hairy_hen said:

The two channel version of the 70mm track isn't in the Despecialized Edition—what I was referring to there was the actual 35mm stereo mix, which I also encoded to AC3 along with the mono. The links are there just in case there were any problems with the tracks in the first mkv.

That reminds me of something I'd forgotten to point out, though: since the 5.1 mix was created by upmixing a stereo track and is not truly discrete, downmixing it back to stereo again is inadvisable. There is a distinct possibility that doing so could cause phase problems, most likely heard as distortion in the high frequencies, which obviously is a less than optimal listening experience. The most obvious cause of such phase problems would be the fact that the surround channels (which contain a certain amount of unavoidable crosstalk from the front) are delayed by 10 milliseconds, and definitely won't align properly in a downmix. Add this to the fact that Dolby Digital decoders may drop the LFE channel when downmixing, in which case the main benefit of the 5.1—namely, the added bass content—would go unheard.

So if, for example, you will be listening to the movie on headphones, or any system without a subwoofer installed, then the two channel version of the 70mm track could make for a more optimal listening experience.

Since it isn't included here, due to the 5.1 more properly representing the theatrical experience, the user would have to mux it in themselves, but it may be worthwhile depending on what kind of listening setup is being used. The links for it are in this post if anyone doesn't have it yet.

Very cool, but had I known all that yesterday, I probably would have muxed it in before rereleasing. I think I just won't be worrying about it going forward...just too much of a hassle.