DTS vs. SDDS
Jacob Gunness
(DTS is, to my knowledge, 6 channel digital). It seems that only Sony-
owned Columbia uses SDDS. I heard both systems (DTS in "Jurassic Park" and
SDDS in "Last Action Hero"). SDDS seemed very impressive in comparison
- but then again, Universal throws DTS into just about anything these days
("Beethoven's 2nd"???)
- Jacob Gunness
Eric G. Carter
jg...@diku.dk (Jacob Gunness) wrote:
Universal releases ALL of its films (beginning with JURASSIC
PARK) in the DTS format, which is a 6-channel digital format.
A dual CD-ROM unit (Toshiba 3401 drives are the current model)
carries the soundtrack information which is synchronized with
the timecode printed on the 35mm print. Sony's SDDS, which is
still only in prototype stage in theatres (production units
should be arriving in the next month or so) prints all of the
digital soundtrack data on the 35mm print. The data is highly
compressed (as is Dolby SR-D Digital), but Sony offers up to 8
tracks of sound. (Left, Left Extra, Center, Right Extra,
Right, Subwoofer, left rear and right rear...HOT!). All
Columbia and TriStar releases will be offered in SDDS beginning
this summer. They are also using DTS on some releases (CITY
SLICKERS II, for example).
Eric Carter "The truth shall make you strange"
Ford Prefect
>jg...@diku.dk (Jacob Gunness) wrote:
I must add that DTS costs only $3,750 while SDDS costs around $60,000. WHOA
Also, since SDDS is on the print it is subject to getting torn or interupted
easily. They've managed to sqeaze the digital soundtrak in between the analog
soundtrack and the sprocket holes! This is a very small area to read. DTS
on the other hand, being a dual system, will not be interupeted and is also
highly compressed a max of 3 1/3 hours playing time.
About the only film company using SDDS is Colombia (owned by sony :) ) The
"WOLF" movie is the only one that I know of that is being released this summer
in SDDS (not for sure if any others). Whereas all the film companies are
jumping on the DTS bandwagon. SPEED which opens this friday will be in DTS.
Bradley Kent
David Meek
but one reason that so many theatres "jumped on the DTS bandwagon" was
Jurassic Park. Without that film, DTS would just now be entering mass usage.
Also, it should be mentioned that although DTS is cheaper than SDDS or
Dolby SR-D, DTS does suffer from one technical weakness, compared to the
Dolby Digital system. When DTS (for whatever reason) is unable to maintain
the digital playback, it reverts to a Dolby A-type analog soundtrack. (It's
not true Dolby A, but a similar proprietary & compatable format.) However,
when the Dolby Digital system must revert to analog, it reverts to a Dolby SR
analog track, which has a dynamic range *greater than* that of 16-bit digital!
So, when such digital dropouts occur (not likely in first release...but, quite
possible in older prints), Dolby SR-D has an inherent advantage. But, it's
not likely that theatre owners would be willing to pay the difference for
technical superiority that might never be used.
--
---David Meek--...@jove.acs.unt.edu----U. of North Texas----Denton, Texas---
***PGP 2.6 Public Key on request***
Cal Lott
Since the FAQ has extensive info on all three of the competing
digital formats under discussion here, it seemed appropriate to
re-post it here. I sent a copy of this to the originator of the thread
a few weeks ago.
Enjoy!
Regards,
-Cal
----- Begin included text -----
-----------------------------
Movie Sound Systems FAQ 1.2.0
-----------------------------
Ok, ok, so it's not really a FAQ.
It's not organized in the classic Usenet FAQ style, but it can
undoubtedly answer many questions that you might have about sound in
the movies. This document contains a wealth of information on motion
picture sound, including a fairly extensive glossary of terms. It is
one of the most up-to-date and comprehensive documents available
anywhere, and represents the efforts and contributions of many people
on Usenet and elsewhere.
Your corrections, suggestions, and additions are quite
welcome. Please send email to me, Cal Lott <c...@gsbux1.uchicago.edu>.
I am the keeper of this FAQ and I would love to hear from you.
In particular, I am avidly looking for contributions in the
following areas:
- hard information on Ultra Stereo and any other
Dolby-compatible processes, either current or historical
- information that would allow me to develop a list of films
that were movie sound "firsts", such as the first stereo
film, first film to use Dolby noise reduction, etc.
