hairy_hen said:

@TServo2049: I'm honestly not hearing the echo you speak of during the Death Star explosion. I didn't do anything to that part other than add bass from the 1997 mix, which is in its own separate channel and should not interfere with the mains. If there is something there I'm not noticing, it's either in the source track or is some kind of artefact from the upmixing. But I'm just confused about what you mean by this, because it doesn't seem to be showing up on my end.

Actually, listening to it again, it's not an echo.

Using DJ's V3, here's the explosion sound from the '77 stereo, the '85, the '93, and the front L/R channels of your mix.

'77 stereo: http://www.megaupload.com/?d=UVKUB084

'85: http://www.megaupload.com/?d=RUSTLKAO

'93: http://www.megaupload.com/?d=4X2YVMT9

Your mix: http://www.megaupload.com/?d=8OYWQ7J0

Since your mix is based on the '93 mix, I decided to see what happened if I cancelled the two out. Here is what I found when I used GoldWave to mix together the L/R of your 5.1 mix and an inverse of the '93 mix:

http://www.megaupload.com/?d=WW8TKYJW

It sounds to me like part of the explosion sound from the SE. You said that you only used (part of) the bass/LFE from the SE explosion - but it sounds like my initial suspicion was correct, some of the SE explosion sound ended up in the mains (and not just bass frequencies either).