some others just know the truth by other means. I currently have made my choice which school I prefer, may be someday I will change ...

Sorry, Micro. I didn't really mean to take you out of context, I thought in this phrase:

it should conjugate with the recording to recreate the sound engineer’s intentions.

...that "it" referred to the room. My apologies if I misunderstood.

Tim

 

[NorthStar]

Again, there is no notion of height produced by a loudspeaker. None.

What you're describing in the first paragraph is an out-of-phase pan from left to right. You ears are hearing height when in fact the signal is simply out of phase. Some will hear it as having no particular 'place', some will hear it as behind them. Out of phase signals in live recordings are a product of reveration signals of the room adding and subtracting, they don't imply height. Often, special effects on pop recordings will include some phase shifting/out of phase panning for effect. Again, no height implied. In some sessions, out of phase signals are a mistake -- the engineer didn't recognize them for what they are and correct them, or liked the effect. Most likely to occur in drum sets that have many mics.

I checked all the Chesky test discs track list and explanations of the test. There are NO references to height, except the seating height of the listener. There are a variety of others, including phase sweeps, out of phase channels, etc.

So if you're hearing height during playback:

1. Your ears could be (mis)interpreting the out of phase signal as height,
2. Your speakers are misaligned or positioned incorrectly,
3. It's a room artifact based on where/how you and the speakers are situated.

But be thankful you're hearing *some* effect. I've known studio engineers that could not even hear phase, or out of phase speakers. That's a sad state.

--Bill

Interesting Bill. But what about the sound reverberations from the ceiling?
...In some Classical Organ recordings, Chorals, Classical Operas, etc.

And what about a recording like from 'Master and Commander - The Far Side of the World', and also from 'We Were Soldiers', both with recorded and fully divulged Height information from just plain horizontal speakers?

- Phase is another thing. It confuses us sideways.

- Chesky recordings is also another thing. Studio.

* The technics employed to record and produce Height information are various, and they are real, and they are also accidental. And we can hear it. ...In some music, and movies recordings.
And that is my humble opinion, and factual observation (hearing).
As a Music lover, an audiophile (passive & active), a musician, a recordist, a technical sound assistant engineer, and all that Jazz ... :b

 

[treitz3]

Again, there is no notion of height produced by a loudspeaker. None.

What you're describing in the first paragraph is an out-of-phase pan from left to right. You ears are hearing height when in fact the signal is simply out of phase. Some will hear it as having no particular 'place', some will hear it as behind them. Out of phase signals in live recordings are a product of reveration signals of the room adding and subtracting, they don't imply height. Often, special effects on pop recordings will include some phase shifting/out of phase panning for effect. Again, no height implied. In some sessions, out of phase signals are a mistake -- the engineer didn't recognize them for what they are and correct them, or liked the effect. Most likely to occur in drum sets that have many mics.

I checked all the Chesky test discs track list and explanations of the test. There are NO references to height, except the seating height of the listener. There are a variety of others, including phase sweeps, out of phase channels, etc.

So if you're hearing height during playback:

1. Your ears could be (mis)interpreting the out of phase signal as height,
2. Your speakers are misaligned or positioned incorrectly,
3. It's a room artifact based on where/how you and the speakers are situated.

But be thankful you're hearing *some* effect. I've known studio engineers that could not even hear phase, or out of phase speakers. That's a sad state.

--Bill

Yes, Bill. I'm definitely hearing an effect. Allow me to clarify a bit on where this test is on the Chesky disc. It is section 11, which is the LEDR test. I hope I don't get into trouble posting this but I will take what is written in the liner notes and post it here, so that you can see what it is I'm talking about.

11. The LEDR [trademarked] Test

LEDR (Listening Environment Diagnostic Recording) is a remarkable tool developed by EASI to test stereo systems and their interaction with the room. It is the world's first objective stereo imaging test, generated via a computer program developed at Northwestern University.

Use the LEDR test to help locate reflecting surfaces in the listing room that degrade a stereo image. For example, the first LEDR path is UP. If the sound does not rise up from the loudspeaker, there may be ceiling reflections that could be alleviated with absorption or diffusion. Here are the LEDR paths (each one is announced).

1) UP: Sound starts at the left speaker and rises straight up about 6 feet. This path is repeated from the right speaker.

2) OVER: Sound starts at the left speaker, arches overhead and down to the right. This path is repeated from right to left. The arch should be unbroken, smooth, symmetrical and its highest point at least as high as the UP paths.