- information on what format the master sound mixes for a film
are recorded on. (My best guess is L1 or L2 digital tape,
but I could be wrong.)
- anything else you think should be in here but isn't
For those of you who have seen the FAQ before, the jargon
glossary hasn't changed a great deal. The two most substantive changes
are in section 1.0, where I rewrote the scattered notes I had as prose
and expanded the section a bit, and in Section 2.0, which did not
exist in previous versions of the FAQ.
I also plan to add a section on the politics and history of
the current competition between the three new digital sound formats in
the future.
In any case, I think it's improved from the last version, and
I hope that you enjoy it!
-------------------------------------
1.0 How movie soundtracks are produced
-------------------------------------
The creation of a motion picture soundtrack usually takes
place in post-production, after all of the principal photography for
the film is complete. Soundtracks are literally cobbled together one
sound at a time. Here are some of the many types of sounds that could
be put in a film's soundtrack:
- "Canned" sounds from a library:
Many motion picture studios have developed extensive libraries
of various sounds that they use and have used in their films.
These can be quite a mixed bag -- they can be stereo or mono,
recorded on digital, analog, magnetic tape, optical or other
media, and have varying degrees of fidelity.
- On-location sounds:
These are sounds recorded at the actual location of principal
photography, whether on-stage at a movie lot or on-location.
It can be difficult to get usable dialogue or other sounds
at time of filming, especially on-location. Ambient sound
such as honking horns or shouting people or even the noises of
the film crew itself can obscure dialogue or otherwise produce
an effect that the director does not want in the sound of the
film. Outdoor locations can be especially difficult due to the
very limited control the film-makers have of the environment.
- "Looped" or re-recorded dialogue:
If the on-location dialogue is not satisfactory, (or has not
been recorded in the first place,) actors will sometimes
return to a sound studio and lip-sync their dialogue.
- Foley sounds:
A foley artist is a person who specializes in creating sound
effects for film, TV, radio, or even live stage plays. A foley
is a noise or effect that sounds actual, but is not. For
instance, a foley artist might "walk" a couple of shoes down a
wooden board with his hands to produce footstep sounds, or he
might shake a giant sheet of suspended paper to create a
thunder sound.
- Music:
Orchestral scores that are specifically created for a film are
often recorded as the conductor and orchestra view the actual
film footage, in much the same way that an actor looping
dialogue views footage in order to co-ordinate the sound with
the action on-screen. Pre-recorded music not specifically
created for the film might also be mixed in to the soundtrack.
As you can see, mixing in all of these different sounds can be
quite complicated, but that's not all there is to mixing a motion
picture soundtrack.
All of the sound for the film goes into various "stems", which
are basically recorded groups of sounds that are used to make the
soundtrack masters. Each release format (Dolby Stereo, Dolby Stereo
SR, 70mm, and digital) has different characteristics and limitations,
and a master is optimized and made for each format that the film will
be released in.
All modern films get at least one mix in Dolby Stereo (or a
different, but Dolby-compatible process.) If the film is a getting a
"premiere" engagement in various 70mm venues, a separate mix is made
for the handful 70mm prints that will be released. Then, if the film
is also being released in one of the digital formats (DTS, DSD, or
SDDS,) a separate mix will be made for that format, as well.
(As far as I know, all of the modern master mixes are put onto
L1 or L2 digital tape. Since I don't know for sure, I would appreciate
more information on this subject.)
Here is a capsule summary of the various film sound systems'
capabilities, each of which have to be taken into account when the
individual soundtrack masters are made:
- Optical 35mm soundtracks have compressed dynamic range, and
are stereo-only. (They can be Dolby-encoded stereo, of
course.) Nearly all of these soundtracks will be in Dolby
Stereo or a similar process.
- 70mm mag stripe is basically a straight copy of the stem
elements. Dynamic range and fidelity are extremely good.
- The various digital delivery systems (Dolby Stereo Digital,
DTS, Sony SDDS) are also copies of the stem elements, but
apply various methods of lossy encoding. (See individual
entries below for more information.) There is little to no
compression of dynamic range.
