Super Audio CD - FAQ
August 28, 2009
by Yoeri Geutskens
Also in Hungarian.
Table of Contents
Discs
Audio
Packaging
General
What is SA-CD?
SA-CD is short for Super Audio CD or, if you prefer, Super Audio Compact
Disc - an optical music carrier that may or may not be intended
to succeed the regular audio Compact Disc format introduced in 1983. In short
it is designed to provide better sound quality, both in the form of higher
fidelity and, optionally, in the form of multi-channel (surround) sound, while
maintaining backward compatibility with CD. For more details, read on.
Who invented SA-CD?
SA-CD was developed by Sony and Philips. Who invented what exactly remains
a secret shared between the two companies but is quite irrelevant. The
trademarks are owned by Sony. Philips is the licensor of the disc format
and the trademark.
Is this FAQ officially endorsed by Sony or Philips?
No, but we have run this FAQ against some experts in these companies
to weed out any factual errors and get permission for using their illustrations.
Whence the funny logo? It reminds me
of Jugenstil/Art Nouveau/Science Fiction/Fantasy/Tribal tattoos/Yes typography/<fill
in your own association here>
The logo simply shows SA CD - the S and A in the upper half, the C and
D in the lower half. Presumably the logo is meant to convey a sense of fluid,
organic, natural curves as opposed to the straight, angular shapes of the
Compact Disc Digital Audio logo, representing natural, analogue sound in contrast
to the imperfect digital sound reproduced with the technology of 20 years
earlier. This is however mere speculation.
Why is the acronym often written with a dash in it?
That's to distinguish SA-CD from SACD, la Société des Auteurs et Compositeurs
Dramatiques - a French copyrights body.
What is the Scarlet Book?
Scarlet Book is the name of the official specification of the SA-CD
format.
Why is it called like that?
Traditionally the books containing the format specifications of optical
discs are named after a colour. A lot of names had already
been used: Red Book (Audio CD), Yellow Book (CD-ROM), Orange
Book (Recordable CD), Green Book (CD-interactive), White Book (Video-CD),
Blue Book (Enhanced CD), even Rainbow Book (MiniDisc).
But there's more. Scarlet is not just red - it's a certain
shade of red. Sony and Philips might also have called it the Crimson Book
or Burgundy Book for all we know but it should be seen as a refinement of
the Red Book that defined the original audio CD, often referred
to as RBCD (for Red Book CD) or CD-DA for the official name 'Compact Disc
Digital Audio'.
Technology & Specifications
Discs
What is a hybrid SA-CD?
A hybrid SA-CD is an SA-CD disc that can be played on regular CD players.
The sound quality in that case will, in principle, not be better
than that of a regular CD (though the CD-compatible layer is usually
derived from the high resolution signal with SBM for better sound ... or similar
words). The obvious benefit of a hybrid disc is that you don't need
to replace all your CD players by SA-CD players at once. In fact you
could even start collecting SA-CDs before you own an SA-CD player.
Hybrid SA-CD works in a different way. Both the CD layer and the high-density
layer are 'read' from the same side. The other side has a printed
label, so it is easy to recognize the disc and place it correctly in the tray
of the CD player. How it works? The high-density layer is partly
reflective, partly transparent. At the wavelength used by regular CD layers
(780 nm) the SA-CD layer is invisible so a CD player will just 'see' the CD
layer. At the wavelength used for DVD and SA-CD (650 nm), the SA-CD layer
is reflective.
Are all SA-CDs hybrid?
In the early days of SA-CD,most titles were released as 'single layer'
i.e. SA-CD-only but nowadays virtually all SA-CD releases are
hybrid discs. Currently, more than 90% of the SA-CD catalogue consists of
hybrid discs and this rate continues to rise.
Can I see the difference?
Yes. Single-layer SA-CDs look 'plain silver' while hybrid ones have
a goldish shine to them.
What is the difference between a hybrid SA-CD and a Dual Layer SA-CD?
A hybrid SA-CD consists of a CD and high-density layer while a Dual
Layer SA-CD disc contains two high-density layers, making it incompatible
with CD players. The option of a Dual Layer SA-CD, specified in the SA-CD
standard, is intended to provide more music capacity. Dual Layer SA-CDs
are sometimes used for special surround demo discs or for long classical
works.. They are relatively rare.
