Soundstage, what is it exactly?

[Duke]

Near-field listening in a not too small and well-damped room, mostly. But that can be too intimate and dry with some recordings, therefore I sometimes take the liberty to apply some reverb and early reflections, the wet signal passing though the "blow-it-up-to-3D" mechanism mentioned earlier (slight amount of speaker crosstalk cancelling applied on a slightly narrowed stereo width). And I find proper "digital room correction" a must, in almost all situations.

This sounds like a very well thought-out approach with judiciously-applied signal processing as needed.

When you say that you sometimes "apply some reverb and early reflections", is that added to the signal being reproduced through the main speakers, or does it arrive through other speakers?

Does what you're doing change from one recording to the next?

Time - intensity trading, yes, near constant directivity if possible in the most critical range 700-7kHz for pinpoint imaging and wide coverage or sweet area, rather than sweet spot, if you will. This also helps the perception of depth (distance and proximity). However, there's also perception of space in the low frequencies and the perception of what would sound like the diffuse field. For that you really need very wide coverage but the kind that would work with the setup...

Also, I don't want vertical reflections in order to more effectively manipulate direct to reverberant sound ratio. When it comes to side reflections, in terms of energy, the right spectral balance and time of arrival of lateral and contralateral reflections IMO is required both for early and late spatial impressions. So again very, very wide coverage helps if you want to manipulate the side energy, but with the right amount of attenuation of what radiates to the sides.

Thank you. I like the way you address the lateral reflections but still prioritize having a good diffuse field. Setting aside (for now) the bass region -

I use a different approach to the arguably somewhat conflicting requirements of combining a radiation pattern that works well for time-intensity trading with having a good diffuse field, or at least a good approximation thereof. I use "supplemental" speakers or "supporting" speakers to inject some fairly late-onset reflection energy. @youngho started a thread which looked into studies of this approach here:

"Room compensation for loudspeaker reproduction using a supporting source"

I was browsing Soren Bech's recent publications (https://vbn.aau.dk/en/persons/100940/publications/) and ran across this interesting paper "Room Compensation for Loudspeaker Reproduction Using a Supporting Source"...

www.audiosciencereview.com

 

[audiofooled]

arguably somewhat conflicting requirements of combining a radiation pattern that works well for time-intensity trading with having a good diffuse field, or at least a good approximation thereof

Well, the direct sound is the first to get there. Time-intensity trading in itself if implemented correctly should yield results such as this as far as imaging:

Time intensity trading | Auditory Neuroscience

auditoryneuroscience.com

Virtual Acoustic Space | Auditory Neuroscience

auditoryneuroscience.com

Note the precision required on the first arrival. As far as conflicting requirements, you are normally "out of focus" at the listening position, the axis being crossed in front. This is what gives you the advantage of a large "sweet area" as far as imaging. What actually sounds perceptually diffuse (and not just weird) is a matter of a lot of research but I like to think that actually also being slightly out of focus helps, so this is at least one thing in common to deal with conflicting requirements. But you also need a good amount of late arrival energy to be manipulated, also with the right spectral balance.

To see what I mean, here are some impulse responses to highlight the patterns of early and late arrival energy. Note that this is hybrid array combining both waveguides and open baffle (not on the same drivers!), so arguably a very flawed design, and never ending quest, as anything DIY
Also, the setup is not symmetric as far as side boundaries.

L:

R:

L+R:

Note how far in the timeline the energy extends.

Now let's overlay all the graphs:

And zoom in to show "out of focus" and misalignment (hopefully the right decorrelation) on some of the late arrival energy:

Note that L+R (red) also sums at 6 dB louder in the direct field.

To quote JJ:

"Not so much loudness, but by setting it to a near-field (say 2 meter) focus, you can create an amplified distance sensation, so if you're 4 meters away it sounds like you're 100% in the diffuse field, and at 2 meters, you're fully direct. It's a great effect for some things, you can listen to the same track as you walk toward the speaker arrays, the stage zooms up to meet you very effectively."

Have a nice day

 

[KSTR]

When you say that you sometimes "apply some reverb and early reflections", is that added to the signal being reproduced through the main speakers, or does it arrive through other speakers?

Hi,
through the main speakers for convenience of processing, though I admit the effect can be quite a bit better when you have extra "ambience" speakers for this and extra channels available on the DAC.

Does what you're doing change from one recording to the next?

Yes, but I'm not dogmatic about it. Basically I have a few presets and/or play live with the parameters. The dryer the recording and lower the listening volume, the more artificial envelopment I typically add.

 

[tmuikku]

I also completely agree with @olieb when he points out even in the best seat in a classical concert you cannot pinpoint the exact location of every instrument (the goal in classical is always that "the whole is greater than the sum of its parts". Putting razor sharp separation in that -if even possible- could be distracting from the "performance". But of course we want the clear overall location info that classical is most often arranged into.

Localization is goal, only best seats have it, at least that's what I've picked up from papers like this https://www.audiosciencereview.com/forum/index.php?attachments/p35-pdf.327131/

Concert hall acoustics assessment with individually elicited attributes - PubMed

Concert hall acoustics was evaluated with a descriptive sensory analysis method by employing an individual vocabulary development technique. The goal was to obtain sensory profiles of three concert halls by eliciting perceptual attributes for evaluation and comparison of the halls. The stimuli...

pubmed.ncbi.nlm.nih.gov

 

[Geert]

but peeing through a window into the recorded space.

I thought a colleague sound engineer would be more respectful.