Some people have taken issue with my description of the
various digital surround systems as "lossy" systems, correctly
pointing out that the fidelity of these systems exceeds that of all
others with the possible exception of 70mm mag stripe. I do not call
them "lossy" systems because I think that their fidelity is low, but
rather because the digital soundtrack eventually placed on the print
does not contain all of the information present in the original stem
elements due to the perceptual encoding algorithms used in every
current discrete digital format. As for the fidelity of each of these
digital systems, each system can and will stand on its own merits.
------------------------------------
2.0 About first-run movie exhibition
------------------------------------
You may not realize it, but a major war is taking place in the
motion picture industry -- three digital sound formats are competing
for the attention and dollars of producers, exhibitors, and movie
patrons across America.
If you have not seen a movie in one of the new digital sound
formats, you should make the effort. Properly executed, they are far,
far better than plain Dolby Stereo and can add a great deal to the
presentation.
If your local theaters don't have digital sound systems
installed, what can you, as a regular movie patron, do about it? If
you are interested in this and in learning more about the business of
showing first-run feature films, read on.
First of all, know this: your local first-run movie theater is
not in the business of showing movies -- they are in the business of
selling concession items, especially popcorn and soda. The simple fact
is that a movie theater cannot make a profit from ticket sales alone,
because they receive an extremely small percentage of that money.
Theater chains in local areas bid individually on each film.
What they bid is always a percentage of *gross* box office receipts
for a certain amount of weeks. For instance, a big blockbuster will
usually get 99% of receipts for several weeks, and then drop into a
40-60% range soon after. Since films usually take the majority of
their total box office in the first few weeks of exhibition, the
distribution companies and studios wind up with the vast majority of
box office money, and the chains are forced to sell popcorn and soda
in order to turn a profit and stay in business.
The local first-run theater chains are therefore interested
only in a high quality of theatrical exhibition only if it will get
more people into the theater to buy popcorn. This is not to say that
theaters don't want to show good films with a high quality of
presentation, just that the quality of the presentation and of the
film being shown only has an indirect effect on their bread and
butter, which is concession sales.
In addition, the quality of training given to theatrical
management and staff varies a great deal. The cold, hard fact of the
matter is that turnover is extremely high in the industry -- as much
as 80-90% of the staff at a local theater will no longer be working
there in one or two years. It is very much like a job at a fast food
restaurant. Technical knowledge among the floor staff is therefore
extremely low. They are trained to be as courteous as possible to the
customers and to call a manager if a there is a serious problem.
As for management, the situation can be different. Some chains
train their managers fairly well in technical areas, but others have
much less knowledge. Managers are generally trained run the theater in
the most efficient and courteous way possible, with an emphasis on
making sure that the customer does not have to wait too long in the
concession lines. (For obvious economic reasons.) The most prized
theater managers are the ones who can bring in the most concessions
receipts while using the least amount of floor staff possible. (Floor
staff, even though they usually make minimum wage or slightly above,
are by far the most costly overhead for a local theater or chain.)
Projectionists were formerly highly unionized and enjoyed a
great deal of experience and knowledge. Union projectionists are still
around in some areas, but their ranks are thinning due to economic
pressures and due to the greater automation of projection booths and
equipment. Many people feel that the quality of film projection is
fading slowly but surely as the union projectionists are replaced with
less well-trained, non-union projectionists (who make 1/2 or 1/3 as
much per hour as their union counterparts). For certain times of the
week and in certain theaters, managers or even floor staff might be
projecting the film at your local theater.
As you can see, a typical first-run theater can be a total
vacuum of technical knowledge. Managers and floor staff are generally
trained to get as many patrons as possible through the theater and to
sell them as much popcorn an soda as they possibly can. Concomitantly,
their knowledge and concern about technical issues such as sound
reproduction can be very, very low.
Local managers typically have zero influence on the quality of
the equipment used in the theater. If you tell them that they need to
upgrade to one of the new digital sound systems, they will be very
sympathetic but will be unable to do jack squat about it. What you
should do is ask for the address and/or phone number of their
superior. If you want to complain about the poor quality of their
sound system, tell them that you do not blame them personally for the
poor equipment, and that you would like to write a letter to their
superior hoping that it will help to force an upgrade.
