What exactly is "imaging" ?

[George J]

When I first had the chance to listen to stereo replay in 1973, I did not like it. As an eleven year old I was already a veteran concert goer [for my age] having been to three - in Worcester Cathedral, The Malvern Festival Theatre and Malvern Priory - and stereo sounded nothing like real to me ...
I have owned stereo replay since, but for about the last ten years have been mono for serious listening. Mono may not be like real either, but it can be one heck of a lot closer than stereo ...

Imaging and soundstage are known to be a artificial illusions that attempt and fail to improve on mono as a musical replay method.

I am tempted to say that once the replay and recording industries realised the extra profit to be made from selling virtually double mono outfits, they enthusiastically invested in a money making a superfluous system. Certainly is not as accurate or musically rewarding as mono replay.

AD Blumlein was the man at EMI who made the first practical stereo system in 1934. In the process made some music recordings among other experiments during development before combining it with cinematic film recording. His idea was to make the cinema more realistic so that voices followed the characters as they moved from side to side of the projected picture. He was ahead of his time of course. He thought the system had no real application when recording music ... He was right.

Still nearly sixty years on since stereo became a consumer medium, it clearly is still the subject of [fruitless] debate which need never have happened if the standard had remained with the musically lucid and easily enjoyed mono that preceded it.

Just a tiny observation from someone who jumped the stereo bandwagon years ago. George

 

[Nagraboy]

That’s a bit over the top George. Unlike mono, at least stereo has a left-right dimension like the real world does. Ok, it’s not perfectly accurate - the coughs from the other concertgoers are all in front of you instead of behind you for a start. I enjoy mono too, but it’s not more spacially realistic than stereo. Classical SACDs in 5 channel surround is the best I’ve heard.

 

[adamdea]

I can’t believe no one has mentioned that all important element, colour. All this narrow minded non-chromaesthesia makes me wonder if any of you people know how to set up a stereo.

 

[George J]

Timbre, or colour, is the life blood of musical expression ... from a silky gentle sound to a hard, nervous, rhythmic tone ... after pitch and rhythm, colour is equal with dynamic and agogic in the expressive armoury.

Mono does this even better than stereo.

ATB from George

 

[adamdea]

When I first had the chance to listen to stereo replay in 1973, I did not like it. As an eleven year old I was already a veteran concert goer [for my age] having been to three - in Worcester Cathedral, The Malvern Festival Theatre and Malvern Priory - and stereo sounded nothing like real to me ...
I have owned stereo replay since, but for about the last ten years have been mono for serious listening. Mono may not be like real either, but it can be one heck of a lot closer than stereo ...

Imaging and soundstage are known to be a artificial illusions that attempt and fail to improve on mono as a musical replay method.

I am tempted to say that once the replay and recording industries realised the extra profit to be made from selling virtually double mono outfits, they enthusiastically invested in a money making a superfluous system. Certainly is not as accurate or musically rewarding as mono replay.

Not sure I would go quite that far, George but I have been spending a lot of time recently listening to the 1952 Furtwangler and the 1936 Reiner Tristans and wondering whether I need anything else.

 

[George J]

Dear Alamdea,

The trouble for mono is that commercial mono recordings finished fifty years ago.

I imagine if stereo had never happened, just imagine how fine mono would be today if it were still the main medium.

Actually you don't have to imagine because the BBC broadcast VHF/FM in mono with a stereo plus and minus signal for channel separation. The mono is often better than than any commercial recording this way. I just listened to Brahms Four from the Proms in a performance I would have been grateful to attend in person.

All the colour, all the dynamics, all the sense of an orchestra on top form playing so expressively. I can't ask for more. My radio and my speaker are both sixty-four years old and I cannot imagine they would be bested in stereo by ANY system as it went .. at least on musical terms.

I don't consider lift and separate - terrible Playtex brassiere advert from fifty years ago, and akin to stereo in effect - would have brought any more musical enjoyment to the table in the comfort of my own home ...

Best wishes from George

 

[adamdea]

Dear Alamdea,

The trouble for mono is that commercial mono recordings finished fifty years ago.

I imagine if stereo had never happened, just imagine how fine mono would be today if it were still the main medium.

Actually you don't have to imagine because the BBC broadcast VHF/FM in mono with a stereo plus and minus signal for channel separation. The mono is often better than than any commercial recording this way. I just listened to Brahms Four from the Proms in a performance I would have been grateful to attend in person.

