I am surprised that Linkwitz glosses over an important fact:
Stereo recordings are two channel recordings, the combination of which is enough to let you brain know the direction from where sound is coming. However, this combination is supposed to happen inside your brain, not outside.
Unfortunately, most of the stereo reproduction systems, the way they set-up cause cross-channel bleeding: left speaker sound goes to right ear, and right speaker sound goes to left ear. I know many audiophiles prefer this setup, and I am sure many on this forum will argue me to death that this is the ideal situation. But harboring a belief doesn't make it more right. It is not ideal.
Walls, reflections, etc everything is anyway being captured by the microphones, there is no need to have 360-degree firing speakers to recreate the soundstage. I know there are audiophiles who will label this blasphemy, and many on this forum itself who will passionately defend this kind of set-up. But you can't argue the mathematics - and humans have progressed enough to learn about impulse responses, essentially what a transducer like mic captures from an environment=direct + reflected sound. Introducing another set of deliberate reflections is definitely killing the sound stage. (
https://www.hifivision.com/threads/audiophile-monday-tip-7-you-cant-unabsorb-your-room.99202/)