Are all SA-CDs multichannel?
No, especially in the beginning many SA-CDs released were stereo only.
Nowadays most SA-CDs released are stereo plus multichannel. Two thirds
of all SA-CD titles are multichannel and the general trend is up.
Is the stereo signal derived from the multichannel signal?
No. Unlike DVD-Audio, the SA-CD format does not support 'down-mixing'.
When an SA-CD contains stereo and multichannel sound, these are stored
separately on the disc.
Do all SA-CDs contain a stereo mix?
Nearly all of them do. There are a few examples of hybrid SA-CDs that
contain a multichannel mix but no stereo mix in the SA-CD layer, even though
the CD layer does contain a stereo mix. Examples are the budget SA-CD series
by Universal's Eloquence label.
Is the content of the 'Red Book' CD and the SA-CD layer the same, apart
from sound quality?
Not necessarily but in practice it generally is. In some cases
you may notice slight variations in playing time.
What is PSP?
PSP is short for Pit Signal Processing - the most prominent copy protection
measure of the SA-CD format. PSP is a physical watermarking feature that
contains a digital watermark modulated in the width of pits on the disc
(whereas data is stored in the length of the pits). The optical pickup
must contain special circuitry to read the PSP watermark, which is then
compared to information on the disc to make sure it's legitimate. Because
DVD-ROM drives use an optical pickup that lacks this specialized watermark
detection circuitry they cannot read the data on the high-density layer
of a protected SA-CD disc.
Pit Signal Processing has nothing to do with PlayStation Portable, another
PSP name coined by Sony.
Audio
What is DSD?
DSD is short for Direct Stream Digital, the way in which the analog
sound signal is described in the digital domain. It was originally invented
by Sony for archiving studios' master tapes with the idea that they shouldn't
be left wondering ten years later why they hadn't used a better encoding
scheme before transferring and discarding these masters.
How does DSD work?
Technical experts will tell you DSD is basically a 1-bit Delta/Sigma
conversion scheme. We'll try explaining it in somewhat more understandable
terms but cannot avoid using some technical terms too.
Basically it works as follows: DSD being a 1-bit signal means that every
bit represents a sample - a measurement of the amplitude of the sound wave
at a certain time. Since a bit can only have two values, every bit in a DSD
stream only tells weather the amplitude of the sound signal was higher or
lower than the previous sample. Because it doesn't tell how much higher or
lower the amplitude is, you can imagine you need a lot of samples to accurately
describe the signal. Well, DSD uses 64 times the sampling frequency of CD:
2.822 MHz vs 44.1 kHz. The factor 64 is not randomly chosen. It's a power
of two, meaning that it's relatively straightforward to upsample from typical
PCM frequencies including 44.1 kHz and multiples like 88.2 kHz.
What is the difference between PCM and DSD?
PCM (Pulse Code Modulation) is a very abstract way to describe an analog
signal in a digital way but it's the best way that existed at the beginning
of the eighties when CD was developed and introduced. In PCM, every sample
consists of a combination of bits (typically between 14 and 24, depending
on the carrier) describing the amplitude of the signal. The number of bits
determines the resolution of how finely the signal can be described, where
every added bit doubles the number of levels that can be distinguished.
Converting from analog sound to PCM and back to analog sound involves
a fair number of processing steps, such as quantization. Every step can cause
further distortions such as quantization noise, which has to be filtered out,
in turn again deteriorating the sound quality.
DSD on the other hand is an extremely simple way of converting from
analog to digital and back. The entire process is extremely transparent.
In fact, the DSD bit stream is so closely related - perhaps
analogous would be a proper term here - to the analog signal that if you were
to feed it to a speaker (as a series of +1 and -1 values) you'd get back audible
music.
Wasn't CD supposed to deliver perfect sound?
Yes, it was and it did represent the state of the art in 1982 - what
could be put into a CD player but also what could be put on a practical,
12-cm optical disc - but technology has progressed and so has insight into
human perception of sound. For instance, it only became apparent later
that although the human ear cannot directly pick up frequencies above 20
kHz they are actually of importance for the way we hear sounds. SA-CD with
DSD extends the frequency range towards 100 kHz.
