Last update: October 12, 2011
This FAQ aims to be the most comprehensive FAQ on the web concerning SA-CD, but also independent, unbiased, practical and readable.
If you have any corrections, suggestions, or relevant questions that you don’t see answered here, please use our feedback form.
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.
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.
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.
That’s to distinguish SA-CD from SACD, la Société des Auteurs et Compositeurs Dramatiques – a French copyrights body.
Scarlet Book is the name of the official specification of the SA-CD format.
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).
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.
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.
Yes. Single-layer SA-CDs look ‘plain silver’ while hybrid ones have a goldish shine to them.
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.
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.
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.
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.
Not necessarily but in practice it generally is. In some cases you may notice slight variations in playing time.
Pit Signal Processing has nothing to do with PlayStation Portable, another PSP acronym coined by Sony.
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.
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.
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.
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 conversion from all PCM sample rates.
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.
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.
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.
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.
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 DTS 5.1_Music_Disc.
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 .
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.
A DSD Disc is a recordable or rewritable DVD with DSD on it that you can create yourself. For a far more detailed explanation see our DSD Disc guide.What is a DSD-CD?
A DSD-CD is simply a normal ‘Red Book’ CD that was derived from a DSD master (which in turn may have been generated from an analog master tape). As explained above, DSD can be downsampled very elegantly to PCM at various resolutions, including the 44.1 kHz 16-bit signal used on RBCD. Although DSD-CDs carry a DSD logo, they do not contain a DSD signal and are definitely not SA-CDs. DSD-CDs are primarily offered in Hong Kong, with repertoire from Cantopop artists like Sally Yeh.
It might. Blu-ray Disc (BD) can carry high-resolution discrete multichannel lossless audio. As far as we're aware, DSD has not been specified as one of the optional audio formats in the Blu-ray Disc standard (nor has DXD) but formats such as Dolby TrueHD and DTS-HD Master Audio, even though PCM-based, provide sound quality comparable to SACD, with up to 7.1 channels. It's also possible to create audio-only Blu-ray Discs; these contain a menu but no further video and can be operated without the need to use a display, simply using the number keys and colour keys on the remote control. See Pure Audio Blu-ray.
So far however there's little sign of this succession happening. Not only the catalog of 'BD-Audio' titles is negligible compared to that of SA-CD but also the number of titles released annually is hardly significant. Even if you only consider pop/rock titles, BD-Audio is just beginning to have some impact. BD-Audio titles are covered on our news page and in this modest store.
If you consider purchasing a Blu-ray Disc player you may want to buy one that plays SA-CD.
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.
No, some SA-CDs are packaged in traditional jewel cases, digipacks or other forms.
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.
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.
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.
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.
No HD-DVD player with SA-CD support was ever made. SA-CD-compatible Blu-ray Disc players include besides (the first two generations of) Sony’s PlayStation 3: Oppo BDP-83, Cambride Audio azur 650BD, Lexicon BD-30, Denon DBP-4010UD, Denon DVD-A1UD, Marantz UD8004, Marantz UD9004 and McIntosh MVP881BR. Check our overview.
Hybrid SA-CDs can be played as CDs on all consoles that support ‘Red Book’ audio CD. In principle that means all consoles with a CD drive but the Xbox360 is known to have issues finding the CD layer of hybrid SA-CDs. 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).
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.
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.
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 Sony DADC, Crest Digital, Sonopress and Media Hyperium
What you can do is make a DSD Disc, basically a DVD with DSD audio on it. Check our comprehensive ‘how to’ guide.
There are various types of ‘digital outputs’:
There are two digital connections that can provide DSD input:
The number of SA-CDs released worldwide currently well exceeds 6,000. Some early titles are out of print but about 4,000 of them can be ordered. Arguably, a few titles in the list are counted twice because of different releases that were first released as a single-layer disc and later as a hybrid disc, or first as stereo-only and later as multi-channel. ‘Brothers in Arms’ by Dire Straits was released in a jewel case and – under a different article number – in a so-called digipack.
Check the database on www.sa-cd.net – it’s the most comprehensive list of SA-CDs on the web.
At the time of the most recent update 468 labels have released one or more SA-CDs.
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.
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 manufacturers”. 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.
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.
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.
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.
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.
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.
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.
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.
About SA-CD in general:
About professional issues regarding SA-CD (authoring, mastering, manufacturing, etc.):
About available DVD-Audio titles:
About DVD-Video and the DVD format in general:
About ‘universal’ SA-CD/DVD-Audio players:
About car SA-CD players:
SA-CD FAQ: © 2007-2011 Yoeri Geutskens
Illustrations: copyright Sony/Philips, used with kind permission.