Thanks for that, belbucus, it provides a real insight into a much discussed topic here. What's most interesting is the description of how the original 70mm 6-track mix for Star Wars was derived from the 4-track master. This is basically what I had assumed, but was unsure of. What it means to me is that the perceived "holy grail" of the 70mm mix is not that at all, and that for home theater, a mix derived from the 4-track master should, in fact be better. Now we know that the '93 mix combined some of each, with additional effects. What I would love to read is a similar explanation about the creation of the '85 mix.