A possibly more important difference between CD's 44.1 kHz 16-bit PCM
sound quality and SA-CD's 2.8 MHz 1-bit DSD sound quality is the accuracy
in the time domain. As it turns out, the human ear is extremely sensitive
to minute timing differences. In fact, of the various cues our brain uses
to determine the direction of sound sources, probably the most important cue
is the difference in time it takes for a sound to reach our left ear versus
the right ear. With a sampling frequency of CD, 44,100 times per second it's
very difficult to reproduce a good 'sound stage' which is why you may find
that the sound of a CD often 'sticks to the speakers': you'll hear it coming
from the left speaker and from the right speaker but there's nothing in between
- the proverbial 'hole in the middle'. This is an area in which DSD excels.
Furthermore, at 120 dB the dynamic range of SA-CD is much improved
over CD.
Above all, SA-CD provides the option of multichannel sound where Audio
CD only offers stereo. More about that later.
What does it mean when an SA-CD is recorded in PCM?
Although the audio on the high-density layer of an SA-CD is always DSD or
DST, the original recording may have been made using (high-resolution)
PCM technology, which is then converted to DSD for the SA-CD master.
Hence the confusing terms like "24-bit 96 kHz SA-CD". The DSD sample rate
was specifically chosen to allow integer/fractional conversion
from all PCM sample rates.
What is the difference between SA-CD and HDCD?
HDCD (officially an acronym for High-Density Compatible Digital because
the company that conceived this standard could not use a name that included
'Compact Disc') is a variant of the audio CD format that uses some otherwise
unused 'subcode' bits to enhance the resolution slightly. It's an elegant
approach in the sense that it provides the sort of two-way compatibility
with CD like described for hybrid SA-CDs above: HDCDs can be played on
regular CD players as if they were normal CDs: the player will simply ignore
the extra bits.
While it provides an improvement over 'Red Book' CD it doesn't approach
the fidelity of SA-CD, or of DVD-Audio, for that matter.
HDCD was developed by a company called Pacific Microsonics,
later acquired by Microsoft.
What is the difference between SA-CD and DVD-Audio?
Although both aim or aimed to succeed the audio CD as preferred carrier
for music by providing higher fidelity sound and multichannel sound, there
are a number of important differences between the two formats.
- Compatibility - SA-CD provides the option of compatibility with CD
players by means of the hybrid disc (see What is a hybrid
SA-CD? above). While this is an option, in practice all discs
released nowadays are actually hybrid. Hybrid SA-CDs can also
be played on plain vanilla DVD-Video players but only in 'Red
Book' CD quality. DVD-Audio discs (other than Dual Discs) on the other
hand are not compatible with CD players. The format does however mandate
added tracks for compatibility with DVD-Video players. This can be in the
form of Dolby Digital, DTS or high-resolution stereo PCM.
- SA-CD uses DSD audio format while DVD-Audio employs PCM. The difference
between DSD and PCM is explained above (see What is
the difference between PCM and DSD?). Many variations are allowed in
DVD-Audio content: sampling rates can be 48, 96 or 192 kHz; resolutions
can be 16, 20 or 24 bits; the number of channels can go up
to 5.1 - left, right, center, left surround, right surround and LFE (Low
Frequency Effects). The creators of a DVD-Audio title however have to make
a trade-off between these parameters: 5.1 channels at 192 kHz sampling
rate with 24 bits resolution is not possible. A realistic combination for
multichannel sound, for instance, is 96 kHz for the front channels and
48 kHz for the surround channels 24 bits resolution. For more details about
possible combinations refer here: http://en.wikipedia.org/wiki/DVD-Audio#Audio_specifications
- On SA-CD, the multichannel and stereo DSD mixes are stored separately
on the disc. The DVD-Audio standard allows the player to generate
a stereo downmix from the multichannel mix.
- SA-CD supports up to six channels at full bandwidth. Rather surprisingly,
in its current form the SA-CD standard does not specify how
the channels shall be used precisely. Multichannel discs use
3 to 6 channels.
- The SA-CD format permits additional data including text, graphics
and video. In practice however, only the text option is used.
It works similar to CD-Text in the Red Book CD format. While
DVD-Audio is also purely an audio format, the DVD format allows
combination of DVD-Audio and DVD-Video content on the same disc, even on
the same side.
- The catalogue of SA-CD spans over 4,500 titles with, on average,
70 new releases added per month.
