How did the movie-studio convert "The Exorcist" mono into surround?

[melodram]

Hi,

I always wonder how movie-studios convert mono into surround?

If the film was made with only one mono-track, how do they create 5 channels, like in "The Exorcist"?

[smrpix]

They have the separate clean elements from the original mix and can place them spatially. The music was certainly originally mixed in stereo. In some cases background ambience will be newly created.

They're not starting with a 35mm mono optical track.

[melodram]

Thanx

Even if it was a mono-track?

So, they recordet it in stereo, but showed it in cinemas in mono?

[smrpix]

Most voice recordings even today are made in mono, each actor having their own track. The stereo is created when it is placed spatially in the mix. So the Exorcist would have been remixed from the original elements.

The Exorcist was remixed in stereo for a 1990s reissue.

[melodram]

I read that Exorcist was remixed in stereo for the 1979-reissue.

I just wonder why they didnt show the movie in stereo in 1973.

[melodram]

Or they play the film in a studio and record it new with 5 tracks/channels.

[filmboss80]

The late Rick Chace pioneered a motion picture sound restoration process in the mid-1980s (Chace Surround Stereo) which cleaned up the mono optical soundtracks, isolated and separated the sound elements (through frequency cancellation, usually), and produced fully remixed stereo magnetic tracks for many classic movies. The process has been updated over the years. For the latest Exorcist re-release, they did this:

http://www.filmsound.org/movielist/E/Excorsist/post_exorcist.html

[melodram]

Thanx!

I have the Bluray and on the theatrical version, the dialogue sounds good. On the "Direcors Cut", it sounds scratchy, especially when somebody talks loud or screams. And when Regan says "Let him f*ck you", its stereo on the theatrical cut and mono on the "Direcors Cut". I wondered about that.