GUIDE TO SUPER AUDIO CD
What Is Super Audio CD?
Super Audio CD is one of two high-resolution audio discs on the market.
Super Audio CD is the
high-resolution music release format developed by Sony and Philips to
deliver a new type of digital recording known as DSD —” Direct Stream
Digital. In contrast to PCM digital, DSD is a one bit digital stream
sampled at a very high speed, 2.8 MHz. Absent are the artifacts and the
“digital” sound found in 44.1kHz/16 bit (CD quality) or 24 bit digital
systems. Engineers, artists, and reviewers have described DSD as
sounding very “analog-like.” By sampling the signal with a single bit
converter at a rate over 2.8 Megahertz, DSD offers an extremely wide
dynamic range (over 120dB) and extended frequency response, rivaling or
surpassing the best analog and 96kHz digital recording systems.
An SA-CD is, physically, a DVD disc, but one encoded in DSD. An
SA-CD can hold a stereo mix and a multichannel mix; including a
CD-format stereo mix on a separate layer makes these discs compatible
with all existing CD players. (The separate layer makes it a “hybrid”
SA-CD.)
The three audio streams — stereo DSD, multichannel DSD and CD
— do not have to contain the same program material. In fact, some
labels view the 4.7GB DSD layer as an ideal medium to issue several CDs
worth of stereo recordings on one disc. Theoretically, the SA-CD can
hold 256 minutes of high-resolution stereo; the longest-playing SA-CD
we’ve heard is the Police “Live” at 144 minutes.
The SA-CD layer is accessed on disc players that are specifically
equipped for SA-CD playback. Sony, Philips, Linn, Classe, Marantz,
Accuphase, Denon, Kenwood, Aiwa, and Sharp all make SA-CD/CD and/or
SACD/DVD-Video players; Pioneer, Marantz, Onkyo and Integra all offer
“universal” players for CD, DVD-Audio, DVD-Video and SACD playback. The
list of manufacturers grows daily, as the price range and options
expand, with players now available under $200 (US).
In addition to the benefits of high-resolution and multichannel
sound, the SA-CD technology is extremely secure, with multiple layers
of copy-protection and encryption built into the format.
To summarize, a Super Audio CD is a high-capacity disc
that plays back DSD audio. A variety of production scenarios using
commonly available production gear can be employed to take advantage of
the sonic benefits of DSD and the SA-CD. BUT to issue a SA-CD release,
at some point your audio must become DSD data, and it must be
specifically mastered for the SA-CD format. Mastering for SA-CD release
is done with specialized equipment: recorders, converters, the
mastering workstation, even the tape drive to record the master. This
suite of equipment is found in the studios of major record labels
worldwide and in a handful of commercial mastering labs in the U.S.
DVD-Audio is a new member of the
successful DVD family that brings high-fidelity sound to the format.
DVD is a video-oriented medium that is capable of carrying surround
audio and high-resolution stereo audio; DVD-Audio uses the same disc
with encoding schemes that emphasize the audio elements. It’s a
flexible format that enables the producer to include high-resolution
stereo (up to 192k/24 bit PCM) and 5.1 surround (up to 96k/24 bit PCM).
Because it is an A/V medium, menus and other visual elements become
part of the production equation. DVD Audio players are needed to play
back high-resolution audio on DVD-A discs.
To summarize, DVD-A is a higher-bit rate, multichannel implementation of the PCM digital technology represented by audio CDs.
For the full technical brief on this breakthrough technology. Click Here
SonicStudio offers a graphical presentation of similar information, plus the SA-CD project workflow. Click Here
Single-layer vs. Hybrid release
Most SA-CD titles are hybrid discs (with a DSD layer and a CD
layer), playable on SACD-equipped players and CD players. Sony/Philips
specifically developed the hybrid disc in recognition of the demand by
consumers that the format be backward-compatible. Even as listeners
invest in the SACD/home theater array, they still listen to CDs on
portable players and in cars. The hybrid disc technology makes the
music fully available to the listener in any setting.
The hybrid disc also solves the practical problem of maintaining dual inventory; one release serves many markets.
Because CD technology is not secure and its contents cannot be
protected against piracy, the CD layer of ay hybrid disc is as prone to
theft as any standard CD, even as the SA-CD layer is robustly
protected. If security is themost important consideration, a single
layer disc may be the answer.
To illuminate the marketing aspect of this decision, visit towerrecords.com and view the tags that accompany the hybrid and the single-layer SA-CD releases.
What are the ways to produce for SACD release?
To take advantage of SA-CD’s high resolution, your music should be
recorded and mixed using high resolution systems. There are several
strategies you can consider:
Record using a DSD recorder. This is referred to as “pure DSD” and is popular among audiophile record labels.
There are several recorders and workstations available that record directly in DSD format.
- The Genex 9000 series digital recorders are available with internal converters.
- The
Tascam DS-D98 is an extension of the Tascam DA78 family; it uses
standard DTRS tape for recording 2 channels of DSD, and includes
built-in converters. - The SADiE, Pyramix and Sonoma workstations all record multichannel DSD, with external A/DSD and DSD/A converters.