Letters written to the local division office of a theater
chain generally get taken very seriously, as long as the letter is
coherent and reasonably polite. Letters or complaint and/or
commendation can also be a very good way to get free passes to future
shows. (The theater chains are not reluctant to give away free passes,
as they get so little of the box office in the first place.)
For maximum impact, mention in your letter that you don't see
why you should pay $7.00 for a non-digital presentation when you can
easily drive an extra fifteen minutes to patronize a competitor's
theater that happens to be exhibiting that feature at the same price,
only in DTS or another digital sound system. The film exhibition
business is often quite competitive nowadays, especially in the larger
markets. Encourage your friends to write similar letters and you
could collectively have an impact.
And remember to be courteous, both in the letter and to the
management and staff of your local theater. They are usually making
every effort to be courteous to you and would like nothing more than
to knock your socks off with a high-impact, top-notch sound system.
Just remember the circumstances that they are laboring under and the
possible scope of their actions.
----------------------------------------------------------
3.0 Matrix versus discrete surround sound: A short history
----------------------------------------------------------
First, here is an interesting reply from Peter Reiher on the
very early history of movies with sound:
----- Begin included text -----
Date: Tue, 25 Jan 94 08:05:54 -0800
From: Peter Reiher <rei...@ficus.cs.ucla.edu>
In message <940125001...@gsbux1.uchicago.edu> Cal writes:
>
> Thanks for the reply. I was specifically hoping that you would
>compose a response, especially to the historical questions.
Here's a little more detailed information I looked up last night.
In the narrowest sense of the term, the first talking movie was
probably a test film W. K. Laurie Dickson showed to Thomas Edison as a
demonstration of the Kinetophonograph in 1889. Edison had assigned
Dickson to work on this at the same time Edison started development of
the Kinetograph. Amazingly, I believe that this bit of sound film
still exists. It's basically an Edison employee saying hello to
Edison from the screen, and saying a few other fairly trite things.
This system was a sound-on-disk system - essentially a Gramaphone
hooked up to a Kinetograph, with presumably some synchronization system.
The Kinetophonograph was deployed in some peep show parlors. Later,
another system using sound-on-disk was deployed into a few theaters.
A fire in Edison's labs in 1914 forever ended their experiments with
sound films, which were never commercially successful.
In 1904, a former Edison employee named Lauste developed a sound-on-
film system. It was not practical for use in theaters due to problems
with amplification. Amplification was actually the problem that kept
sound out of theaters for many years, rather than lack of technology
to match some form of sound with images.
Lee De Forest developed the solution in 1923, with the Phonofilm
system, a sound-on-film system. There were a number of experiments
with this system in the mid-20's, and eventually it was incorporated
into the Fox Movietone system. I believe D. W. Griffith used this
system to film a sound introduction to one of his films, "Dream Street".
In the introduction, Griffith himself stuffily addressed the audience
about the importance of the film in rather pretentious terms. The sound
of this exists, but not, I think, in its original format.
The first major commercial film with synchronized sound was "Don Juan",
in 1926. It used the Vitaphone, a sound-on-disk system. "The Jazz
Singer" was produced (by Warner Brothers, who'd also done "Don Juan")
in the same system in 1927. "Don Juan" had simply had a synchronized
score and some sound effects. "The Jazz Singer" had several musical
numbers and a handful of lines ad-libbed by Al Jolson. (For those who
tend to forget that movies are almost universally written, these ad-
libbed lines are among the few lines of significant dialog ever in the
history of fictional film that can be properly attributed to the actor
speaking it - with the exception of performers who wrote their own
scripts, like Woody Allen and Mae West.) By 1930, sound-on-disk had
been entirely replaced by various sound-on-film systems. Sound-on-disk
was totally abandoned until very recently - I believe one of the
current competing digital systems is sound-on-disk. It has the
advantage of being cheaper and requiring less equipment. It has the
disadvantage that you have to ship disks around, as well as film reels,
and presumably there's room for operator error in matching the wrong
disk to a reel.
Sound-on-film systems used one of two competing technologies. One was
variable-area soundtrack, and the other variable-density. Both used
a portion of the film not projected, out towards the sprocket holes.
Variable-area soundtracks fill a varying area of this part of the film
stock with solid black, encoding both pitch and volume information.