Can I hear the difference?
While the difference between regular audio CD and the high-density layer
of SA-CD can be quite easily perceived, even to untrained ears, the sound
difference between SA-CD/DSD on the one hand and DVD-Audio/hi-res PCM on
the other hand will be more subtle.
A few dozen titles have been issued on both formats so if you have a
player that's compatible with both SA-CD and DVD-Audio you can try for yourself.
How does multi-channel sound on SA-CD (and DVD-Audio) differ from surround
sound on DVD-Video?
Dolby Digital and DTS were developed for movie sound effects and are
perfectly tailored for that but less suited for high-fidelity music reproduction.
Both apply lossy compression (much like MP3 does), whereas the DSD signal
used on SA-CD does not. A lossless compression scheme called Meridian Lossless
Packing (MLP) exists for DTS but this cannot be used with the DVD-Video format,
only with DVD-Audio.
Of course, on DVD it's possible to use uncompressed PCM, even in high
resolution up to 24 bit at 96 kHz, but DVD-Video only supports stereo PCM.
Multichannel PCM is limited to the DVD-Audio format.
What about DTS-CD?
DTS-CD is a CD that contains 5.1-channel audio in DTS format (bit rate:
1,378 kbit/s). It does not contain PCM. It can be played on CD players
with an 'SPDIF' digital output and on DVD players, in combination with
an AV receiver that supports DTS decoding. See http://en.wikipedia.org/wiki/5.1_Music_Disc
What is DST?
DST is short for Direct Stream Transfer - a losslessly compressed variant
of DSD. Lossless compression means every single bit from the original input
stream is delivered at the output after decompression, just like a zipped
file on your PC would be reproduced bit by bit, only DST is unzipped on
the fly. DST is used on multichannel SA-CDs .
What is DSD128?
DSD128 is DSD at twice the default sampling rate: 5.6448 MHz. DSD128
is used in some studios for editing. The normal DSD format is also called
DSD64 where confusion is possible.
What is DXD?
DXD is short for Digital eXtreme Definition - a sound encoding scheme
for professional use that was developed for editing high-resolution recordings
because DSD is not ideally suited for editing. DXD is a PCM-like signal
with 24-bit resolution sampled at 352.8 kHz - eight times 44.1 kHz. The
data rate is 11.2896 Mbit/s - four times that of DSD.
What is Direct SBM and what has it got to do with SA-CD?
SBM is short for Super Bit Mapping - one of various methods for down-converting
an audio signal from a higher resolution to a PCM signal with the desired
resolution. It involves techniques known as dithering and noise shaping.
Direct SBM is the method for converting a DSD signal to 16-bit 44.1 kHz
PCM in one step in order to minimize noise because every decimation step
potentially adds quantization noise. On hybrid SA-CDs with the Direct SBM
label, the audio on the CD-compatible layer is derived from the DSD master
using this process.
Will SA-CD and/or DVD-Audio be superseded by Blu-ray Disc or HD-DVD?
No, that isn’t likely to happen. Blu-ray Disc (BD) and HD-DVD are aimed quite squarely at storage of (high-definition) video and secondly on data storage for computers. No audio-only variant of BD has been specified, and as far as we know DSD hasn’t been included in the range of optional audio formats on BD. You may consider SA-CD to be the HD Audio complement to BD.
Both formats work with newer versions of the multichannel audio standards by Dolby and DTS: Dolby TrueHD and DTS-HD offering up to 7.1 channels of audio. Like Dolby Digital and DTS however, these audio formats are primarily designed for use with movies.
Packaging
What is a Super Jewel Box?
A Super Jewel Box is a newer, improved version of the ubiquitous original
jewel case used with the majority of CDs. You can recognize a Super Jewel
Box by it's rounded corners which are less prone to breaking when dropped,
especially the hinges. Another improvement is that it permits visuals on
all six sides, including the top and bottom surfaces. There are three versions:
a compact version, used with SA-CDs, a medium-sized version, used with
DVD-Audio discs and a tall version used with some DVD-Video discs, mostly
music titles.
Are all SA-CDs packaged in Super Jewel Boxes?
No, some SA-CDs are packaged in traditional jewel cases, digipacks or
other forms.
Do Super Jewel Boxes always contain SA-CDs?
