Moth3r said:

Jonno said:

Great additional info! Let's see if we can summarise then:

...

1995 THX laserdisc - 5.1 AC-3 and 2.0 PCM (based on 6-track 70mm master)

Although the AC3 is stated as being from the 70mm 6-track, I'm wondering if the PCM on this LD could be based on the 35mm Dolby Stereo mix? That would be interesting.

From the cover scan that msycamore posted, "The six-track magnetic sound masters used in the original 70mm theatrical prints were utilized to create the sound tracks for this widescreen laser disc release of Alien." So yeah, I take it to be both tracks, even though the PCM couldn't possibly replicate all of the channel information (correct me if I'm wrong). If only all releases had this kind of useful information printed on them...

More frustrating reading in this Blu-ray.com thread. The guy is completely confident that the 70mm was the source for the 4.1, but doesn't explain how he knows that. The lack of dialogue differences would certainly indicate otherwise (hopefully someone else with the Blu can back me up on this!)

And in any case, wouldn't the proper representation of this particular 6-track mix (with split surrounds) be 5.1? Seems more likely that this 4.1 would be an honestly-labelled repeat of the mono-surround 35mm upmix from 1999.

An awesome opportunity here, by the way... sadly I'm at the wrong end of the UK to enjoy this 70mm screening!