All the colour, all the dynamics, all the sense of an orchestra on top form playing so expressively. I can't ask for more. My radio and my speaker are both sixty-four years old and I cannot imagine they would be bested in stereo by ANY system as it went .. at least on musical terms.

Best wishes from George

I should have been there, George, and on Friday to the first night, but I got pinged just as I was about to set off on Friday.
It did sound pretty good on R3.

 

[tuga]

Err, you! You proudly proclaimed upthread that all mic information lines up in a flat 2d row between your speakers “like hanging on a washing line”. No compression of recorded reflections and other spacial cues, no comprehension of how our hearing processes and decodes that information. Just ‘burp up a book’ fundamentalism. That is how it comes across anyway.

PS If you were talking about totally dry test tones from a signal generator, or sources recorded in an anechoic chamber you would be absolutely correct, but that isn’t music, it just isn’t how stuff is recorded or post-processed. In reality there is much more going on.

Weren't we discussing imaging?

 

[tuga]

The Naxos recording of the Missa Criolla has a massively deep soundstage. Cavernous. If your system doesn't recreate that, regardless of 'transparency' and all that guff, it's not hifi.

It's given by the room cues (it was probably recorded in a church), not by stereo.

 

[davidsrsb]

I can’t usually tell where the kick-drum is, and that is something I hope to feel rather than hear. Depends on the recording.

When mixing was done for LP play, kick drum was always made mono centre to avoid the needle jumping out of the groove. Simple limitations of the stereo system.

 

[darrenyeats]

It's given by the room cues (it was probably recorded in a church), not by stereo.

We're talking at cross-purposes then. Room cues (possibly a vague umbrella term that should be unpacked) are among the mechanisms I would see as enabling stereo to convey height.

If a mechanism even works in mono, what about it? You seemed to be saying height illusion couldn't be conveyed via stereo, and now seemingly the opposite, so now I'm confused.

 

[chartz]

In French, we use stereo image, or stereo effect for the holographic ability and soundstage as a generic term for how real the sound appears in front of the listener. Everyone agrees on what they mean!

One of the best holographic sounds I’ve heard so far was a live FM broadcast through ESL63’s, in 1981. Typical ORTF microphone pair, pure analogue sound – magical.

 

[evand]

I don't know how to achieve it, increase it and what factors contribute to good imaging? Is it even worth pursuing?

Unreservedly worth pursuing.

Assuming your listening space isn't an acoustic nightmare achieving it is for the most part a question of symmetry, distance between speakers and speaker toe-in (the latter 2 requiring experimentation to find the optimal soundstage based on the speakers in question. Too much toe-in and the stereo image becomes small. Too much toe-in and it breaks up.

By symmetry I mean symmetry of speakers to listening position. Think of it as an isosceles triangle. Horizontal symmetry of speaker is also important - if you rest a laser line pointer on the speakers the horizontal line of each against the wall behind your listening position should be at same height. Enter spikes to adjust for uneven flooring.

Get it right and the speakers disappear as a point source.

 

[DimitryZ]

Dear Alamdea,

The trouble for mono is that commercial mono recordings finished fifty years ago.

I imagine if stereo had never happened, just imagine how fine mono would be today if it were still the main medium.

Actually you don't have to imagine because the BBC broadcast VHF/FM in mono with a stereo plus and minus signal for channel separation. The mono is often better than than any commercial recording this way. I just listened to Brahms Four from the Proms in a performance I would have been grateful to attend in person.

All the colour, all the dynamics, all the sense of an orchestra on top form playing so expressively. I can't ask for more. My radio and my speaker are both sixty-four years old and I cannot imagine they would be bested in stereo by ANY system as it went .. at least on musical terms.

I don't consider lift and separate - terrible Playtex brassiere advert from fifty years ago, and akin to stereo in effect - would have brought any more musical enjoyment to the table in the comfort of my own home ...

Best wishes from George

I will give mono another try, George.

Certainly FM radio is more solid and less prone to interference in mono.

 

[tuga]

We're talking at cross-purposes then. Room cues (possibly a vague umbrella term that should be unpacked) are among the mechanisms I would see as enabling stereo to convey height.

If a mechanism even works in mono, what about it? You seemed to be saying height illusion couldn't be conveyed via stereo, and now seemingly the opposite, so now I'm confused.