3) LATERAL: This signal is divided in four parts. First sound travels from left to right speaker. Then it moves from beyond the right to beyond the left. Third, from right speaker to left. And last, from beyond the left to beyond the right.

Again, if you have any problems reproducing any part of the LEDR test, look for interfering room surfaces in the direction of the distortion.

Depending on what room my rig has been in, I have achieved great results to rather poor results

So if you're hearing height during playback:

1. Your ears could be (mis)interpreting the out of phase signal as height,
2. Your speakers are misaligned or positioned incorrectly,
3. It's a room artifact based on where/how you and the speakers are situated.

First off, if I am misinterpreting the out of phase signal as height, I'm glad to be misinterpreting. No doubt about that in my mind at all. My speakers are aligned using various methods and are measured for level/tilt, distance between relative space between the speakers and listening position, distance to sidewalls/back walls, etc. down to within an 1/8 to 16th of an inch for all aspects. My favorite method is using the Sumiko setup, so while I could be wrong, I very seriously doubt my speakers are misaligned or setup improperly. As for it being a room artifact based on where/how you and the speakers are situated, thank you for pointing this out.

I was scratching my head to the point of baldness last night when you said it wasn't the speakers that produced the height, when this was clearly what I heard. I had it backwards. I thought the speakers produced the sound and the room cancelled it out. You were correct, it apparently is not the speakers and it is the room. I must take the time to thank you for pointing this out to me and I must also take back what I had mentioned as fact a couple of pages back [here's the link...http://www.whatsbestforum.com/showt...Sound-Stage-quot&p=88862&viewfull=1#post88862 ].

I must admit, this is a room interaction that I find pleasing. All this time, I thought it was the speakers doing the work. I guess you learn something everyday.

 

[JackD201]

Again, there is no notion of height produced by a loudspeaker. None.

What you're describing in the first paragraph is an out-of-phase pan from left to right. You ears are hearing height when in fact the signal is simply out of phase. Some will hear it as having no particular 'place', some will hear it as behind them. Out of phase signals in live recordings are a product of reveration signals of the room adding and subtracting, they don't imply height. Often, special effects on pop recordings will include some phase shifting/out of phase panning for effect. Again, no height implied. In some sessions, out of phase signals are a mistake -- the engineer didn't recognize them for what they are and correct them, or liked the effect. Most likely to occur in drum sets that have many mics.

I checked all the Chesky test discs track list and explanations of the test. There are NO references to height, except the seating height of the listener. There are a variety of others, including phase sweeps, out of phase channels, etc.

So if you're hearing height during playback:

1. Your ears could be (mis)interpreting the out of phase signal as height,
2. Your speakers are misaligned or positioned incorrectly,
3. It's a room artifact based on where/how you and the speakers are situated.

But be thankful you're hearing *some* effect. I've known studio engineers that could not even hear phase, or out of phase speakers. That's a sad state.

--Bill

Curious that you would say that. There are many ways from mic placement to the mixing desk where the height of the sound source can be manipulated. In the case of mic placement, yes, it does employ phase manipulation as one can use the differing characteristics at differing degrees of the polar pattern but you don't have to be out of phase. Think Doppler. A loudspeaker should be able to reproduce this. In a good room, that Chesky track should move in an arc.

Acoustically, image height can be manipulated as well. It isn't difficult either for as long as propagation isn't visualized as beams.

 

[treitz3]

I'm getting a little more clarity on the subject, the more I research it. Bill is correct and I was admittedly incorrect, just based upon what I have learned. Just for a quick example, here is a clip from Stereophile's article...

Although many audiophiles would insist that their systems do reproduce a sense of height, when I have experienced image height, it has nearly always turned out to be spurious, due to system flaws. The fundamental problem is, you see, that nearly all the microphone techniques recording engineers use to record music are incapable of capturing any height information.

A common philosophical trap fallen into by audiophiles is to assume that any LP or CD inherently contains within it the information necessary to recreate the live illusion. This just isn't correct. Even the finest system will not create a soundstage with an accurate sense of height unless care was taken to ensure that the appropriate height information was captured at the recording session.

He does go on to say...

I am not saying that it is impossible for a stereo system to throw a sense of height—the new Chesky Test CD that I mention in my loudspeaker reviews this month contains tracks where the signal can reproduce as being above the plane of the loudspeakers—but that conventional stereo microphone techniques do not capture the aural clues that allow the ultimate listener to perceive height.

