Should a stereo soundstage be 3D or 2D?

Please keep in mind that this is speaker + room dependent. 

The better the room is treated, the more the imaging will be allowed to develop.  I think height is more realistic with line sources and panels.

Best,

E

If speakers aren't time aligned, do we get 4D? 

Frontal 3D.It can depending on what you are listening to at times feel surrounded. 

I have always assumed it meant left-right and then some amount of depth, so I took that to be 3 dimensions.  Images not just between the speakers (the left-right-center), but also behind.

3d - depth of stage

@saintsaens_op61
It should be 3D, ie. width, height, and depth.
If the system is properly set up, that is, and the recording is good.

e.g. On your favourite St Saens opus 61 (3rd violin concerto) and with dipole speakers, the violinist is in the room while the orchestra is well behind him and beyond (Vengerov, Philarmonia-Pappano, or Shaham, NYP-Sinopoli), outside the room. Regards

The best way to test your system, for accurate (faithful to whatever’s on your media, at least) sound stage reproduction: https://www.audiocheck.net/audiotests_ledr.php                             Also available, on the following Chesky CD, along with a number of other tests(ie: stage depth, Wood Effect/reverse polarity, etc): https://www.amazon.com/Chesky-Records-Sampler-Audiophile-Compact/dp/B000003GF3    (No doubt, that CD could be found for less, elsewhere)                                        More info, regarding the LEDR test: https://www.stereophile.com/features/772/index.html

+1 what @gregm said.

With the right speakers, room acoustics, components, and let’s NOT forget cables - a good recording will immerse you in the performance and the size of the venue and its related acoustics will will become very apparent.

I have a recording of a single Harmonica being played in a church, with pipe organ in the back ground. The resulting sound "transports you" to the venue complete with reverberations and echoes off the walls and ceilings - it is very 3D.

The venue acoustics start to become even more apparent with higher resolving cables - i.e. IC’s, Speaker and power cables.

Most components and many speakers today have the capability of reproducing those subtle acoustics, but very often it is the cables that are not capable of allowing the extremely delicate signals associated with venue acoustics to be adequately transferred between components and speakers.

Also, much of the "dimension" of a recording can be lost due to noise in the various cables - which impacts the component’s ability to faithfully reproduce L/R channels as recorded, impacting image and therefore the sense of "space"

YES - I am a cable believer :-)

Hope that helps - Steve

I'm not sure if stereophonic reproduction was ever conceived or designed to provide height cues, but well-set-up, good systems can give some, albeit not as pinpoint or extreme as breadth and depth.  Some speakers are reputed to "do" height better than others; I've had a hard time hearing that.  Find a recording of a flamenco dancer stamping her feet (zapateo) and clicking the castanets high over her head, and report back!!

@twoleftears - I think you are correct, in that the first two channel recordings were by comparison to later recordings simply using the two channels to achieve instrument placement in a single dimension across the image. Then sound engineers discovered instruments could be "located’ in two dimensions, i.e. front to back also.

then some artists, using a technique called phasing, are able to fool us into thinking the sound is behind us.

However, based on my own observations, it would appear that recording two channels very accurately captures the venue acoustics, i.e. those little reverberations and echoes off the ceilings and walls, which seems to "fool" our senses into hearing height. Perhaps height is not the right term, maybe it’s more a "sense of space", in particular, a large space..

So if we can reproduce the recorded signal "accurately" we should be able to recreate the recorded image, complete with its sense of space - yes?.

I’ve only recently become aware of this "effect", thanks to the cables I now have in my system. They are DIY and so over the course of their development, I became increasingly aware of how the details of the venue acoustics improved with each version of the cables and how those reverberations and echoes played a role in recreating the image with amazing reality, i.e. sense of space.

With the advancement in recording technology and the also audio equipment, I believe three dimensional sound using two channels is now a reality. You just need the right gear.

I don’t know if any system is capable of achieving your "Flamenco Challenge", mainly because audio enthusiasts spend a lot of time trying to get rid of reflected sound adn perhaps we need to utilize an element of that. But as we learn more about this hobby I can see a day when your challenge will be a achieved.

If you happen to have the name of such a track - I would be interested hear it on my system, which I believe has an innate sense of space.

Regards - Steve

Thank for the helpful responses, everyone. @williewonka , I like your explanation of how the 3D soundstage provides a “sense of space”. That makes more sense than the speakers providing definite vertical separation. 

I have never been to a live performance (orchestra, acoustic etc) where I perceived front to back cues.

I imagine that any front to back cues that may exist in our systems and recordings has more to do how the recording session was mic'd.  But it is my opinion that is not how live music sounds.

@rodman99999 thanks for the Audio Check link! Just now, I did the LEDR test with my headphones, and I could hear the test tone move up in an arc, in addition to left to right. 

@jderimig

That is very true, thus the paradox of live vs recorded music. We are so far from replicating a live performance still, I think the only way we can ’think’ of doing so is with these spacial cues. And I am just as guilty of that. I want and need depth (sound coming from behind and in front of the speakers), height, width, etc. as for most of us it creates an illusion of space, a room, a ’soundstage’. When a recording wasn’t mic’d or engineered to offer that, it displeases me.

As you say, rarely in a live performance do those spacial cues exist. But the difference is that ’we are there’, we can perceive the space and separation with our eyes, whereas in reproduced audio, we only have our ears.

It is odd, but I think most of us strive for that ’3D’ imaging during playback.

Interesting, when I watch the Berlin Philharmonic live on my TV and system in 5 channel HT mode, I’m not as critical about those things (stereo imaging) as I’m also watching the performance, and as the sound is all around me, also not realistic. But none-the-less, enjoyable. Funny how I cannot listen to only music in that mode.

Perhaps the reason why some live concerts appear two dimensional is because of the two really large "walls" of speakers each side of the stage.

Even orchestral concerts are mic'd these days - but if you get in the right concert hall, you will definitely hear depth and height(i.e. sense of space) from a live performance.

The live recordings made in churches and smaller halls tend to exhibit more front to back and a greater sense of space. I have several tracks that excel in making you believe you are right there in the midst of things when played on a two channel system.

One of the better rock recordings that also provide the grandeur of the hall it was "supposed" to have been recorded in is "The Best of Supertramp". A fine example of studio sound engineering at its very best Dire straits also has some great live recording.

Regards - Steve

Take a look at HAF (Home Audio Fidelity) website. Previously mentioned Townshend Seismic Podiums. Synergistic Research Atmosphere or Carbon FEQ + HFT's.