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Sound stage - imaging question

B

busb

Mine's a pint of beer please
Firstly, are they the same thing?
As for imaging in general, I presume it's nothing to do with stereo separation & that mono music can give good imaging.
Further thoughts are what part of any system contributes the most to it - speakers? And finally, is it related to something like good time-domain coherence (whatever that is).
 
1) channel equality: both speakers must have the same frequency response (amplitude and phase), see the exact-same acoustic environment, and be the exact-same distance from the listener

2) tonal neutrality, both on-axis and off-axis: contrary to popular belief, imaging is a largely function of frequency response

3) absence of resonances, heavy intermodulation distortion, and other spurious sounds that may mask the decay and ambience in the recording
 
Mono can give good 'imaging' in the sense of allowing you to sense the relative distances from you of instruments and the resulting 'hall ambience' in which they reside. Stereo can then add the ability to hear the direction from which each instrument comes, etc.

The basic requirements for both are as Werner says. Main difference is that with mono the image will be central and any differences between the speakers or asymmetric room response, etc, will shift or smear that laterally.

For me, good imaging is vital as most of what I listen to is classical music from some form of venue or decent hall. Even with some old mono recordings you can get a good sense of the hall/room/studio the performers were in, etc.

It may be surprising when first encountered by some early stereo can have an excellent image because they only had a few mics and channels so had to take care about placement. Later there was a tendency to spray mics around and try to 'sort it out in the mix'. That can be fine, but can also turn out to be a mistake. :)

So, of course, this all also depends on the people doing the *recording* making a good job of it.
 
For me, soundstaging is a presentational issue involving depth and width; does it fill the room from side wall to side wall?

Imaging is being able to pick out salient instruments/voices in different parts of the soundstage.

Stereo, of course; no idea about mono.

My experience so far is that stand-mounts give good imaging but are poor in soundstaging. Bigger floor-mounters can be good at both, depending on design. Larger electrostatics major on soundstaging and imaging.

Valved amplification seems to be inherently better than s/s. This is all very simplistic and with caveats, but these are my findings over half a century.
 
I thought phase had a lot to do with imaging too - I remember a demo when I was a student where sounds were played in a dark room and we had to identify the source - to us they sounded like sounds cam from left, right, and centre like any good stereo.
When the lights came on there was only a single speaker and we were told it's done by phase changes (not sure exactly what they meant though)
 
Jim Audiomisc said:
Mono can give good 'imaging' in the sense of allowing you to sense the relative distances from you of instruments and the resulting 'hall ambience' in which they reside. Stereo can then add the ability to hear the direction from which each instrument comes, etc.
....
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It would be nice if some music producers took more care with their stereo imaging - I have some albums where the band and lead vocal seem to come entirely from the left side. It sounds 'wrong' to me (or maybe it's my hearing)
 
zippy said:
It would be nice if some music producers took more care with their stereo imaging - I have some albums where the band and lead vocal seem to come entirely from the left side. It sounds 'wrong' to me (or maybe it's my hearing)
Click to expand...

An advantage of many old amplifier designs is that they have a mono button and a balance control. This helps people check that their setup is reasonably balanced even if they only have stereo music to play.

And FWIW I often find I'm adjusting the balance slightly from one LP/CD/etc to another.

Shame that so many modern amp designs omit such controls.
 
I would say that

imaging has to do with the speakers' ability to create an illusion of sound sources in the room

whilst

the soundstage effect has to do with a sense of space which results from acoustic cues of the space where the recording took place, and is a property of the recording


A setup using adequately positioned mics can capture the ambience of live acoustic, unamplified music recorded in a venue with a natural resonant behaviour and a good system will be able to reasonably recreate this.

On the other hand, studio recordings are generally close-mic'ed in the semi-anechoic nature of the rooms and booths which means that the ambience will have to be created in the mixing console during post-processing because it doesn't exist in real life.
The sense of space in these recordings can sometimes sound dry and uninspiring and will benefit from a bit of a boost, which can be achieved by adding a bit of reverb (using valve amplifiers that produce high levels of low even order harmonic distortion) or creating ghost images in the room (by placing the speakers close to the side-walls with no toe-in).

R
 
Mike Reed said:
For me, soundstaging is a presentational issue involving depth and width; does it fill the room from side wall to side wall?

Imaging is being able to pick out salient instruments/voices in different parts of the soundstage.
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Interesting, Mike - I've never really separated out the two. This thread was partly prompted by "The magic of small Speakers" thread where the consensus seemed to be that small speakers "imaged" better than larger ones. I don't entirely agree but want to get a handle on what attributes give excellent imaging.
 
I don't really understand "sound-stage". If it's about the ambience, then most of that will come from the recording. A particularly lively room will add to that. If it's about the width, depth and height of the sound, then it'll have more to do with the dispersion characteristics of the loudspeakers, but electronics can alter that too. Sound-stage width is easily adjusted with toe-angle, which also affects depth perception, but not so much height.

Imaging is about locating each instrument or voice on the "sound-stage". Caring about such details is akin to watching a movie in 3D and marvelling at the effects, notwithstanding whether the movie is good or not.

Each to their own, I guess.
 
busb said:
Interesting, Mike - I've never really separated out the two. This thread was partly prompted by "The magic of small Speakers" thread where the consensus seemed to be that small speakers "imaged" better than larger ones. I don't entirely agree but want to get a handle on what attributes give excellent imaging.
Click to expand...

