This is topic Soundtrack Format in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Mitchell Dvoskin (Member # 751) on 06-07-2002, 12:10 PM:
Is there any free site(s) on the internet that lists whether a film is Dolby A or Dolby SR. The Dolby site only lists whether it was Dolby (not the type)./Mitchell
Posted by Paul G. Thompson (Member # 655) on 06-07-2002, 12:39 PM:
Mitchell, I have not known of Dolby "A" prints that have been produced in years. If there were, they are far and few in between.
Posted by Michael Brown (Member # 890) on 06-07-2002, 05:27 PM:
If there is a particular film in mind, then open a thread in the 'Feature info' forum and I’m sure someone will try to help.
Posted by Brad Miller (Member # 2) on 06-07-2002, 06:25 PM:
Dolby SR came about when, around 1997? (I'm sure someone will answer that definitively.) Anything before that will automatically be A. Generally though if it says "stereo" or "dolby stereo" on the leaders, it's A noise reduction. If it's SR, it will ALWAYS say "SR" on the leaders. The problem of course comes during the days of dual inventory where a theater may have gotten two prints, one in SR and the other in A. Few people pay attention to which set of cans they are breaking a certain print into.
Posted by Michael Brown (Member # 890) on 06-07-2002, 06:37 PM:
quote:
Dolby SR came about when, around 1997?
Um 1987 Brad?
Posted by Joe Beres (Member # 678) on 06-07-2002, 06:53 PM:
A friend of mine that used to run screening rooms for Dolby told me that running a Dolby A print with SR format on the processor will not sound noticeably different than running it with the specific Dolby A format. That being said, when in doubt, just run the film in SR.
Posted by Steve Guttag (Member # 268) on 06-07-2002, 07:28 PM:
Joe, if your friend in fact said that...then he is a fool and I don't care who he is. The two noise reductions are dramtically different and in particular, the SR has a narrow right vs wrong tracking. If either the NR or the media is a little off, SR will show it more dramatically. Steve
------------------
"Old projectionists never die, they just changeover!"
Posted by Joe Beres (Member # 678) on 06-07-2002, 07:49 PM:
Steve, somehow, I knew that you would jump on me for that one. He did say it, but I certainly don't doubt your knowledge. However, in a case when you really can't figure out if you have a Dolby A or SR track (either by examining leaders or listening to a bit of the track), which is the better format to use? In other words, What is the lesser of the two evils, running A in SR or running SR in A?
Posted by Gordon McLeod (Member # 33) on 06-07-2002, 08:11 PM:
It would sound better to play a SR print in A type than a A type in SR but better to just get it right 
Posted by Joe Beres (Member # 678) on 06-07-2002, 08:33 PM:
Is there a way to determine whether a track is SR or A (without the aid of labeled leaders or listening to the quality of reproduction in both formats) by examining the track itself? Are there telltale signs that could give you clues as to what it might be?
Posted by Gordon McLeod (Member # 33) on 06-07-2002, 09:29 PM:
none
Posted by Brad Miller (Member # 2) on 06-07-2002, 09:38 PM:
Yes I meant sometime around 1987. Typo. Anyone know the exact year?
Posted by David Stambaugh (Member # 1102) on 06-07-2002, 09:44 PM:
The first movie I was specifically aware of being in SR was U2's concert film "Rattle And Hum". That was 1988. Had to be very close to that date, maybe 1987 as Brad suggested.
Posted by Frank Angel (Member # 248) on 06-07-2002, 11:33 PM:
In those early days, they would double inventory A and mono prints, because Dolby's position, correctly, was that playing back A prints without Dolby A N/R will sound like dog doody. Anyone in a recording studio will attest to this: playing back either a Dolby A tape without N/R or playing a non-A tape with A noise reduction switched on will be obviouly "way wrong," even to the layman's ears. Yet when the studios started to balk at the chaos that always ensues with double-inventories, Dolby quietly backed away from their original stance and pretty much let the studios send A prints to theatres without any cinema processors at all, dropping double inventories. BUT for some reason, playing N/R prints without any N/R doesn't sound quite as bad as I remember playing an N/R master tapes without N/R used to sound -- with the tape you hear all that pumping and hiss and high end frequency levels changing all over the place. I don't hear that as much with film, yet I have never heard that the Dolby A or SR N/R is any different in cinema or audio studio processors -- A is A and SR is SR, no?