Variable-density instead fills the entire area with varying shades of
grey to encode the information. Both existed in the 30's, but I
believe variable-area eventually prevailed. There were a variety of
sub-schemes for variable-area encoding - fill from one side, fill from
both sides, fill from the center in one or both directions, etc. They
actually did have advantages, but I don't understand them well enough
to explain them.
Peter Reiher
----- End included text -----
[I plan to put in a section here that will basically take the
reader from the introduction of stereo to modern surround sound. I
would like to include a list of film "firsts" along with the year of
the film's release, such as the first stereo film, the first to use
Dolby noise-reduction, etc. I don't yet have the necessary info
complete this yet and would appreciate replies on it.]
Matrix refers to a way of deriving surround information
from only two channels of information. Dolby and Dolby-compatible
systems are the only matrix surround encoding game in town nowadays
and basically came in around the time of STAR WARS. ('77) For more
info on surround sound, go read Bob Niland's excellent LD FAQ.
(#3 -- I'll put in how to obtain it.)
Around the time of RETURN OF THE JEDI (82-83), Lucasfilm
contracted an audio engineer named Tomlinson Holman to supervise
the design of a mixdown theater/studio at Skywalker Ranch to do the
sound production for JEDI. This was the genesis for the THX program,
which now includes the Theater Alignment Program. TAP periodically
inspects theaters to ensure that they are up to high standards of
audio and visual reproduction. Inspection is every six to twelve
months, and theaters that are up to spec get to use a THX-supplied
crossover and run the now-famous "Deep Note" trailer with the "THX:
The Audience Is Listening" logo. (For more information, please see the
entries below for TAP and THX.)
The 90's have seen the rapid entry of the lossy-encoded
discrete-channel digital delivery systems, which seem to be the wave
of the future. For the first time, 35mm sound can equal (and some say
surpass) 70mm mag stripe sound.
-----------------------------------------------
4.0 Jargon (A Concise Dictionary of Film Sound)
-----------------------------------------------
70mm -- For many years, 70mm offered the best sound quality along with
the best picture quality. This higher quality was due to the
fact that the 70mm film stock is large enough to accommodate
six magnetic tracks, which made it the first discrete surround
sound delivery system. 70mm film is more expensive to produce
and exhibit than 35mm, so it was never widespread due to
economic reasons. Historically, the six channels included five
(!) behind the screen (LE/L/C/R/RE or alternately L/LC/C/RC/R)
and a mono surround. Modern 70mm soundtracks use a more
standard channel distribution, however: (L/C/R/LS/RS/Boom).
The current 70mm format uses the channels originally reserved
for LE & RE (Left Extra and Right Extra), and mono surround to
reproduce LS, RS, and Sub, respectively. The advent of
discrete 5.1 channel digital sound for 35mm film is widely
expected to further decrease the number of 70mm releases.
"A" playback chain -- One of two parts of a theater sound system. Its
counterpart is the "B" chain. (see entry) The A-chain refers
to the system that reads the sound information off of the
recording medium (usually the film itself, although DTS uses a
separate CD-ROM) and outputs a line-level signal of some sort.
AC-3 -- Dolby Lab's lossy digital encoding scheme. It compresses five
full range channels and one subwoofer channel with limited
frequency response into 64 to 640 kbits/sec of digital
information. AC-3 has been selected as the official surround
sound system for HDTV, and is starting to show up in some NTSC
laserdisc prototype systems. (Pioneer demoed such a system at
the Jan '94 Consumer Electronics Show.) Dolby Stereo Digital
and the forthcoming Dolby Surround Digital use AC-3.
"B" playback chain -- One of two parts of a theater sound system. Its
counterpart is the "A" chain. (see entry) The B-chain refers
to the amplifier, crossovers, and speakers that accept a line-
level signal from the A-chain and then amplify and route it to
produce audible sound.
Boom Channel -- A nickname for the subwoofer channel. So-called
because it is often used to accentuate explosions, gun blasts,
and other special effects.
CDS (Cinema Digital Sound) -- One of the very early digital delivery
systems, put out by Kodak. TERMINATOR 2: JUDGEMENT DAY was the
major film released in this format. (A very select number of
people got to see T2 in a 70mm CDS presentation and were
reportedly "blown out of the auditorium".) It never saw wide
distribution due to a variety of factors, especially due to
the fact that there were no backups to the digital sound
tracks. (If they failed, the theater went completely silent!)
