hairy_hen said:
I've double-checked once again just to be sure everything sounds the way it should, and I'm pleased to report that the 5.1 mix is now entirely finished and ready for general use. Here are the download links from Satanika--an AC3 of 448 kbps split into two RAR files. It should be all set to mux with any GOUT-derived video, whether you use the video as is or with your choice of AviSynth script processing.
Part 1: http://www.sendspace.com/file/qq11vb
Part 2: http://www.sendspace.com/file/jd98ys
If any of the links for this or the stereo version expire, just let me know and I'll be happy to re-upload them. I've also updated the first post to include the download links for both so they'll be easy to find.
With two different versions of the soundtrack, there may be some potential confusion about differences between them and which one would best serve a particular type of audio setup. I'll try to make that clear here.
The original 70mm mix featured discrete channels in what we would now probably call a 4.2 layout, with three front screen channels, a mono surround channel driving an array of speakers in the sides and back, and two channels exclusively reserved for low frequency effects, driving whatever speakers or subwoofers a particular theatre was equipped with. The laserdisc mixes from which this recreation is derived are in a matrixed stereo format, with the four main channels folded down into two, encoded in such a way that it can be expanded or "upmixed" back into surround. Note however that this upmixing cannot fully separate the channels from each other, and a certain amount of crosstalk between them will exist regardless of what algorithm is used. The original discrete channel format cannot be fully recovered without an actual transfer from the source, only approximated.
Such upmixing is normally carried out by the receiver during playback, and the stereo version heard this way will deliver excellent results. The bass content, however, will be limited to what is present in the laserdisc mix (which is not insignificant). The 5.1 version was made in order to allow use of the LFE channel, since this was an important part of the 70mm theatrical experience. The upmixing took place in software, with the ATSurround plugin of Foobar 2000 I believe (correct me if I misremembered that), and the LFE channel added in afterwards. The surround experience is very similar to the results from Prologic II, and the added bass gives considerable impact to explosions and spaceship flybys, as well as some more subtle low end. Surround effects emanate equally from both rear speakers, with additional rear stereo ambience derived from the mains.
Which one you should use depends what kind of sound system is being used. I'll give some general guidelines:
If you are listening via 2-channel analog connection, be it the headphone jack of a computer or the stereo out of a dvd player, choose the stereo mix. This applies regardless of whether you are using your tv speakers or large floorstanding tower speakers, and whether you have a surround setup or not.
If you have a 5.1 setup, and are bitstreaming the AC3 signal to a Dolby Digital decoder using a digital connection, or are using a multi-channel analog connection, you should definitely choose the 5.1 version.
If you use a digital connection but do not have a full 5.1 system, you should most likely choose the stereo version. Use your choice of upmixing algorithms in your receiver to match the signal to your speaker layout if you wish.
If you have a subwoofer but less than five speakers, you may achieve acceptable results from using the 5.1 mix, but be aware that by downmixing a file that has already been upmixed from stereo, the quality of sound from the main channels will most likely be inferior to what you will hear from the stereo mix, due to phase artefacts and channel crosstalk. Were the original discrete mix available, it could be downmixed without any significant problems, but that is not the case with this version.
(If you really want to, you could encode your own AC3 in 2.1 layout using the stereo and LFE tracks I've provided, but know going in that the playback of such a format is erratic, depending entirely on the equipment used. My own Onkyo receiver discards the LFE channel when using Prologic II, retaining it only in stereo and DTS Neo:6 modes. A high-end Denon receiver at a hifi home theatre store was completely incapable of using the LFE channel at all, regardless of what listening mode was used; a similarly priced Yamaha successfully used the LFE while automatically engaging THX Surround Decode, and worked in stereo as well. I make no guarantees about going this route.)
I don't know what the surround effect of this mix is like on a 6.1 or 7.1 system, through Prologic IIx or similar algorithms. Ideally the rear channel effects would be spread equally among all the back speakers, to simulate the monaural surround of the original, rather than being relegated to the center back speakers only, but I can't say one way or the other, having never heard it this way.
Anyway, I've gone on a bit, but hopefully these guidelines will be helpful in creating an ideal listening experience for the film. I really hope everyone who obtains this mix will be pleased with it, and I'm very interested in hearing any opinions and feedback you might have. Have to say I'm rather relieved at finally being finished with this--hopefully now I can just watch the film without worrying too much about the sound not being quite what I want it to be! However close this comes to simulating the real 70mm mix, if I've improved the available sonic experience of the film for anyone, through the sound itself or from providing a look back into the film's history, then I've done what I set out to do.
Hairy_hen
Fair play to you what qualifications do you have in this venture into creating the so called original 1977 70mm DOLBY STEREO release?
I’ll have thee copies free please on DVD region1 or region0 please and I’ll give it my fullest DOLBY listening attention!