You can read the full article here >>> http://www.stereophile.com/asweseeit/390awsi/index.html

The Chesky CD he is referring too is the same one I linked earlier on. You can read more about the LEDR here >>> http://www.stereophile.com/features/772

 

[JackD201]

With all due respect to JA, JGH and LA, vertical placement can be achieved. It can be achieved by making use of the polar responses and can be achieved at the mixing console. It's even taught in recording schools. engineering schools. In a nutshell both make use of FR manipulation to trigger evolutionary psychoacoustic responses. Look at it this way. We are adapted to hear best in the horizontal plane. Our pinnae our shaped that way. As a result lifts in HF components of events will cause an interpretation of added height. Lifts in LF components of an event will cause an interpretation of lessened height or grounding. Take a bass guitar that is normally panned center along with the kick drum. If you want them to stack up and not occupy to much of the same space resulting in the lack of articulation you can favor or cut response either through mic placement or EQ to do so.

 

[Soundproof]

@Jack - I don't see a contradiction here. Most instruments capable of producing bass-information are "grounded" in the mind's ear, most instruments and voices that create mid-tone/treble information are "raised" in the mind's ear. When you boost LF or increase HF, you are assisting this built-in interpreter in localizing the sound sources.
As most loudspeaker systems also have the bass at the bottom and the midtone/top at the top, this separation of sources is further assisted mechanically by the system.

But we are not capturing vertical information with conventional stereo miking, and are reduced to having to play with the signal in order to create vertical illusions - something I'd actually prefer wasn't done, to be honest, as it affects the entire reproduction.

 

[MylesBAstor]

You know, if I started believing some of the things you guys have said, it wouldn’t be that far of a leap to say that stereo actually reproduces no sound and its but a figment of our imagination that we hear anything at all.

Mark, as usual, you have a knack for hitting the nail on the head. For someone to say there is no such thing as image height tells me that they've never heard a good high-end speaker or system.

Every recording, every speaker, every cartridge, every component in the room, affect imaging and image height. Some even exaggerate it. Other components make a recording sound like The Lilliputian Symphony Orchestra or Schroeder's piano. On a good recording, you should be able to see in the mind's eye where the singer was relative to the mike. That's esp. true for line source speakers in my experience. And yes, you can not only hear and feel the side walls but the ceiling. It should be made obligatory for everyone who talks about anything in audio to go to HPs to hear what a truly great high-end system can do. Until then, most have no idea what they're talking about.

 

[Soundproof]

I find the "they've never heard a good high-end speaker or system" statement to be extremely boring, and uninformative. It is the card shown when arguments fail against technical facts. It presupposes that others participating in the discussion have not heard good systems, and is a silly presumption.

I'm presently planning and spec'ing a listening room that is going to be 15 feet high, 21 feet wide and 48 feet long, with a very low noise-floor, in order to achieve a very engaging soundstage - where the illusions of depth, verticality and disappearing side walls will be excellently taken care of - through steely eyed acoustical science, instead of smoke-and-mirrors.

 

[treitz3]

For someone to say there is no such thing as image height tells me that they've never heard a good high-end speaker or system.

I don't recall anybody saying that. I have height in my rig and it's undeniable. They are just saying that it's not the loudspeaker that's doing it and that it's in the recording technique. I will admit, it does seem that some loudspeakers offer the illusion of better height but as I am learning, it may just be more of a room interaction rather than the ability of the loudspeaker itself.

 

[mep]

You will still need the smoke and mirrors that occurs at the mixing console in order to play music in your steely-eyed acoustical science designed listening room.

 

[JackD201]

@Jack - I don't see a contradiction here. Most instruments capable of producing bass-information are "grounded" in the mind's ear, most instruments and voices that create mid-tone/treble information are "raised" in the mind's ear. When you boost LF or increase HF, you are assisting this built-in interpreter in localizing the sound sources.
As most loudspeaker systems also have the bass at the bottom and the midtone/top at the top, this separation of sources is further assisted mechanically by the system.

But we are not capturing vertical information with conventional stereo miking, and are reduced to having to play with the signal in order to create vertical illusions - something I'd actually prefer wasn't done, to be honest, as it affects the entire reproduction.

Agreed. Assisted being the operative word. In an earlier post I mentioned that this "assist" could be accomplished with mic placement, particularly by exploiting the variations in frequency in varying degrees of its polar pattern dictated by the tangency to the diaphragm. This gives what one might call a recording perspective analogous to a viewing angle.

While we do not capture vertical information per se, I feel it does not mean there is no vertical component to the reproduction with regards to the phantom images, which is really all I'm saying. Very different from mono from one loudspeaker which I must say has its charms. We know that when we move around we alter the "viewing angle". If we move the loudspeakers we change it as well just like moving a mic around but in reverse.

