On page 32 of the latest edition of DVD review there is an interview with Matthew Wood:

Regarding the sound mix he says:

We have everything here that I could go through and all we have is a 4 track master that we used in 1997 to create the special editions; music,sound effects and dialogue all layered on top of each other with no separation.

So starting in 2004 we began the meticulouse job of going throughall the original elements of sound effects that were in Ben Burtts library.

Finding the original music masters and putting those back in synchronisation with the picture , and then pulling the dialogue from the original 1/4 inch master tapes and all the ADR masters to create a 5.1 or 6.1 master.It was a meticulouse labour of love to make sure every single sound effect,piece of dialogue and music that you heard was from the original..

It was'nt going to be a new piece of dialogue or a new take that you were not familiar with.It all had to have the emotional impact of the original, we just had to update it for the modern soundstage.

We would play the 4 track master that was used in the 70's then carried through the 80's VHS period,through the laserdisc period in the 90's then up until the special editions, then play back all the elements that we had put together from miles and miles of magnetic tape that we transfered into pro tools,rebuilding it in 30 second increments, listening for the right laser, the right darth vader breath,the right foot step.

Luckily we are both huge star wars fans(Wood and Dave Accord--clone wars sound designer) so it was not hard to do because if things were not right you just felt it.

We used our huge fandom as well as our professional prowess to make it work.