Film-Tech Forum ARCHIVE: What is Dolby SR anyway?

This is topic What is Dolby SR anyway? in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Ravindra Desai (Member # 2337) on 04-08-2004, 11:36 AM:

Is it an optical noise reduction technology or anything else?
If you were to compare sound with and without SR card, what are the differences that you notice?

Ravindra.

Posted by Gordon McLeod (Member # 33) on 04-08-2004, 11:54 AM:

Do a search Noise reduction has been discussed many times before and need not be restarted

Posted by John Pytlak (Member # 331) on 04-08-2004, 12:15 PM:

Some links:

http://dolbysearch.dolby.com/tech/mp.br.0102.EvolutionOfSound.html

quote:
The next step: Dolby SR
In 1986, Dolby Laboratories introduced a new professional recording process called Dolby SR (spectral recording). Like Dolby noise reduction, it was a mirror-image, encode-decode system used both when a soundtrack is recorded and when it is played back. It provided more than twice the noise reduction of Dolby A-type, and, moreover, permitted loud sounds with wider frequency response and lower distortion.
The 35 mm optical soundtracks treated with Dolby SR instead of Dolby A-type not only sounded superb in cinemas equipped with new SR processors, but also played back satisfactorily in all cinemas. This led to the situation today, whereby the analog soundtracks on virtually all prints are Dolby SR tracks.

http://dolbysearch.dolby.com/ken/

quote:
An Introduction to Noise Reduction
Table of Contents

Part I: Noise Modulation
Part II: The Ideal Noise Reduction System
Part III: Dynamics of Noise Reduction Systems
Part IV: Compression and Expansion Curves
Part V: More on Compression and Expansion Curves
Part VI: Realizing the Bilinear Compression Characteristic
Part VII: Putting It Together
Part VIII: The Sliding Band
Part IX: Action Substitution

http://dolbysearch.dolby.com/company/is.ot.0011.TechOverview.html

quote:
Overview of Dolby Technologies

Introduction
Analog Recording Technologies
A-type NR
B-type NR
C-type NR
Spectral Recording (SR)
S-type NR
HX Pro
Digital Audio Coding
AC-1
AC-2
Dolby Digital (AC-3)
Dolby E
MLP Lossless
AAC
Film Sound
Dolby Stereo
Dolby SR
Dolby Digital
Dolby Digital Surround EX

Posted by Patrick de Groot (Member # 858) on 04-08-2004, 04:48 PM:

Soldere a custom cable where on one end you have some plugs that fit into your Dolby pre-amp test points in the CP (L, R, grounding) and on the other end a plug where you can input a headphone or input it to the non-sync of the dolby CP.
That way you can listen to the audio that exits the pre-amp.
Dolby SR increases the sound quality a lot (dynamic range)!

Posted by Bobby Henderson (Member # 840) on 04-08-2004, 05:34 PM:

Dolby SR is one of the elements in the best quality magnetic analog recordings. It allows more headroom than standard 16-bit LPCM (+/-22db for Dolby SR magnetic versus +/-20db for 16-bit LPCM). 70mm Dolby SR magnetic was an impressive sound format, certainly every bit as good in terms of quality (if not a bit better) than any of the current 35mm digital systems.

Posted by Mark Gulbrandsen (Member # 72) on 04-08-2004, 06:08 PM:

A good majority of digital soundtracks on films made today are mastered to the common DTS, SRD, and SDDS digital formats from a 6 TRACK DOLBY SR MAGNETIC MASTER. Thats how good SR actually is!!

Mark

Posted by Mark J. Marshall (Member # 1409) on 04-08-2004, 11:40 PM:

When Dolby first created SR, I remember reading at the time that no one knew how low the analog hiss on an SR recording actually went because they (Dolby) hadn't been able to find a microphone with a lower noise floor than SR.

I also remember that DDD CDs all of a sudden couldn't be counted on for audio quality that was superior to AAD CDs. If the AAD CD was recorded and produced using SR, it could (and a lot of times did) sound better than one that was recorded & produced digitally. I don't buy a lot of CDs anymore, so I'm not sure if this is still the case or not.

[ 04-13-2004, 12:17 AM: Message edited by: Mark J. Marshall ]

Posted by Josh Jones (Member # 447) on 04-10-2004, 05:15 AM:

From another board I hang out on....

STFW...IE seach the fucking web...

pretty basic stuff here.

Josh

PS. I'm not really an asshole, I'm just a bit on the tired side.

Posted by Chris Hipp (Member # 1788) on 04-11-2004, 11:38 PM:

I feel dumb, I was actually about to search STFW.

Posted by Frank Angel (Member # 248) on 04-12-2004, 11:48 AM:

If Ray Dolby continues, there won't be enough letters in the alphabet for his processes. Come to think of it, his format numbers are getting a little out of hand also.

Posted by Bobby Henderson (Member # 840) on 04-12-2004, 05:22 PM:

quote:
If the AAD CD was recorded and produced using SR, it could (and a lot of times did) sound better than one that was recorded & produced digitally.

I agree with that. Some of my music CDs from the late 1980's really sounded incredible, and they were "AAD" or "ADD" in variety. On occaision, Dolby SR would come up in the liner notes on some discs. Pink Floyd's "A Momentary Lapse of Reason" had a good amount of digital recording, but their notes also talk about analog recording being done using Dolby SR and SMPTE timecode.

It's also no surprise that many of the early DVD-A and SACD discs offered from Warner Bros. and Sony were digitized from good quality analog sources. It's just a simple fact a really well done analog audio recording (or analog film photographic recording) will transfer up to newer digital formats more gracefully than an outdated digital format. That's a fact I feel very few of the "D-Cinema" crowd is willing to realize.

Posted by Phil Hill (Member # 371) on 04-12-2004, 11:44 PM:

Josh Said:

quote:
I'm not really an asshole, I'm just a bit on the tired side

I'd hate to think what you would say if you were *really* tired.... [Eek!]

>>> Phil