I would say that side-wall reflections resulting from the use of wide-dispersion speakers (i.e. most narrow baffle designs) do favour soundstage but not imaging.
My guess is that imaging would be best in an anechoic chamber.

R
 
I have found that strong image solidity and reproduction of acoustic space has a lot to do with the way high frequencies are reproduced.
 
''Phase-response!
One of the things I found out was the underrated importance of phase response. Anomalies in phase respons alters everything in a speaker and makes depth , imaging and separation blurry , unfocused and simply inaccurate. When studying how phaseanomolies affect our brain and how we interpret the signals, the importance of this gets even clearer.

The phase anomaly will cause your ears to interpret the signals coming more from the side of the speakers instead of providing you with a steady and focused phantom center in that particular frequency range. Think of it like listening to pseudo stereo in layers of frequency bands. This is very confusing for the brain and will cause ear fatigue and blurr the entire image and separation of the individual tracks. Needless to say this will make our work much harder to perform.
''
https://www.gearslutz.com/board/high-end/949764-amphion-beautiful-66.html

phase response is the number 1 reason for a speaker to image spectacularly or not.

the best holographic imaging ive ever heard is from my previous speakers, the Amphion one18 that I kept for 2 years. I have right now the kef ls50, scm7, shl5+, p3esr: none come close to the amphion imaging. Tannoy for some reason is very impressive imaging wise, but cannot touch amphion either. im pretty sure genelec 8351 or kii three is similar in terms of imaging
 
Ayya Khema said:
The phase anomaly will cause your ears to interpret the signals coming more from the side of the speakers instead of providing you with a steady and focused phantom center in that particular frequency range.
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I used to have an Omnisonix 801 imager back in the 80s. It must have tampered with the phase to make the sonic image taller, wider and deeper. Shame it also screwed the music.

On a related note, some recordings deliberately synthesise 3D holography with phase trickery. I can hear all sorts of 3D effects on Roger Water's Amused to Death album, for example. My loudspeakers must be pretty ace at imaging.
 
Ayya Khema said:
''Phase-response!
One of the things I found out was the underrated importance of phase response. Anomalies in phase respons alters everything in a speaker and makes ...
Click to expand...


A wide-spread fallacy.

Inter-channel differences in phase, yes, these matter. But these fall entirely under my item 1) above. A correctly-setup and non-defective system should not have much inter-channel phase difference.

Phase response itself, i.e. the function of phase versus frequency, can be buggered up totally (within reasonable bounds of course), while not affecting imaging.

However, what might give this notion is that in a minimum phase system, phase and magnitude response are linked, so playing with phase also plays with the magnitude response, and this might well affect front-to-back imaging.
 
zippy said:
Not just me who does that then !
Click to expand...
Hi Zippy,

Jim's answer to your post also contained a subtle comment which correctly or incorrectly resonated with myself. I recently found myself using my balance control on some recordings to make vocal image central; this required a adjustment of just 1db to 2db. It turns out it was my room which was the cause. I had recently placed my record rack next to one of the speakers. This was causing certain frequencies to be boosted. The effect in my case was more apparent with male than female vocals.

Do you per chance have an even slightly imperfect symmetry around your speakers and their 1st reflection points?
 
I have an irregularly shaped room, but the balance control of my Naim 552 stayed in the same position for years on all 4 sources. My current valved pre. doesn't have a balance control, when I probably could use one on the second m/c phono stage. However, I suspect a valve is a bit down, so not really a proper balance problem.

Once upon a time all pre's and integrateds would have a plethora of tone, balance and other adjustment controls, but things nowadays (at the higher end at least) are rather hairshirt; in pursuit of s.q., possibly?
 
Mike Reed said:
Once upon a time all pre's and integrateds would have a plethora of tone, balance and other adjustment controls, but things nowadays (at the higher end at least) are rather hairshirt; in pursuit of s.q., possibly?
Click to expand...

Making *good* tone controls is difficult. If only because both the components and the control pot have to be tightly specced so the channels get adjusted in a close-matched way.

Thus a manufacturer can save a lot of effort by simply omitting them. This also means they can opt out of deciding what tone control shapes, etc, should be used.

However FWIW I always have some stage in the system that lets me tweak tonal balance and channel balance, and gives me a mono switch. In later years I've tended to do this via using a Quad 34 which I modify to suit my situation and preferences.

I think it is a shame that no-one seems now to sell anything akin to the old 'Cello' control. I guess this has been overtaken by people using DSP instead. But I have an old-fashioned preference for an accurate set of analogue controls. :)
 
clivem2 said:
Hi Zippy,

Jim's answer to your post also contained a subtle comment which correctly or incorrectly resonated with myself. I recently found myself using my balance control on some recordings to make vocal image central; this required a adjustment of just 1db to 2db. It turns out it was my room which was the cause. I had recently placed my record rack next to one of the speakers. This was causing certain frequencies to be boosted. The effect in my case was more apparent with male than female vocals.

Do you per chance have an even slightly imperfect symmetry around your speakers and their 1st reflection points?
Click to expand...

The symmetry is actually highly imperfect due to unmoveable furniture, and the left side of the room is absorbtive (armchairs) with the right side highly reflective (Stone fireplace).
I also have marginally different hearing in each ear (but so do most of us).
That may all account for some of the observations, but the left hand bias I mentioned is only on some albums, not all.
 
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