Not much talk on-topic in the thread at this point. I’m more than happy to jump track to interesting off topic tangents.
Any playback system outside of a high-order ambisonic or WFS system is going to distort the location of sound sources compared to what is heard live to some extent, it’s just a question of how and if the distortions are acceptable or not.
I’m of the mindset that it is essentially impossible to reproduce the exact event, and trying to do so is interesting only as an intellectual goal, not an artistic or musically enjoyable one. I have no qualms about setting up my recording rig or adjusting things later to optimize the recording for how it will be played back, or to ‘fix’ problems with the sound at the live event. At one level that simply means editing out obnoxious noises, rumble, pops, et cetera; correcting timbre with EQ, and choosing microphones and setups that sound closer to what I consider ‘good’. Leaving in the hiccups would be more accurate to what was heard there, it’s a judgment call and I aim for better than live in the ways it can be, understanding that some things will always be better live. Usually the goal is one of transparency and striving for the platonic ideal of what I think it should sound like, often an improvement on the live sound I heard at the recording position in some ways.
What is important in a mono recording? With mono there is just one channel so in geometric terms the recording is ‘zero dimensional’ like a point. What is important in a mono recording is overall level, timbre, instrument balance, and the direct/reverberant ratio. There is no left/right imaging, although depth can be implied by differences of timbre, level and reverberence.
Stereo doesn’t make any of those core things less important, it expands things by distributing the sound sources along the line between the speakers. It’s a line between two points, so it’s geometrically one-dimensional. Overall level, timbre, level balance and reverberation are still king. Anyone will notice those things immediately if they are off. Unless the spatial L/R imaging is grossly messed up, most people wouldn’t hear a distribution problem, especially if they were not at the live event and had an idea of the actual arrangement. Some more discerning listeners will listen for things like how wide the apparent image is, how even the distribution of those sources are within that width, and how distinct the placement of individual sounds sources are within it. Yet they still only have an imaginary idea of what that should be, unless they were there at the live event (an even in that case I’d argue that what they want is something pleasing, something close to what they think the distribution should be, rather than something that is as geometrically ‘accurate’ from the actual recording position as possible).
Multi-channel surround is two-dimensional, expanding the one-dimensional line between speakers to a horizontal plane around the listener. Same hierarchy of importance: Level, timbre, level balance between sources, direct/reverberant ratio.. then farther down on the list envelopment in the ambience and directional source distribution. But like everything else, the question is not really one of directional or revererent accuracy as much as about presenting something believable and pleasing. As far as the sound source distribution aspect of multichannel, I love hearing a more solid image across the front, the crowd reaction wrapping around the back, the more tangible sonic fingerprint of the room reverberence.
But it’s not only better source distubution that makes stereo superior to mono and muti-channel superior still. Things sound more ‘real’ in stereo than mono, and more so in good multi-channel. The timbre of many instruments is better and ‘more real sounding’, the direct/reverberant balance clearer and less critical to get just right. And if it’s not just right I can adjust it afterwards to some extent. In some ways it’s actually easier to make a decent stereo recording than a mono one, and easier to make a multi-channel one than a stereo one. There is less compromise required in fitting the recording situation to the limits of the medium. For example, a recording that would be way over reberberant from a less than ideal mic position becomes more listenable because the listener can direct her attention to what she wants to hear, more like she can at the live event, and ignore the room reverberence behind, even without the limited adjustments I can make to improve it after the recording is made. It’s somewhat ironic that recording in multichannel is more forgiving in that way. Of course it’s technically more complex to setup, record, mix and playback, but the challenge of ending up with a good sounding recording is actually made easier. Same for stereo over mono.
I think it’s quite a bit more convincing, more real sounding, interesting and cool as well. I wouldn’t make the effort otherwise. It’s also helpful in making the best stereo recordings I can, assuming I have the time to mess with mixing it down, which I rarely do.
To get the 3-dimentions we’d need to record height information. My recordings with the ambisonic mic capture that to a basic extent, but I have no way of playing back the height information currently, other than pointing the virtual microphones up or down a bit to better optimize the 2D sound.
I haven’t heard any of the 11 channel matrix surround decoders, but I can image that a good implementation, properly set up might work quite well with live recordings by distributing the decorelated ambience information (mostly the L-R difference signal) more evenly throughout the room for a stronger feeling of envelopment and ‘your are there-ness’, even though it makes no improvement in the location of actual sound sources. If so, that would make it a good example of the value in improving the ‘suspension of disbelief’ even though there is no improvement in actual accuracy.