 

[JackD201]

I don't recall anybody saying that. I have height in my rig and it's undeniable. They are just saying that it's not the loudspeaker that's doing it and that it's in the recording technique. I will admit, it does seem that some loudspeakers offer the illusion of better height but as I am learning, it may just be more of a room interaction rather than the ability of the loudspeaker itself.

I am not in total agreement treitz. Some speakers just have squat stages no matter what music you play on them so I'm inclined to believe the speakers must have some contribution. I will plead the fifth on which of these I've heard.

 

[mep]

I am not in total agreement treitz. Some speakers just have squat stages no matter what music you play on them so I'm inclined to believe the speakers must have some contribution. I will plead the fifth on which of these I've heard.

I won't. Quad ESL-63s.

 

[bblue]

And you we should think that is by fortuitous hazard that in some rooms, some of the recordings we consider coming from great sound engineers can achieve this effect systematically ? That these people were not aware of this capability of stereo? Should we consider that this picture, from
http://www.linkwitzlab.com/reproduction.htm
is an exaggeration and the orchestra should be squeezed in half, between the speakers ?

BTW, the soundstage exceeds the speaker to speaker distance in the recording of Belafonte at Canegie Hall , both in CD or LP. in many systems. Any special reason for that?

You may have noticed that my last few comments about recording, mixing layout and space between channels was studio-centric. Meaning that it had to do primarily with in-studio recordings where the environment is 'created'. Not live-mic'd and recorded all at once with an attempt to create a live sound stage.

Live recording is another matter which I touched on earlier. With simple micing (2 mics carefully placed or in some cases very cautiously positioned and balanced multi-mic setups) an astonishing realistic soundstage extending beyond L&R can be created. It will be strongly based on the room characteristics, mics chosen, electronics -- all the usual things. In this case what the mics are hearing are a complex relationshiip of sum and difference signals (phase shifting) which can create the illusion of great space in a listening environment.

For example, due to reverberation in the room/hall you have the direct sound and the reverb mixed together acoustically, if a signal from an instrument on the far right side is 'heard', its direct signal will place it on the right channel because it is closest acoustically to the right channel mic. However, the left channel mic sees it from a slightly different perspective and will include the reverberation. The right channel mic is also picking up sum and difference information through the room acoustics. As they randomly mix, an out of phase (L minus R) component is introduced, wherein the left channel is slightly out of phase at times, which 'pushes' the R channel speaker output away from center/right and beyond the right channel. When the phase shifts are extreme that width can be increased up to a point. If the phase difference was extreme, it may start to sound like the instrument is behind you -- or in some cases above you depending on how your ears interpret extreme phase shift. There is no concept of height in these types of recordings. None recorded, at least.

So absolutely, a live soundstage can extended beyond L or R channels on playback. The listening room might be able to enhance that in a believable (but not consistent) way, or it might destroy information that the recording contains, skewing the display of the sound stage. That's primarily why my preference is for 'the room to get out of the way' so I can hear what's really on the recording.

--Bill

 

[treitz3]

I am not in total agreement treitz. Some speakers just have squat stages no matter what music you play on them so I'm inclined to believe the speakers must have some contribution. I will plead the fifth on which of these I've heard.

I will agree that it seems the speakers do play some part with the height, I've heard it myself. At least, like you, I would be inclined to believe this to be true just based upon experience. That said, it appears to be more a case of the recording techniques and room interactions then that of the loudspeaker itself. Could it possible that the speakers we heard that offered the illusion of height, better than the other speakers you had mentioned that had squat, was just a result of the recordings auditioned combined with the room interactions and not so much the speakers?

All this time, I have given credit to the loudspeaker producing height and I have since learned otherwise. This forces me to rethink every aspect of what it is I have been observing when it comes to height in a reproduction.

 

[JackD201]

I think we all agree more than we disagree. We're all just looking at things from different perspectives. While I still won't name makes and models, I will say that all of them had their midrange sources low to the ground. Images could be moved higher but in all instances results could only be really called substantial if they were raked back and had them toed so they crossed in front of the listening position. Not surprisingly this often caused problems worse than a diorama like presentation

On the other hand I've heard quite a few shortie speakers image above the tops of their cabinets. I attribute this to better vertical off axis response. Good examples I will name Verity Parsifals come to mind.

 

[Soundproof]

You will still need the smoke and mirrors that occurs at the mixing console in order to play music in your steely-eyed acoustical science designed listening room.

