When released in cinemas, the 70mm prints of these films apparently had a 6-track sound mix. I assume the Dolby Digital on the DVDs was made from these 6 channels. But where were the original 6 channels placed? From reading up on the history of movie sound, it seems there were at least 3 different types of 70mm 6-track sound. My guess is that Indy uses the version with 5 front speakers, i.e. a mid-left and a mid-right in addition to the usual 3. The sixth is a mono surround. This is because when I listened to Temple of Doom, it seemed that on many occasions the dialogue for an actor on-screen, but off-centre, seemed to come from somewhere midway between the centre speaker and the front left/right. Also there were no obvious points where the surrounds were working in stereo, and no obvious use of the LFE channel. This is just a guess though. Anyone know if I'm right?