This system is now defunct.
Dolby -- The last name of Ray Dolby, audio engineer and founder of
Dolby Laboratories. Dolby Labs has made a name for itself in
the audio industry with noise reduction and surround sound
technologies. If a movie is said to be "in Dolby", it usually
means that its stereo soundtrack has been Dolby-encoded for
matrixed surround sound.
Dolby Digital -- (see Dolby Stereo Digital)
Dolby SR -- Short for Dolby Spectral Recording. (see entry under Dolby
Stereo SR.
Dolby SR-D -- This designation is shorthand for a film that has the
best quality digital and analog soundtracks that Dolby can
offer. For a print to be a Dolby SR-D print, it must have
both a Dolby Stereo Digital digital soundtrack and a Dolby
Stereo SR analog soundtrack. (see respective entries)
Dolby Stereo -- This Dolby's term for the process of creating a Dolby
encoded stereo soundtrack and putting it on the optical
soundtracks of a 35mm film. It is more than just putting the
Dolby matrix encoding in the soundtrack -- the Dolby Stereo
process also employs noise reduction (Dolby A or Dolby SR) and
other film-specific processes intended to optimize the
soundtrack for presentation in a theater on film. Nearly all
modern film soundtracks (at least in America) use Dolby Stereo
or a similar process on their films. (see also Ultra Stereo)
Dolby Stereo Digital -- The Dolby Labs digital sound system. It uses
the AC-3 compression scheme, which stores the 5.1 channels in
a 320 kbit/sec digital information stream. This information is
stored in between the sprocket holes of the 35mm projection
print. The Dolby Digital trailer is a spectral steam engine,
and is widely considered to be the most impressive of the
four systems. Dolby recently cut the price of a Dolby Digital
theater system in order to be more price competitive with
their main competitor, DTS. (see entry)
Dolby Stereo SR -- Short for Dolby Stereo Spectral Recording. The SR
process is the latest, greatest way that Dolby has for
squeezing maximum fidelity out of 35mm optical stereo
soundtracks. It squeezes in extra dynamic range (~3dB) and
uses more advanced noise reduction than plain Dolby Stereo.
Dolby Surround -- This is Dolby's name for their home consumer
surround technology. Plain Dolby and Dolby Pro-Logic are ways
of decoding the matrixed surround sound found in the stereo
soundtracks of movies on VCR or laserdisc. (For more
information on Dolby Surround in the home video setting, see
Bob Niland's excellent FAQ on it -- #3 in the series of
laserdisc faqs.)
Dolby Surround Digital -- Dolby's name for their forthcoming digital
sound system for consumers. It parallels Dolby Stereo Digital
in that it is a 5.1 channel system (L/C/R/Ls/Rs/Boom), and
uses the AC-3 encoding algorithm. (see respective entries)
The HDTV alliance recently approved a 384kbps variant of Dolby
Surround Digital for use in their forthcoming standard.
DTS (Digital Theater Sound) -- One of the two main discrete digital
5.1 channel systems currently in use. It is unique in that the
encoded digital information is stored on a CD-ROM, and synced
to the 35mm print via imprinted timecodes. The optical analog
track is kept as a backup. (As an interesting addendum, these
analog optical backup tracks are not Dolby Stereo, but a
proprietary DTS matrixed surround format that is Dolby-
compatible.) The company behind DTS is <xxxxxx>, the principal
manufacturers of the optical soundtrack pickups found on many
35mm projectors currently in use today. DTS got a big rollout
in the summer of '93 for the Spielberg mega-blockbuster
JURASSIC PARK, released by Universal. Universal was reportedly
so pleased with the response that they committed to producing
all future releases in DTS. (DTS had some quality control
problems when they first released the system into theaters
that had only four-channel capability and used old B chain
equipment for playback. The DTS trailer was encoded with
analog as well as digital sound, and some non-DTS theaters did
not snip the trailer as they should have. Many people thought
that they were seeing full-bore DTS-6 (discrete six-channel
L/C/R/Boom/LS/RS) when in fact they were seeing inferior four-
channel DTS-S or even old optical matrixed surround! DTS
quickly realized these problems, and will upgrade all DTS
installations to DTS-6, and encode their trailer with only
digital sound -- no analog.) The DTS trailer is a bunch of
motes that whirl around and coalesce into the DTS logo. (Not
nearly as cool as the Dolby Digital train, IMO.)
