Moth3r said:

Possibly found the answer in the main thread:

hairy_hen said:

I guess I never did actually mention it here, having only talked about it sporadically in other threads, but there is indeed a new version of the 70mm mix out there. The changes from the previous revision are minimal, with the main improvement coming from having used the Dolby Media Decoder application to upmix the laserdisc audio into five channels with Prologic II, which results in greater channel separation and consequently a more believable sound field.

I'm guessing the audio on ROTJ has not yet been updated with this improved channel separation?

That's correct. Only Star Wars has that.