Looking for any info on Dolby SR*D, DTS and SDDS

[Juergen Zweers]

Hi all, My name is Jürgen, projectionist at an independent cinema run by students in Amsterdam.

For my thesis on digital film sound I am looking for any info on SR*D, DTS and SDDS sound, ie. publications but also your personal experiences and stories as seasoned projectionists! I personally work with SR*D on a CP650, but have little experience with DTS and no experience with SDDS. The goal of my thesis is to describe the history of these three versions of digital sound and how SDDS didn't catch on as much as Dolby and DTS.

I'm looking forward to reading your stories! Thanks so much in advance,

Jürgen

[David Ferguson]

If you're looking for stories from people who have used these systems, then possibly the best place is this forum - in particular the forum archive. If you do some reading there you'll find literally hundreds of posts from people who are using these digital systems. Of course, there will be a bit of a bias towards people encountering issues and looking for help, but that might help give you an idea of the common issues with each system. A few of the common ones that spring to mind are the reliance on the distributor sending out DTS discs, or scratches impacting the playback of SDDS.

For the history of SR*D, possibly the best place is a few articles in the Projected Picture Trust's magazine, written by an ex-Dolby engineer (Dion Hansen) who worked on the process. You do have to be a paying member to access the magazine archive, but there's a student rate, and if you're looking for a first hand account of the development of Dolby Digital then I would think it's worth it. Magazine numbers 157 and 158 will be the ones you want to look at, for "Development of Dolby Digital on film" and "Dolby Digital demonstrations" respectively. There's actually a freely available PDF on Motion Picture Sound, also by Dion, that contains a section about Dolby Digital, but in less detail than the two articles.

For DTS, there used to be a couple of people from DTS/Datasat on the forum, but I don't think they're here any more, and I don't think Datasat is currently in the film business in any way either. At least, they've never replied to emails I've sent!

[Emiel de Jong]

Hi Jürgen, good to see a Kriterion projectionist on this forum! I have not visited Kriterion many times (that would have been different when years ago the Amsterdam film academy had accepted me as a student ;-) but the few occasions I was there I enjoyed very much. It's what David said: in the archives of this forum you will find a treasure of hands-on reports about the various digital film sound systems from very experienced people. And I hope a lot of them will chime in here to answer your questions. Much success with your thesis, I hope to read it some day!

[Marcel Birgelen]

Something I didn't know, but learned via this forum about SRD: Dolby can upgrade (at least parts of) your SRD decoder via film. Apparently, every 35mm SRD release up until now, still contains the latest firmware. The information is side-loaded into the raw data itself, alongside the AC-3 compressed audio-data. I don't know about the bit-rate, but I guess it uses a fair bit of error-correction too.

[Steve Guttag]

The auto update is part of what killed off the DA10. It could auto update ONCE...on the second update, it could crash. Yet another nifty feature of Dolby Digital was splice cache. It would load up the information for the sound around the end-of-reel splice. As such, when the end of reel splice came through, the processor could fill in the missing bits associated with the splice (even the best fo tape splices will put the digital bits out of focus on the reader due to the thickness of the tape as well as any opacity).

[David Ferguson]

I knew about the auto-updating, but didn't know about the splice cache - that's a very neat idea! I've always wanted to know how exactly the data was encoded on the film, but when I asked Dolby about it they said that they weren't telling because it would require a legal review which would be expensive. Sad!

[Juergen Zweers]

Thank you for all the suggestions! I am scavenging the forum archive and have purchased a student membership for PPT.

Hi Jürgen, good to see a Kriterion projectionist on this forum!

It's Studio/K! But it's from the same organization as Kriterion ;-)