Sensurround -- A short-lived system in the early seventies that
delivered thunderous low-frequency rumbles at selected points
during a film by playing low-frequency pink noise through lots
of woofers located about the theater. The four known
Sensurround releases were EARTHQUAKE, MIDWAY, BATTLESTAR
GALACTICA, and ROLLERCOASTER.
SDDS (Sony Dynamic Digital Sound) -- (thanks to Alan Jay, alanj@
ibmpcug.co.uk) Another entry in the discrete digital format
horse race, along with DTS and Dolby Digital. (see entries)
This system uses ATRAC-style lossy encoding on a digital
soundtrack that can be encoded and played back with 8 (L/LC/
RC/R/Boom/LS/RS), 6 or 5.1 (L/C/R/Boom/RS/LS), or 4 (LF/RF/
LS/RS) channels, all discrete. The digital information is
stored between the sprocket holes on *both* sides of the 35mm
film print, and keeps the optical analog track as a backup.
TAP -- Short for the Lucasfilm THX Theater Alignment Program. This is
the division of Lucasfilm THX that provides various services
for for the film industry, including supervision of feature
film releases by Lucasfilm on behalf of the studio. These
services include (1) print and reel by reel review, (2)
technical assistance in the alignment and calibration of
theater A and B playback chains, and (3) evaluation of actual
theatrical presentations in theaters (print condition, sound,
theater services, etc.)
THX -- A Lucasfilm quality-control program that is dedicated to
maintaining a high standard of visual and audio quality in
theatrical presentations. (And now video and home theater as
well, but that's another story.) The THX Theater Alignment
Program conducts periodic inspections of theaters and certifies
them if they meet certain standards. (Also see TAP entry above.)
Certified theaters get to run the cool "Deep Note" trailer
before their feature presentation.
-------------------------------
Credits (In Alphabetical Order)
-------------------------------
Many, many thanks to all of these people and everybody else who has
contributed to this FAQ. My apologies if I have left you out!
Thanks to:
Ron Higgins <rhig...@carroll1.cc.edu> for forwarding all those non-
Usenet replies to me in the early days of this FAQ, and for
prodding me to get the revisions done. 8-)
Alan Jay <al...@ibmpcug.co.uk> for sharing his excellent article on
the Sony SDDS system.
Michael Lodman <mlo...@procy.gi.com> for technical info on AC-3.
Paul Matiwy <mst...@aol.com> of Lucasfilm THX for information on
THX, 70mm, soundtrack masters, and other miscellaneous stuff.
Peter Reiher <rei...@wells.cs.ucla.edu> for his excellent and
informative essay on the beginnings of sound in the movies.
Steve Thompson <dolb...@aol.com> of Dolby Labs for setting me
straight on Dolby's terminology for their systems.
Mark Vita <vi...@gloucester.dab.ge.com> for sharing his DTS info.
I highly recommend Widescreen Review to those people that have an
interest in movie sound and in high-quality video reproduction in
their own home. It's terribly hard to find on newsstands -- email me
if you would like subscription information.
---------------
Version History
---------------
1.0.0 1/94 Proto-FAQ. A sketchy, basic outline. First posted to
Usenet on 1/18/94 for additions and corrections.
1.0.1 1/94 Added a few new Dolby entries, and A-chain and B-chain
entries. Never posted to Usenet.
1.1.0 3/94 Various and sundry major revisions throughout. Release
date on 3/9/94.
1.1.1 4/94 Some text correction and other minor clean-ups.
1.2.0 5/25 Section 1.0 expanded, and Section 2.0, "About first-run
movie exhibition" added. Released on 5/27/94.
----------------
Copyright Notice
----------------
This document is copyright 1994 by Cal Lott. Rights for unlimited non-
commercial use of this document, including retransmission over Usenet
and other computer networks is expressly permitted, provided that
this document is transmitted in its entirety, including this notice.
All other rights are expressly reserved.
----- End included text -----
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