Acoustical science applies during both the recording and playback stages. No reason to think otherwise. My personal taste runs towards live recordings and releases made before they started the chopped-liver approach to recording music. These have believable sound-stages with authentic room-reverb, not the plastered artifical kind that recording engineers believe people can't distinguish from the real.
Listening to these, I'm quite used to walls falling away.

Here are two spotify-tracks that demonstrate the importance of recording technique to what we hear in our listening rooms. The same piece of music, played by different performers, and definitely recorded differently.
One sounds as if the performers are inside a room, and the microphones are registering through an open window (still stereo); the other sounds as if the music is embracing you. And there is verticality to how the sound is perceived.

Here's Barenboim/Zukermann, in an atrocious recording of the Kreutzer. No complaints about the performance, but poorly recorded. Everything is inside the area described by the speakers:
http://open.spotify.com/track/3TdMFhukNobGk6hUfenOF8

Here are Argerich/Repin in the same work - recorded quite differently:
http://open.spotify.com/track/0gQGjZqOhplmv9kL76z3I2

Useful tracks for evaluating what creates a sound stage, and what doesn't. You'll find that in the latter case, the sound seems to emanate from places far outside the extension of the speaker set-up.

 

[bblue]

Mark, as usual, you have a knack for hitting the nail on the head. For someone to say there is no such thing as image height tells me that they've never heard a good high-end speaker or system.

Every recording, every speaker, every cartridge, every component in the room, affect imaging and image height. Some even exaggerate it. Other components make a recording sound like The Lilliputian Symphony Orchestra or Schroeder's piano. On a good recording, you should be able to see in the mind's eye where the singer was relative to the mike. That's esp. true for line source speakers in my experience. And yes, you can not only hear and feel the side walls but the ceiling. It should be made obligatory for everyone who talks about anything in audio to go to HPs to hear what a truly great high-end system can do. Until then, most have no idea what they're talking about.

People do have very active imaginations, and if they believe they're hearing a height element, that's what they hear.

But think about it. A single speaker produces sound forward. The better the design the more absolutely forward it is. Around the crossover frequencies you may find some phase shift, and some crossovers require the individual drivers to be out of absolute phase with one another so they will be in phase during the crossover transition. These characteristics can create an illusion that particular frequencies are shifted one direction or another, and can also interact with the room in a similar fashion. But the important issue is that with a single speaker there is no signal control in a recording that will shift the audio in any direction but straight ahead.

Now, you add a second speaker forming the L and R pair.. Each of those speakers can only fire forward. However, the amplitude and phase shift of the signal, one channel relative to the other, simulates L to R position to varying degrees. THERE IS NO UP AND DOWN. It's strictly lateral apparent motion.

Now, add the effects of crossover performance, absolute phase of drivers and a room randomly inserting its signature in there, to the lateral positional information and you can get some pretty bizarre effects. They'll typically vary significantly from recording to recording and are only playing with your ears. There's nothing real about it, and it's not recorded so you can hear it that way.

Once you learn how those effects and limitations actually sound and hear them for what they really are, what you hear starts making more sense. Yes, some of the 'magic' is gone, but ...

--Bill

 

[MylesBAstor]

People do have very active imaginations, and if they believe they're hearing a height element, that's what they hear.

But think about it. A single speaker produces sound forward. The better the design the more absolutely forward it is. Around the crossover frequencies you may find some phase shift, and some crossovers require the individual drivers to be out of absolute phase with one another so they will be in phase during the crossover transition. These characteristics can create an illusion that particular frequencies are shifted one direction or another, and can also interact with the room in a similar fashion. But the important issue is that with a single speaker there is no signal control in a recording that will shift the audio in any direction but straight ahead.

Now, you add a second speaker forming the L and R pair.. Each of those speakers can only fire forward. However, the amplitude and phase shift of the signal, one channel relative to the other, simulates L to R position to varying degrees. THERE IS NO UP AND DOWN. It's strictly lateral apparent motion.

Now, add the effects of crossover performance, absolute phase of drivers and a room randomly inserting its signature in there, to the lateral positional information and you can get some pretty bizarre effects. They'll typically vary significantly from recording to recording and are only playing with your ears. There's nothing real about it, and it's not recorded so you can hear it that way.

Once you learn how those effects and limitations actually sound and hear them for what they really are, what you hear starts making more sense. Yes, some of the 'magic' is gone, but ...

--Bill

puhleeze....and bumble bees can't fly either.

And sorry that single driver, xoverless speakers or electrostats blow your theory.