Posted by Steve Kraus (Member # 476) on 06-07-2002, 11:50 PM:
"Star Trek IV The Voyage Home" (aka Star Trek IV Save the Whales) had two 70mm prints with SR NR. That was a 1986 release.
Posted by Christos Mitsakis (Member # 143) on 06-08-2002, 07:00 AM:
Dolby SR was first introduced for the audio industry in March 1986.
The same year the 35mm optical SR format was demonstrated to A.M.P.A.S.
However, the first films using SR NR were Innerspace and Robocop in 1987. Robocop was my first SR presentation back then.Regards,
Christos.
Posted by Paul Linfesty (Member # 214) on 06-08-2002, 08:42 AM:
I saw one of those two prints of STAR TREK IV at the Village Westwood. The other, if memory serves, played the Cinerama Dome in Hollywood. Dolby used a new logo for this introduction of SR, never used again. In both newspaper ads and on the marquee, the name used for SR was "Dolby Spectrasound" (with the full name appearing INSIDE the DOLBY logo box.
Posted by Ken Lackner (Member # 1002) on 06-08-2002, 10:13 AM:
I have always been taught that A and SR are not compatible and that you cannot play an A print in SR and vicy versy. But at my new theater, we play our trailers in A. Why don't they sound as bad as I thought they would?
Posted by Steve Kraus (Member # 476) on 06-08-2002, 10:50 AM:
Both processes are in effect multiple compandors working on different frequency bands. By compandor (compressor - expander) we mean that the sound level variations are compressed on encoding and then expanded again on playback. This keeps everything well above the murk. A simple one processes the entire signal at once which means a high level signal at one frequency will reduce the compression and signals at other frequencies may drop down into the noise. Dolby's invention was to work independently on 4 frequency bands (Type A) and do so in a way that the decoding very acccurately undoes the encoding.
SR does the same thing but more heavily, with more bands, and the frequency ranges can slide a bit as needed depending on the signal. In both cases we are talking about bringing low level signals UP and then putting them back down. Compatibility is going to vary with the material but to some degree playback where low level signals have been raised by SR encoding, then lowered but not all the way by playback in A will result in audio that is still slightly compressed. This can sometimes be an advantage if the listening environment has high background noise. Audio with very wide dynamic range may be hard to hear if the quiet passages are very quiet. This type of playback may leave them a bit louder.As for the specific example of trailers it may also be that trailers tend to be recorded at such high levels that only minimal NR action that is applied. A characteristic of both processes is that high level signals pass through unchanged.
Of course, as we have said elsewhere the SR optical soundtrack is recorded at a lower average level than A (just as A is recorded at a lower level than a typical mono track) so as to trade off a bit of the improved noise level for more range--an extremely loud sound can be that much louder than average dialog level without clipping. So when playing an SR track, a lower level signal, in A-type which is expecting a higher level signal you're automatically reducing the volume a few dB which may be helpful on trailers as well.
Posted by Gordon McLeod (Member # 33) on 06-08-2002, 11:17 AM:
Two other little bits in effect Dolby NR only works on signals below a threshold (Dolby psycoacoustics you only here background noise in quiet parts). Unlike DBX that was a single band that compressed both the high and low level information
Also it does it by adding and subtracting the companded signal from the original to reduce the breathing effects
Posted by Gordon McLeod (Member # 33) on 06-08-2002, 11:19 AM:
Frank the reason was the academy roll off on playback effectively buried the top band where most of the noise reduction action occurs
As such Dolby felt that Mono playback of NR prints was backward compatable
Posted by Steve Guttag (Member # 268) on 06-09-2002, 01:43 AM:
Joe, while one may have to guess, at first, which NR to use on a print in question...it shouldn't take very long to determine which is the correct one! Heck, "knock off" SR cards sound like crap when trying to play back SR too (including the Cat. 222 SR/A). Maybe the only knock-off card that tracks it right is Panastereo's...I haven't listened to it enough to give it a thumbs up or down yet but so far so good.Pay attention to the upper frequencies...how A and SR handles them is quite different. SR has an "spectral skewing" that will make it very bright if played back with A.