No, a Super Jewel Box is certainly no guarantee for an SA-CD, especially
since Universal Music has started using them for many most of their new
releases in 2006.
Practical use
/ Playback equipment
Can I play SA-CDs on my CD player?
Hybrid SA-CDs you can play on every CD player. Only single-layer
SA-CDs cannot be played on regular CD players. See What
is a hybrid SA-CD? above.
Can I play SA-CDs in my car?
Of course if you have a regular car CD player you can play the CD-compatible
layer of hybrid SA-CDs. If you want to enjoy them properly however you'll
need a car SA-CD player. Since Q1 2007, Sony has a range of such players
for the 'aftermarket', including stereo as well as multichannel models.
As of the same quarter, Bose has announced a 'universal media player'
for cars, supporting SA-CD as well as DVD-Audio. This, on the other hand,
is a line-fit model, i.e. factory-installed. Thus far it's only available
in one Ferrari model.
Can I play SA-CDs on my DVD player?
Most DVD players simply recognize (and play) an SA-CD as a CD. A few
early models can be confused because before they spot the CD layer they
detect a DVD layer with content that they can't decode.
Can I play SA-CDs on my HD-DVD or Blu-ray Disc player?
No HD-DVD player with SA-CD support was ever made. SA-CD-compatible Blu-ray Disc players include (the first two generations of) Sony’s PlayStation 3 and certain models from Oppo, Denon, Marantz, McIntosh, Lexicon and Cambridge Audio.
Can I play SA-CDs on my games console?
Hybrid SA-CDs can be played as CDs on all consoles that support ‘Red
Book’ audio CD. The high-density layer will only play on a PlayStation
3. The output is just stereo via the analog AV out. The SPDIF output
is silent during SA-CD playback. Multichannel audio is available only via
HDMI however the signal is not DSD but high-resolution PCM: 24-bit at 176.4,
88.2 or 44.1 kHz (configurable as of firmware version 1.90).
Can I play SA-CDs on my PC?
The SA-CD layer cannot be played in any PC drive - not even in those
Sony VAIO PCs that support DSD audio. The CD-compatible layer of hybrid
SA-CDs can be played but some early CD/DVD drives have difficulties due
to misdetection (mistaking the high-density layer for a DVD). Pure CD-ROM
and CD-R/RW drives that do not support DVD will work reliably.
Can I copy an SA-CD?
Never say never but so far SA-CD's copy protection measures
have not been cracked. Besides, you cannot buy SA-CD recordable discs
nor SA-CD writer drives. Copying the CD-compatible layer of a hybrid SA-CD
will be possible on an audio CD recorder if it is not protected with SCMS.
It may also be possible on PCs; see Can I play SA-CDs
on my PC? above.
Can I record my own SA-CDs?
No. You can neither buy SA-CD blanks nor recorders. Making SA-CDs involves
studio equipment (a process called 'quick mastering') or industrial replication
machines. For more information refer to SonyDADC.com, CrestDigital.com,
Sonopress.com and MediaHyperium.com
Can I output SA-CD audio via digital output?
There are various types of 'digital outputs':
- SPDIF (coaxial or optical digital audio output) is not compatible
with DSD; only with PCM (IEC- 60958) and MPEG2 Multichannel,
Dolby Digital & DTS
(IEC-61937). Reportedly some Sony SA-CD players perform down-conversion
to PCM 88.2 kHz, a sampling rate which is officially not part
of the SPDIF spec but in practice supported by many AV receivers
nowadays.
- i.LINK, also known as FireWire and IEEE1394, is a high-performance serial
bus used for connecting peripherals to multimedia computers.
It can carry DSD audio in a secure way but there are few
devices (SA-CD players and AV receivers) that can handle this.
SA-CD players include Sony’s
SCD-XA9000ES and Yamaha’s DVD-S2500.
- HDMI supports DSD audio from version 1.2 up. PlayStation3 uses version
1.3 of HDMI but thus far it doesn’t provide DSD output. See Can
I play SA-CDs on my games console? above. Players that do include Pioneer’s
DV-600AV and Oppo’s DV-980H.
Are there any amplifiers or AV receivers that accept DSD input?
There are two digital connections that can provide DSD input:
- i.LINK with DSD is not a common feature (yet) but it’s available
on various receivers, including Sony’s STR-DA9000ES, Pioneer’s
VSX-59TXi and VSX-84TXSi, and Yamaha’s RX-Z9.
