Quoted from Rdoyle1978:The default mix is on the PinSound Community site. Yes, to quote your own phrasing: "[If] the source audio is of low-res in the first place the only way to get higher res is to find a remastering of the audio."
There's a pinsider who created absolutely THE end-all-be-all IJ mix. His name escapes me right now but it's basically the only mix you'd want, and it is ABSOLUTELY a game-changer. He painstakingly took the music from all 3 films, found the identical callouts from the films, and a bunch of other easter egg type things, and put them all into a (huge!) sound mix. He asks for a minimal donation, which is absolutely deserved given the huge amount of work (seriously, I bet it took him 200 hours). The only thing to be aware of is that because there are so many files, and in such high res, they are big, and they require a very very fast USB drive. The sounds will lag if you have just a run of the mill one. I'll try to think of his name. Perhaps somebody else can chime in with it -
EDIT: Here's a Youtube of a really really really early version.
The pinsider's name is Endprodukt. Wonderful guy -
Wow!