- Time
- Post link
Dolby Stereo/SR mixes are made with the intention of being played back upmixed from matrixed two-channel. As such, compromises may be made in order to achieve the best possible sound in this configuration. I noticed that all of the 35mm stereo mixes for the SW films have significantly narrower stereo imaging than the 1993 versions, which was most likely done to reduce the amount of unwanted crosstalk into the surround, particularly since upmixing was not nearly as sophisticated in those days.
Some recent Bluray releases have been including 4.0 mixes, which are direct copies of the discrete tracks the SR versions are made from. However, they will not sound exactly the same as the two-channel versions, and according to Dolby documentation may not represent the intentions of the mixers completely, since the matrixing adjustments are still there but not combining the way they would have. Still, that's probably a fairly subtle point on the whole.
5.1 configuration would be relatively easy to obtain from this 4.0, either by having the surrounds play the same thing or by introducing panning into the rears as appropriate. The LFE channel is trickier to derive, and on principle Dolby discourages the creation of additional bass by copying and augmenting what is present in the main channels, since it can introduce phase cancellation or other errors, particularly when dealing with an upmix. LFE should be created by separate access to the sound effects.
I ran into this exact problem in doing the SW 70mm. For the most part I used the discrete LFE of the '97 and '04 mixes, but in a few cases chose to go with bass from the '93 versions because they just sounded better combined with the mains, but the level and phase required adjustment to come out sounding correct. So I guess you could say I knowingly went against Dolby's guidelines occasionally. ;)