- HDMI from version 1.2 up supports DSD but although several receivers are compatible with this HDMI version, so far few of them decode DSD. Models that do include Sony’s STR-DA5300ES (called TA-DA5300ES in Japan), Marantz SR60001, SR7001, SR8001, SR7002 and SR8002, Yamaha’s RX-V661, RX-V861, RX-V1700, RX-V2700, RX-V1800, RX-V3800 and RX-Z11 (DSP-AX661, DSP-AX761, DSP-AX861, DSP-AX1700, DSP-AX2700, DSP-AX1800, DSP-AX3800 and DSP-Z11 in some regions), Denon’s AVR-3808 and AVR-4308 and Onkyo’s TX-SR805, TX-SR875 and TX-NR905 receivers.
How many SA-CDs are available?
There are so far about 4,500-5,000 releases worldwide. Some early titles
are no longer available. About 4,000 of these can be ordered
from vendors and third-party sellers linked to www.SA-CD.net.
How do I find out if album X has been released on SA-CD?
Check the database on www.SA-CD.net - it's the most comprehensive list
of SA-CDs on the web.
How many labels support SA-CD i.e. publish music on the format?
At the time of the most recent update 443 labels have released one or
more SA-CDs.
How many brands support SA-CD i.e. make SA-CD players?
The total number we do not know - it keeps growing and some of the manufacturers
are quite esoteric companies that aren't always easy to spot.
Brands
include:
How many models of SA-CD players are currently on the market?
According to estimates by Sony,by June 2007 "the cumulative quantity
of SA-CD hardware delivered to market is around 20 million including PlayStation
3. The number of models available in the market would be now close to 200
from 43 manufactures". We know of no information that contradicts this.
Should I buy a CD/SA-CD player, a CD/SA-CD/DVD-Video player or a 'universal'
CD/SA-CD/DVD-Audio/DVD-Video player?
That's a matter of preference. Advantages of 'universal' players obviously
include compatibility with more media using fewer devices but as a drawback
you may feel the video circuitry distorts the audio. Even if the device offers
the possibility to disable the video circuits you may still feel it's surely
a compromise. In that case, or when you don't object to having multiple devices
for your various media, or if you listen to music and watch movies in different
rooms, a dedicated CD/SA-CD audio player may be your best choice. Otherwise
you'll probably find the combined player more convenient.
Do I need a special receiver/amplifier for connecting an SA-CD player?
In terms of connections: It depends on whether you want to
connect an SA-CD player with multichannel output rather than just stereo.
If so, you'll need a receiver with multichannel input: depending on
the SA-CD player's outputs you may use i.LINK or HDMI (see Are
there any amplifiers or AV receivers that accept DSD input?) but the most
obvious (though not the most convenient) solution is using 6 analog connections.
This is common on all modern AV receivers but truly audiophile amplifiers
in many cases are still stereo.
Concerning fidelity: there are definitely sound quality differences
between receivers but it must be said that even an affordable, mainstream
receiver can let you hear the difference between CD and SA-CD. When
it comes to accuracy in the time domain (see Wasn't CD supposed
to deliver perfect sound?) the receiver is usually not the bottleneck
(nor are the speakers): the carrier is. There are exceptions: some receivers
internally convert analog signals to PCM in order to do processing in the
digital domain. Depending on the design, this may be PCM of RBCD quality:
16-bit resolution and 44.1 or 48 kHz. Of course, the benefit of DSD is lost
then. Some of these receivers allow bypassing these conversion steps (at the
expense of equalizing and other adjustments) but do stay alert.
Do I need special speakers and cables for SA-CD?
Of course, for a multichannel speaker configuration you'll need more
speakers and cables than for a stereo setup. Regarding quality, the same
counts as for the amplifier: even with mainstream speakers and cables you'll
be able to appreciate the sound quality improvement of SA-CD over CD, because
the wires will typically not be the bottleneck. Once you have upgraded
other parts of your chain (the player, the music carriers) you may however
become more critical of your speakers and cables, and there is no limit
as to how far you can go.
Do I need identical speakers?