 

[AJM1981]

It is mainly an illusion created by the recording, the room, the properties of the loudspeaker and the properties of an amp in damping factors and roll off etc. I have owned quite some amps and read a lot of reviews. I get the idea that in the hi-fi world of the past (not that much into modern amps anymore) going up the line usually meant that an end user should experience more "grandeur" and a bigger sound stage illusion would be that to an amp as what length would be to a car. Only power and buttons would not make a sales difference.

I also noticed that a much of the "soundstage magic" lies in really focused listening to a new setup. Something about getting used to something and switching more from being focused to background listening at a certain point.

In producing there are also stereo expanders, not that it is anywhere near, but when applying sets of properties to a minor degree some treats work really well. Now there are other factors in the mix when it comes to amps. But since hi-fi was built for consumers, a tiny bit of an expansion illusion will do loads to perception.

 

[tmuikku]

My hypothesis: bought new amp, you lean forward to hear the difference and voila, difference there is. It might not be the amplifier, but the forward lean. You got physically closer to speakers, all early reflection delays got bit later, direct sound bit louder and so on, and your auditory system does not consider the sound as noise anymore and there is focus and clarity and all.

 

[Anton S]

Soundstage is a term whose meaning has shifted significantly over time, which often leads to people talking past each other without realizing it.

In the original, “old school” sense of stereo (1950s–1960s), soundstage referred specifically to the phantom image and sound scene created between the two loudspeakers. This was the core promise of stereo: stable, convincing lateral placement of instruments and voices along the line connecting the left and right speakers, achieved mainly through amplitude panning and basic phase/ITD cues. That is what classic stereo was engineered to do.

As audio technology, recording techniques, and listening environments evolved, the term soundstage expanded in audiophile circles. It came to include the ability to create illusions of sound outside or beyond the physical speakers — wider than the speaker span, with added depth layering, and sometimes even vague height or “air.” A recording or system praised for “great soundstage” today is often valued more for this extended, spacious presentation than for a tightly focused image strictly between the speakers. As a result, a well-engineered classic stereo recording that excels at precise internal imaging might be rated lower by modern listeners than one engineered (or played back) to push sounds outward. Think 8D remastered.

This evolution has created real confusion. The term is now frequently mixed up with spatial audio — a more recent concept involving fuller 3D reproduction through multi-channel formats (like Dolby Atmos), advanced binaural processing, or room correction. What began as a straightforward description of two-channel stereo capability has become broader and more subjective, leaving many (including long-time listeners) unsure what exactly someone means when they say “soundstage

ST

Thanks, @STC. In my mind, that "old-school" definition is still applicable when I'm describing what I hear, i.e. the L-R positioning of the performers across a virtual stage. To help keep things straight in my own mind, I've always used the term "stage depth" when describing my perception of front-back placement within the sound field. As for "imaging," I think of it as experiencing the audio equivalent seeing a sculpture, rather than viewing a painting or photo of that same sculpture. For example, I can still recall hearing monaural recordings on single-speaker systems back in the early sixties that were able to reproduce what I thought was great imaging, in that they recreated - for me - the illusion of hearing real, tangible instruments.

With respect to multichannel systems, I think the best implementations help to recreate an impression of the "acoustic space" of a live venue - regardless of whether that space was captured during recording or fabricated in the studio - without calling undue attention to the additional speakers as discrete sound sources. While I readily admit that good 1-, 2-, and 3-channel systems are also able to reproduce that sense of acoustic space to a certain extent, I think that well done multichannel systems are able to do it more convincingly - for me, anyway. I further believe that well executed multichannel systems significantly enlarge the listening "sweet spot" and help eliminate "head in a vise" listening. Those are, for me, the best qualities that multichannel systems bring to the table from a music listening perspective.

That's just the way I think of and describe my listening experiences, so no flame throwers, please.

 

[STC]

Thanks, @STC. In my mind, that "old-school" definition is still applicable when I'm describing what I hear, i.e. the L-R positioning of the performers across a virtual stage. To help keep things straight in my own mind, I've always used the term "stage depth" when describing my perception of front-back placement within the sound field. As for "imaging," I think of it as experiencing the audio equivalent seeing a sculpture, rather than viewing a painting or photo of that same sculpture. For example, I can still recall hearing monaural recordings on single-speaker systems back in the early sixties that were able to reproduce what I thought was great imaging, in that they recreated - for me - the illusion of hearing real, tangible instruments.

With respect to multichannel systems, I think the best implementations help to recreate an impression of the "acoustic space" of a live venue - regardless of whether that space was captured during recording or fabricated in the studio - without calling undue attention to the additional speakers as discrete sound sources. While I readily admit that good 1-, 2-, and 3-channel systems are also able to reproduce that sense of acoustic space to a certain extent, I think that well done multichannel systems are able to do it more convincingly - for me, anyway. I further believe that well executed multichannel systems significantly enlarge the listening "sweet spot" and help eliminate "head in a vise" listening. Those are, for me, the best qualities that multichannel systems bring to the table from a music listening perspective.

That's just the way I think of and describe my listening experiences, so no flame throwers, please.

Anton,

Sorry for the late reply — I didn’t receive any notification for your post.

Thanks for the clear historical overview and for sharing your personal way of distinguishing “soundstage” (L-R) from stage depth and vertical extension. That’s a helpful framework. A multichannel when properly done will outperform stereo. But all good music that I grew up with were in stereo and that’s was my final goal to bring the best out of them.

Appreciate your definition.

ST