I submit that this same notion goes back even further than BACCH or SVS... to the early 80's (and possibly before that) and the days of Bob Carver and his "sonic holography". I actually have one of his C-9 sonic hologram generator units installed in the "tape loop" of my own vintage analog system (that also includes such rare relics as a DBX 224 noise reduction unit, a Nakamichi CR-7a cassette deck that includes Dolby B/C noise reduction as well as automatic azimuth calibration for different tape media, DBX 14/10 EQ, etc.). Again, very much based on eliminating cross-talk (i.e. isolating L and R channels arriving at your ears, to match binaural recording).
Through Google I found some interesting historical references on this subject:
(1) Quadraphonicquad.com
forum discussion of C-9 Sonic Hologram Generator
(2) Semi-interesting but very limited
video discussion of "Bob Carver's sonic holography" by Paul McGowan (founder of PS Audio, who claims his own patents and work in the same general field).
(3) Relatively basic
summary article from 1980 in Washington Post (which you may or may not be able to read) of Carver C-4000 preamp with built-in sonic hologram generator functionality.
(4)
PDF of December 1981 High Fidelity Magazine that supposedly includes an equipment review of the C9 on page 33 (of the magazine), but unfortunately those pages are missing from the PDF! However on page 65 of the PDF (actually page 69 of the magazine) there is what perhaps is a paid-ad ("circle 7 on the reader-service card" and mail it in, if you want additional information sent back to you from the manufacturer... if you remember how these old PAPER magazines used to work!!) which is a Q&A from Bob Carver himself, "telling you briefly how Sonic Holography" works.
(5)
PDF of March 1981 Popular Electronics Magazine that actually does include on page 20 an equipment review of the "standalone" Carver C-9 processor. Previously it was available included as part of the C-4000 preamp.
(6) Useful comments from another online forum discussion:
"Although this is an active process, it essentialy feeds out of phase L and R signals to the opposite channel in an effort to keep the left and right channels from being heard by the opposite ear. Think of a wall straight out from your face perfectly separating the left and right channels with no crosstalk to the opposite ear, thus eliminating the smearing effect caused by your brain hearing L R locational sound being heard in the wrong ear. Carver Hologram generators basically do this electronically. The concept is a sound one, but hard to implement perfectly. Sonic Holography requires extreme care in speaker setup and a perfectly placed listening position, otherwise it does not work well and I think the biggest reason (poor setup) why the unit is unfairly criticized. BUT, when dialed in correctly, it can be overwhelming as to how well it presents the space in a recording; especially the reverb, decay, and ambiance in well done recordings. It also can throw audio all over the room emulating multi speaker setups. Sound can appear to come from outside, behind, or in front of the speakers..... and even from behind the listener depending on the recording. Sometimes it can mimic being in the middle of a studio surrounded by the musicians. This is dependent on the particular recording."
"What really triggered this post is that today I listened to Jean-Michel Jarre's new
Welcome To The Other Side release. It is, by far, the album that best takes advantage of the C-9's capabilities, of all the albums I've listened to so far. On the tracks
Oxygene 2 and
Oxygene 4 in particular, I had to check more than once to make sure I was listening to a stereo system, and not the full 7.1 system in that room. There were synth notes moving in an arch across the top of my head, the full width of the room, and even slightly behind me. It was as close to a discrete surround sound experience as I've ever heard - from two stereo speakers at the front of the room!"