According to this the original mix was available in 1997, but since its channel layout wasn't directly compatible with AC-3 it was decided to do a new mix.M-A wrote: Fri Sep 16, 2022 12:11 amYes, I believe that the 90s mix (the one included on the german 4k) is a recreation of the original mix supervised by the original mixers after the 1979 mix was presumed lost, so it technically is not the original audio, but it is the closest thing![]()
Getting a bit more into the weeds, I think the only way to accurately represent the '79 mix on video would be with something like a 5.2 track. Format 43 as used on the 70mm Apocalypse was basically Format 42 (FL, FLC, FC, FRC, FR, Rear Surround—the same configuration as 70mm Todd-AO, but with the FLC and FRC speakers used as LFEs) with additional left and right surrounds matrixed into the FLC and FRC channels, which implies you still had separation for the two LFEs. This would seem to backed up by the diagram of the speaker configuration included in the manual for the split-surround module. (This configuration is also largely identical to that used for Cinerama 7-track, with the difference that Cinerama used the FLC and FRC speakers for full-range audio and had two mid-surround wall speakers that could either be separately fed from tracks 6 or 7 or share a single channel, with track 7 then used for a rear speaker.) Was there a technical issue that prevented the use of separate audio for the two LFEs, or was it just decided that there was no real benefit to doing so and all Format 43 mixes treated them as a single LFE channel? The manual linked above says the Todd-AO FLC/FRC speakers were repurposed for LFE by Dolby because that degree of fine separation was unnecessary on anything except very large screens, so it seems plausible that the two LFEs were never actually separated. If they were separated you could approximate that using an Atmos 9.1 layout, but I don't think that's a common configuration in home theaters.