Steve K already pointed out that the filters themselves are different in quantity and function.
Again, when in doubt, listen...you should easily be able to tell which one is correct.
Steve
------------------
"Old projectionists never die, they just changeover!"
Posted by Frank Angel (Member # 248) on 06-09-2002, 06:46 AM:
OK, so where do UltraStereo prints come in on this? When you encounter one, what do you use -- Dolby A or SR? UltraStereo prints always sounded unnaturally bright to me -- lots of swishy noise on the top-end -- no matter what format I used.
Posted by Michael Brown (Member # 890) on 06-09-2002, 07:03 AM:
I supposed it the same with DTS prints. But I think Karen allready said the recent ones "Antitrust", "Legally Blond" etc are SR.
Posted by John Pytlak (Member # 331) on 06-09-2002, 07:15 AM:
There's quite a bit of information on the Dolby website:
http://www.dolby.com/company/is.ot.0011.TechOverview.html
http://www.dolby.com/tech/mp.br.0102.EvolutionOfSound.html
http://www.dolby.com/ken/
http://www.dolby.com/tech/ ------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: +1 585 477 5325 Cell: +1 585 781 4036 Fax: +1 585 722 7243
e-mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion
Posted by Gordon McLeod (Member # 33) on 06-09-2002, 09:34 AM:
UltraStereo prints are A type. I believe that Ultra has finally quit doing encoding
Panastereo makes a encoder that does A and SR
Posted by Les Brock (Member # 1041) on 06-09-2002, 03:06 PM:
Paul said "In both newspaper ads and on the marquee, the name used for SR was "Dolby Spectrasound" (with the full name appearing INSIDE the DOLBY logo box."
The correct title is Dolby Spectral Recording hence the Dolby SR.
With the introduction of Dolby Digital the format name SR-D came from Spectral Recording Digital.
Posted by Paul Linfesty (Member # 214) on 06-09-2002, 07:19 PM:
Yes, starting with ROBOCOP in 1987. But that wasn't the logo design used for STAR TREK IV in 1986 in LA.I'm not saying it wasn't technically known as Dolby SR earlier, just that it wasn't the public name used for it at the time, at least not for this title.
Posted by Manny Knowles (Member # 1171) on 06-09-2002, 07:52 PM:
Please tell me more about the Cat. 222 SR/A card and the particular reason(s) why it has such a bad rap. I've even heard of these being referred to as "Dolby Lite." I have these cards in my CP-45's right now and I would like to know if there is a better card I should be using in them for SR NR? I didn't even know there was an alternative to the NR card it came with.While I'm asking...What benefits would I reap from by upgrading from a CP-45 to a CP-65?
Posted by Gordon McLeod (Member # 33) on 06-09-2002, 10:11 PM:
No the 222SR/a is the only card that will work in the cp45
They have less headroom and are not as well performing as the 280T 300 and 350 cards
Posted by Frank Angel (Member # 248) on 06-10-2002, 10:58 AM:
Smart once made an SR knock-off which they called the Copy-Cat 222, for which Dolby took them to court for patent infringment (patent infringment or not, I thought the name was quite clever). Anyone know how well these perform as opposed to real SR cards? Naturally Smart claimed that they were every bit as good as their Dolby counterpart, but I am sure Dolby will claim something different. We have a pair.I never heard if Smart won the lawsuit.
Posted by Gordon McLeod (Member # 33) on 06-10-2002, 11:09 PM:
I mdon't beleive the copycat 280 was the subject of a lawsuite but I could be wrong The Panastereo SR card was
The copy cat280 is ainteresting hybrid that most of the time works on the major issues that SR introduces on playback but not all of them