Still several things to be done with the LFE channel, and I tend to spend a while fine-tuning each detail until I'm sure it's exactly right; but I've been pretty focused lately and am confident that it will come out the way I'm hoping. Even when not working on it, I've often been going over possible editing solutions in my mind, so I have a good idea what to do for most of it even beforehand.

Once the upmix is done, there are a couple things I want to tweak about the imaging, if possible, so that will be a new experience for me to edit in multichannel rather than stereo. If it turns out as I want, some concerns I've had about too much information occasionally being sent to the centre channel will be addressed.

Editing to add: About 4.1 . . . yes, technically this would most correctly represent the original mix, which had monaural surround information. However, the surround cues that are found in the 1993 mix are themselves monaural, and when upmixed will play equally from both surround speakers in a 5.1 setup, each at -3 db to maintain constant acoustic power. In Prologic II using movie mode, and other similar algorithms, the surround cues are played back out of phase with each other to help disperse them and avoid direct phantom imaging, partially simulating the effect of the multi-speaker arrays found in movie theatres, according to THX recommendations.

The only actual stereo content that will be present in the rear channels is low-level duplication from the front (controlled levels of crosstalk between channels, essentially), again for the sake of ambience. The effect of the upmix cannot exactly represent what the true discrete 70mm version would have sounded like, but given the source materials available it's about as close as it's currently possible to get. Add in the extra bass from the LFE and things are sounding great. ;)