Many home theater systems are primarily designed for use with Dolby
Digital and DTS where having relatively small surround speakers and larger
is perfectly normal, often supported by a setting on the receiver to switch
between identical speakers and larger plus smaller speakers. Multichannel
SA-CD is best enjoyed with five identical speakers (plus an optional subwoofer;
see the next question) or at least with rears from the same speaker family
but that doesn't mean you won't be able to enjoy great sound until you've
upgraded all of your speakers.
Do I need a subwoofer?
This depends on your taste as well as your receiver. Note that even
multichannel titles often do not use the .1 channel. If you're not using
a subwoofer it's helpful if your receiver has a feature called 'bass redirection',
to make sure you don't miss too much. Some SA-CDs include a duplicate of
the bass signal on the .1 channel for use with sub-sat systems which will
need to attenuated or disabled on full range systems.
Do I need to configure the speakers in a precise layout?
Sony and Philips recommend the following configuration for multichannel
SA-CD:
Where the subwoofer is placed is not critical: with low sounds, due to their
long wavelength, it's practically impossible to tell where they come from.
If you plan to use your setup also for watching movies you'll be glad
to hear this layout is quite compatible with Dolby Digital and DTS 5.1.
It's
not a disaster if the angles don't match exactly, for instance if the
rear speakers are further to the back. More critical probably is the distance
of all speakers. A perfect circle ensures identical travel times for the sound
from all speakers. For Dolby Digital and DTS, AV receivers often offer
time delay settings to compensate for varying distances but because DSD sound
(and analog sound) are much more difficult to process in such ways, for SA-CD
you'll probably not be able to use this feature.
With all of the sound questions above there is one advice that
always holds true: Rely on your own ears. Listen and judge for yourself.
Do I need special ears to enjoy the sound quality difference between CD and
SA-CD?
No, you don't need golden ears. Even untrained people can fairly easily
notice and appreciate the difference between 44.1-kHz 16-bit PCM and 2.882
MHz 1-bit DSD - also in stereo. Even people who are deaf on one ear have said
they notice how SA-CD sounds more natural than CD.
Do I need additional ears to enjoy multi-channel sound?
No, even with just two ears, humans have a remarkable capability to
tell the direction sounds come from - a trait we probably developed in
ancient times when this contributed significantly to our chance of survival.
References
Where can I read more?
About SA-CD in general:
About professional issues regarding SA-CD (authoring, mastering, manufacturing,
etc.):
About DSD:
About DXD:
About DVD-Audio:
About DVD-Video and the DVD format in general:
About car SA-CD players:
Glossary / list of acronyms
AAC: Advanced Audio Codec - an audio encoding scheme, used for instance
by iTunes/iPod
CD: Compact Disc
DSD: Direct Stream Digital - the audio encoding scheme used
on SA-CD
DST: Direct Stream Transfer - lossless compressed DSD
DTS: Digital Theater
Systems - a company and their standard for multichannel audio, primarily
for movies
DVD: just 'DVD'; refer to DVD FAQ
DXD: Digital eXtreme Definition: a PCM-like
high-resolution audio encoding scheme for professional editing
FAQ: Frequently
Asked Questions - what you're looking at
HDMI: High-Definition Multimedia
Interface - a digital A/V interface
i.LINK: IEEE1394 aka FireWire
IEC: International Electrotechnical Commission
- a standards body whose standards include those for SPDIF
MLP: Meridian
Lossless Packing - an audio encoding scheme used on DVD-Audio
MP3: MPEG1
Audio layer 3 - a popular but lossy audio compression standard
MPEG2:
a multichannel audio encoding scheme standardized by the Motion Pictures
Expert Group along with video encoding schemes
PCM: Pulse Code Modulation
- the audio encoding scheme used on RBCD and on DVD-Audio
PSP: Pit Signal
Processing - a digital watermark feature used on SA-CD
RBCD: Red Book
CD - the original Compact Disc Digital Audio standard that defines regular
audio CDs
SA-CD: Super Audio CD
SBM: Super Bit Mapping - a method for downconverting
(to) a PCM signal
SCMS: Serial Copy Management System - a 2-bit system
that indicates whether a CD may be copied freely, once, or not at
all
SPDIF: Sony/Philips Digital Interface - the interface commonly
known as optical and coaxial digital audio input/output
Copyright © 2007 Yoeri Geutskens
Illustrations: Copyright © Sony/Philips, used with kind
permission
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