While it's a common practice for most major studios to do brand-new 5.1 Surround mixes for the classic catalog titles, sometimes they just repurpose old stems.

If you use this forum Dolby Stereo doesn't need an introduction but if you somehow don't know the TLDR is essentially Dolby Stereo was a technique of getting 4 channels of audio (LCRS) to fit into the usual optical stereo track on a 35mm reel via matrixing (if you want to a longer explanation, check here: https://fanrestore.com/thread-3467.html). Sometimes these mixes would play in discrete "Baby Boom" format in 70mm, hence the 70mm Six-Track part of the thread name. Now in the early days of surround sound on Home Media, many releases would choose to just use their existing Dolby Stereo track and process them back to surround (Much like a theater would've done during the original run). Having an interest in these mixes, I have found a way to identify if a release is using an unfolded Dolby Stereo track. 

Software Needed -
Audacity + FFMPEG Plugin
gmkvextractGUI (optional, if extracting from a remuxed source)

For my main example, I'll be using a personal favorite of mine that has two 5.1 tracks on different home media release. Dune (1984).

Below is a screenshot of the surround channels on the 1998 Universal DVD



Now you might already be able to tell that the surround channels look to be the same in both channels. This is the first step in identifying as Dolby Stereo only ever used a single mono surround channel. However the second step is the real smoking gun to prove that this is a Dolby Stereo unfold/Six-Track Mix
By right click on the the leftmost side of the track in Audacity, you can change the track view to Spectrogram which reveals...



Matrixing in the surrounds! The spectrogram can easily show the results of the matrix decoding process which makes it HIGHLY likely a track is an unfolded Dolby Stereo track. Now this isn't 100% definitive for one of those 2 reasons.
1. This is age/budget dependant, Some films had discrete mono surrounds while other relied on matrixing, There's also rare case of a film's original mix having stereo surrounds but being released in Dolby Stereo (i.e Indiana Jones, Popeyes).
2. There are rare cases of remixes using matrixed surrounds (again, Indiana Jones) and/or stereoizing the mono surrounds (Blade Runner). So beware of those.

With that being said I hope this is a useful guide for those looking to find 70mm Six-Tracks or Dolby Stereo unfolds on older releases, Cheers!

Hi everyone found this community, looking for a few restorations. Hopeing one day buffy gets one.

Hi guys.

Ferris Bueller’s day off
Planes trains and automobiles
Home alone
Home alone 2
Mrs. Doubtfire (its Chris Columbus but whatever)
Airplane!
Airplane 2
Naked Gun 1 2 and 3

Any laserdisc rips for any of these?

Hey everyone, I love classic Hong Kong cinema and want to see some resto's of such, show me!

Working on a big Blade Runner preservation project that's more on the pirate side so I am sadly not allowed to share the full thing here, much like my T2 project. I do however want to share my syncs of the Laserdisc audio for the Theatrical cuts, both bit-perfect captures.

U.S Theatrical sync is sourced from the 1987 US Laserdisc, I would have liked to get a digital capture from the JP Laserdisc but my source only had the US one. Despite being analog it doesn't sound all too bad, I also checked and yes it does have proper Dolby Stereo matrixing.

International Theatrical sync is sourced from the 1989 Criterion LD [CC1169L], I also had a cap of [CC1120L] and they sounded identically. The sync has +3db gain applied since the original cap was rather quiet sounding.

Both are synced to the Archival Cuts Blu-Ray and are 44.1kHz FLAC 2.0, freely available to all forum members new and old.

The otherwise good Criterion release of Robert Zemeckis’ I Wanna Hold Your Hand (1978) strangely did not include the original mono mix. It only includes the 5.1 surround mix made for the DVD which in typical Universal fashion is laden with intrusive and unnecessary foley and muddy dialogue. 

The original mono mix is available on both USA and Japan laserdisc. There’s a few listings on LDDB for decent prices. 

I’d love if someone out there has it and would be willing to rip it so it can sync it.

Thanks in advance!

hei hei

hola a todos soy de España

Hi!!!