I haven't mentioned height in this particular example you gave, only ambience (a sense of space). The meaning of the term as described by Stereophile's glossary may help:

ambience The aurally perceived impression of an acoustical space, such as the performing hall in which a recording was made.

Have you seen the dispersion (horizontal and vertical) characteristics of a loudspeaker? Tell me by which mechanism it would possible to reproduce height? (don't, because it isn't)

 

[tuga]

In French, we use stereo image, or stereo effect for the holographic ability and soundstage as a generic term for how real the sound appears in front of the listener. Everyone agrees on what they mean!

One of the best holographic sounds I’ve heard so far was a live FM broadcast through ESL63’s, in 1981. Typical ORTF microphone pair, pure analogue sound – magical.

You (and anyone else who can read French) may enjoy this presentation by J-M Le Cléac'h:

www.melaudia.net/zdoc/distorsion_de_phase.pdf

 

[chartz]

Thanks fot that. Very precise and documented article from a respected man in French hi-fi circles.
There are also many articles by Jean Hiraga on the subject. I think I've read them all (that's a 40-year period I'm talking about!).

 

[adamdea]

We're talking at cross-purposes then. Room cues (possibly a vague umbrella term that should be unpacked) are among the mechanisms I would see as enabling stereo to convey height.

If a mechanism even works in mono, what about it? You seemed to be saying height illusion couldn't be conveyed via stereo, and now seemingly the opposite, so now I'm confused.

Darren you clearly are talking at cross purposes because it depends what you mean by "convey" "height" and "illusion". You sem to be talkng about the quesiton of whether people get some general sense of height, Tuga and I are talking about whether height information can be encoded.

It is likely that listeners will get a general sense of height in some recordings (although it's worth bearig in mind that some people will get a sense of "blue" too). However that is not the same as saying that a recording can distinctly encode height information like it can left/right information and encode some distance information. It therefore cannot convey that specfic information.

As I'm sure you know in stereo recording the reflection of sound off the ceiling is encoded in the same way as the reflection off the front and back wall- you just get "space", not distinct back front ceiling refections (without some form of dummy head or artifical encoding). Given frontal direction with stereo (the sound really is coming from the front) your brain then makes a few guesses which may vary from person to person. Distinct height information is not really encoded but the brain is a wonderful thing. Sounds like a church, probably has a high ceiling, some of this sound must be bouncing off that. (mono can do that too, but the left right thing can give you a bit more left right stuff which is going to help make the sense of space more concrete.)

That's with room cues. Now how is stereo going to encode the difference between a violin right in front of you and one at 20 degrees above the azimouth? And how come, given the way they are miked, all those live classical recordings don't seem to have an orchestra down below the speakers?

It's all pretty obvious once one gets how the hearing works and how stereo work. But working back from "I get a sense of height" is confusing. Of course an illusion will involve a sense of height and indeed size, or it wouldn't be an illusion (your brain is not going to be tricked into thinking it exists in a two dimensional space).

 

[davidsrsb]

One of the best holographic sounds I’ve heard so far was a live FM broadcast through ESL63’s, in 1981. Typical ORTF microphone pair, pure analogue sound – magical.

One of the rare occasions when reflection height cues were actually recorded. For the other 99.9% it just isn't

 

[Sue Pertwee-Tyr]

Darren you clearly are talking at cross purposes because it depends what you mean by "convey" "height" and "illusion". You sem to be talkng abiut the quesiton of whether peole get some gernal sens eof height, Tuga and I are talking about whether height informaiton can be encoded.
<snip>

It's all pretty obvious once one gets how the hearing works and how stereo work. But working back from "I get a sense of height" is confusing. Of course an illusion will involve a sense of height and indeed size, or it wouldn't be an illusion (your brain is not going to be tricked into thinking it exists in a two dimensional space).

Will due respect to Tuga, if that's his argument, he isn't making it clear in his insistent reliance on the loudspeaker's dispersion characteristics, for his view that it simply isn't possible. If anybody is talking at cross-purposes, I'm not sure it is those of us who observe that we can perceive height in an image, just as we can perceive depth and width. They are part of the illusion, whether they are specifically encoded as such in the signal is somewhat moot. One of the basic requirements for media is that they enable the 'willing suspension of disbelief' - ie I know there isn't a symphony orchestra in my living room, but I'm over it. I'm content for my brain to do what it does with what it receives, and perceive the result.