Yes you are correct and I wasn’t trying to conflate the two. But the idea still stands that for Fantasia they recorded 8 individual tracks to send to whatever speaker they wanted to. In a modern recording a sound engineer might just decide on a permanent playback speaker depending on where the instrument is physically located in the soundspace. But thats not to say they couldnt feed, say a woodwinds mic, through the left then right then rear etc. to create movingc clarinets. Its very possible today but A LOT more work and ultimately based on a creative decision.
So I’ve tried to distill what is missing from today vs then. If you take it down to the most basic elements you had
8 input tracks
- 1-6, instrument pickups
- 7, mix of 1-6
- 8, a distant mic
3 output speakers(or 5 if you used Mark X)
- Left
- Center
- Right
What we have today is a mono track (possibly a mix of input track 7 and 8) and a stereo track of which I don’t know how the mix down was performed from the initial tracks.
Ultimately the point being that the dolby 1990 mix is the best separation we’ll get but there is still potential for a 5.0 true remake of it on modern computers, which would be more accurate than the DVD version.