1080p at 6 gigs to improve a few seconds of audio? I agree that the first few notes of the main theme feel a bit flat. It just seems a bit counter-intuitive to dramatically reduce the quality of both the audio and video for the rest of the 2+ hours to improve the quality of the audio for a few seconds.

Since you’re looking for help, I’m guessing you might not have the ability to rip the BD yourself. But if by chance you do, a much better option might be for the generous person to just send you the replacement audio track so that you can remux it. It would save them from having to render the film’s video as well.