trying to capture the illusion of the ambiance in a performance space. The problem is that it can only be an approximation because the room or space where the recording takes place will be different from the room where it will be heard.
Everything in this hobby is an approximation…the goal is to make that approximation as good as possible. With an immersive recording, the goal is to replace the ambiance of your listening room with the ambiance of the performance space.
It'shard to make 73mS of delay mixed with the other delays that make up the reverberation in a large hall sound correct in a room that's 8' high, 12' wide and 19' long.
Not really. Those reverberations being played directly at your ear by a surround speaker will generally overwhelm the reverberations caused by your own room enough that your brain will focus on them instead. Yes, your room’s acoustics will always be there and a better room will sound better, but in general you want to treat a room for multi-channel more than one would for pure two channel listening. Even if the room doesn't allow it to be done perfectly, it's certainly done a whole lot better than two speakers at the front of the room playing them out of phase can accomplish.
The number of speakers needed for that would be incredible because of the many reflection points and paths in a larger room.
Again, not really. Humans don’t resolve the direction of sounds from beside/behind/above nearly as well as they do from the front. When you’re in a concert hall you aren’t hearing thousands of individual reflections
individually. You’re hearing “summations” of them coming from various directions. When you point microphones in those directions, record those summations, then play them back from speakers from those same directions, the result can be quite convincing indeed. And it’s “as real as it gets.”
To flip that around, if you don’t think 5, 9, 11 or 13 speakers is enough to pull it off, you certainly can’t think 2 speakers can do it? Two speakers playing all those reflections out of phase from the front of the room is just no match for additional speakers playing them back from the direction they came from in the original performance space.
And to quote Dr Floyd Toole on the subject of the limitations of Stereo….
Why doesn’t it sound “real’? Because it can’t. A small number of microphones cannot capture the 3D sound field around performers, and two channels and two loudspeakers of any design cannot reconstruct a realistic sound field. It is the daunting task of recording engineers to do what is possible to deliver a semblance of something real, if that is the goal, or to create an artificial “stereo” variation that is stimulating and entertaining. We need multichannel.