- Prism, dCS, Meitner and Genex all offer high quality external DSD converters.
All of the gear described here is available to buy or to rent. Airshow
has the DS-D98 and Genex 8500 to play back mixes received from our
clients, a Sony Sonoma, and Prism and Meitner converters.
DSD as a master delivery format
The Producers and Engineers Wing of the Recording Academy released
comprehensive guidelines for digital deliverables in 2003; titled
“Master Delivery Recommendations,” it acknowledges that DSD’s high
resolution is “future-proof,” as source media for a variety of release
media. The P&EE guidelines find DSD is an acceptable delivery
format, even for non-SA-CD releases. You may download a copy of the complete document.
For information on commercial rental of DSD gear, please visit https://www.dmtrentals.com
Record on the equipment of your choice, and then mix to DSD.
High-resolution PCM (24 bit/88 kHz, 96 kHz, 176.4 kHz, or 192 kHz
sampling rates) can be produced on several popular workstations like
ProTools HD, Nuendo, and Digital Performer. Use all of your favorite
hi-res PCM and analog mixing tools, then use a DSD recorder to store
the mixes for SA-CD mastering. The same recorders and converters
described above can be used in this scenario.
Mix to high-resolution PCM or analog (yes, it’s hi-res, too!) and leave the final DSD conversion ’til mastering. High-resolution
PCM recorder options are numerous: high-res multitrack recorders like
the Tascam DA-98HR; or hard disk recorders from Mackie, Radar, Alesis,
Tascam and others. High resolution digital mixes can be delivered to
the mastering studio as WAV, AIFF, or SDII files on CDR, DVD-R, hard
drive, and other formats.
What about DSD production tools?
Studio equipment manufacturers are working to give engineers and
producers the full range of digital production tools they need in the
DSD format. Sony has created modular “building blocks” for eq, i/o,
mixing, etc, which will speed up the process of bringing DSD production
and mastering tools to market.
What about SACD reissues?
Sony Music and Universal Music are making extensive use of SA-CD to
generate new interest in catalog recordings. The high-profile release
of the ABKCO Rolling Stones recordings, “Dark Side of the Moon,” and
the early Dylan catalog have heightened listener —” and label —”
interest. According to one label executive working on them, SA-CD
reissues can be tricky. If it’s a well-known recording, and reissued on
CD already, listeners will come to the SA-CD reissue familiar with a
version that was probably digitally edited or noise reduced. The artist
and label may want to evaluate the DSD-remastered version in comparison
with existing remastered versions to choose an SA-CD reissue that best
represents the music. (If the reissue is significant enough, a test
pressing of a DSD-mastered version and a PCM- mastered version may be
warranted.)
To summarize, for a stereo SA-CD release, the process is
similar to that of a stereo CD release, though using specialized DSD
gear in the process. Options range from end-toend (or “pure”) DSD, to
mixing (digital or analog) to DSD media, to DSD mastering of analog or
digital mixes.
What issues does multichannel audio present?
A compelling reason for listeners to invest in SACD and DVD players is surround.
SA-CD is a wonderful medium to experience surround. The Super Audio CD
can hold both a highresolution 5.1 surround master plus a
high-resolution stereo master of 74 minutes of audio on its SA-CD layer
(in addition to the stereo CD layer of the hybrid disc).
A surround release involves the following steps:
- Record
- Mix to high-res stereo
- Mix to 6
channels (or fewer —” the SACD reissue of Mike Oldfield’s classic
“Tubular Bells” is in 4.0). The options described above for delivery of
high-resolution digital stereo mixes are also appropriate for
delivering multichannel mixes. - Master for stereo
- Master for multichannel
For mastering and editing multichannel audio, DSD workstation
options are the Sony Sonoma, SADiE, and Pyramix. SonicStudio’s will be
available soon.
Additional Resources
Multichannel production is beyond the scope of this brief. There are
many good resources on the topic. The monthly Surround Pro is the
primary publication for the working audio pro. Qualified subscriptions
are free: https://www.surroundpro.com.
Dolby Labs offers an extensive publication, “5.1 Channel Music
Production Guidelines.” Among the useful topics covered in detail are
the Center and LFE channels, monitors and subwoofers, delay and bass
management. Dolby offers forms for documenting multichannel sessions.
You may download a copy of Issue 2 at https://www.dolby.com/tech/MultichannelMusicMixing.pdf
Bobby Owsinski of Surround Associates has written and taught extensively on the topic, and offers an instructional DVD: https://www.surroundassociates.com.
Rich Tozzoli is another prolific writer and active surround mixer. His site is https://www.333entertainment.com.
Oliver Masciarotte offers an excellent reading list and comprehensive production resource links in his Info Annex: https://www.seneschal.net.
[Reprinted with permission from Airshow Mastering www.airshowmastering.com]
Airshow Mastering has been in the forefront of studios working
with SACD technology. Since 1999, Airshow has beta-tested workstations
and other production gear, and mastered many of the first commercial
releases in the format. Drawing upon our five years of experience and
compiling up-tothe-minute information, we offer this guide to others
ready to work in this new medium. airshow mastering©2003,2004
