belbucus, thanks for getting back to this, and for bringing useful new information. That Mike Minkler interview certainly does seem to contradict Dave Schnuelle's description. My support for the 4-track master was based on the fact that I don't like the idea of the inauthentic '93 mix or the limiting present in the 35mm print master (despite theatrical authenticity), nor did it seem sensible to have a boom track created in the way Schnuelle describes for the 6-track mix (if he was right, you could more or less recreate this effect at home from the 4-track master anyway). However, from what Minkler says and from your own observations, it looks as if the best option might be 4.1 derived exclusively from the 6-track master. I said above that this would be the most authentic 4.1 mix and it now seems as if it might also be the "best" mix.

Do you have any information regarding the origins of the Laserdisc mixes prior to 1993?