From: hafner@ifi.unizh.ch (Michel Hafner)
Subject: Re: What sound quality should you expect from films?
Keywords: KODAK, CDS, DOLBY SR
Organization: University of Zurich, Department of Computer Science
Date: Sat, 2 Jan 93 13:25:29 GMT

In article <1993Jan2.021837.10994@cc.umontreal.ca> durandm@ERE.UMontreal.CA (Durand Martin) writes:
>In article <1992Dec28.072327.24351@daffy.cs.wisc.edu> quale@saavik.cs.wisc.edu writes:
>[reply about article deleted...]
>>
>>Sorry, Dolby Digital is strictly a 35mm format.  If you see it in 70mm,
>>it will be in the Dolby A type noise reduction magnetic 6-track analog
>>recording, which has greater headroom (louder louds without clipping)
>>than Dolby Digital.  Dolby Laboratories has no immediate plans to release
>>a 70mm digital format.  The 35mm Dolby SR *D format (Dolby Digital) was
>>created to give 35mm prints the same discrete 6-track sound quality as
>>expensive 70mm prints.  Both formats are excellent and in properly tuned
>>rooms both are an experience worth listening to.
>>Doug Quale
>Doug, I'm not shure if you're aware about the latest breakthrought in sound
>processing - the KODAK CDS (Cinema Digital Sound). This process is, by far,
>the best one I know (it's even better than THX!!!).

Once again, THX is no particular sound medium or sound storing process. It's a 
set of implemented design and quality control standards for theatre sound
presentation. It works with mono, stereo, analogue, digital, dolby...you name
it.

>The sound is digitally encoded on the film in a manner which ressembles the
>digital encoding of home CD's (yes the one you play at home!). The projector
>is mounted with a special CCD reader (just like the CCD in your camcorder) and
>it reads the encoded signal. Once processed, it can deliver FULL SPECTRUM audio
>digital sound to all the six channels of speakers that are installed inside the hall (5 full bandwidth + one subwoofer speakers). The side channel speaker soundresponse is astonishing, you've never seen (I mean heard) anything like it.
>
>Last year, in Montreal, we had a special demonstration of the CDS. It was made
>by KODAK representatives and was held in a theatre of the NATIONAL FILM BOARD
>of Canada. They showed a release of TERMINATOR 2 and a film sampler made by 
>KODAK to demonstrate the capabilities of the system.
>
>B
>One of the main advantage of CDS over standard DOLBY is the fact that the 
>digitally encoded signal does not degrade over time nor if the film is dama-
>ged. Even scratches can't hurt the signal. After 500 or more viewing of the 
>same copy, the film sounds the same!
>
>The only thing is that the system is costly. It costs as much as 20,000$ to
>install the CCD in the projector. I hope that theatres will soon switch to 
>CDS. It's the best sound system I've ever heard!

Dolby SR D is also digital and has the big advantage of requiring only one type
of print for all 35mm houses instead of two as CDS does. Therefore CDS is
pretty dead at the moment. Since "T2" no film was released in that format and
the partner of Kodak ( Optical Radiation Co. ) has left this business some-
time ago. I guess the future belongs to Dolby SR D for digital sound on 35mm
movies.
								M.H.

Newsgroups: rec.arts.movies