DSD Mastering & Super Audio CD
Super Audio CD (SACD) offers high quality, multi-channel surround audio, CD compatibility, copy protection, with added graphics and features. SACD specifications are:
Philips and Sony have cooperated in developing SACD which uses a different audio coding method during the recording process, Direct Stream Digital (DSD). An SACD is essentially a DVD, but the information contained on the format is encoded using Direct Stream Digital technology, rather than Pulse Code Modulation (PCM). PCM is the encoding used for standard CD and DVD-Audio and DVD-Video.
DSD was chosen as the encoding format for SACD because of its more transparent and musical quality over standard PCM, even at high sampling rates. Use of DSD encoding avoids the multiple stages of filtering and decimation that is inherent in PCM encoding. Even the standard CD layer of the SACD benefits from the DSD technology. Down-converted through the Sony Super Bit Mapping Direct process, the CD layer exhibits much of the smooth, analog-like qualities of the DSD recording. Multichannel surround is accomplished with lossless compression of the 6-channel DSD mix to fit the immense amount of data on the disc.
Watermarking for copy protection uses pit signal processing (PSP) which cannot be copied by any known piracy process. There is also a visible watermark.The hybrid CD/SACD disc format allows SACD to play on existing CD players as well as Super Audio CD players.
This is possible by molding the CD-Audio pits on the outside of the otherwise blank DVD substrate (see below) and using a semi-reflective layer for the DVD , thus allowing the CD-Audio layer to be read by a conventional CD player.
The result would guarantee that SACDs would be playable on existing CD players, easing consumer fears of obsolescence. However 'hybrid' discs are more difficult and therefore more expensive to manufacture than CDs. For this reason, the backward-compatible hybrid disc is an option and is not used by all companies releasing SACDs.
The SACD specification is contained in the Scarlet Book. SACD discs are DVD discs in that they use the same sector size, error correction and modulation as DVD discs and the same file system (UDF plus ISO 9660).
Q:I have an extensive Compact Disc collection. Does SACD make my collection obsolete?
A:CD is the most successful digital music format in history with over 13 billion Compact Discs worldwide. CDs will be the leading music format for years to come.
Q:Will Compact Discs play on an SACD player?
A:Absolutely. Every SACD player is fully compatible with every audio Compact Disc ever produced.
Q:Will SACDs play back on my portable CD player or car CD player?
A:Hybrid SACDs will. They include both a high-density SACD layer and a standard-density CD layer, for playback compatibility with the over 700 million CD players worldwide. And remember, audio CDs will play back on SACD players.
Q:What's more important in SACD, the specs or the sound?
A:Specifications are important, since SACD achieves unprecedented frequency response and dynamic range. But SACD's sonic advantages are even more significant. DSD encoding eliminates aliasing filters and decimation digital filters in the recording studio, as well as interpolation digital filters in playback. This eliminates entire classes of phase errors, requantization noise, passband ripple and ringing. The process is far simpler than conventional PCM technology.
Q:When will universal players be available that can play SACD, DVD, and CD?
A:Many hi-fi manufacturers have plans for 'universal' players to be released in 2001. Sony Electronics plans on having SACD playback capability in all their CD players by 2001.
Q:When multi-channel SACDs are available, will they play on the Sony SCD-1 and SCD-777ES?
A:Absolutely. Multi-channel SACDs will also include a separate 2-channel version of the same music. Two-channel listeners will hear the stereo mix-down exactly as the artists and producers intended, with no "down-mixing" required.
Q:When will surround SACDs and players be available?
A: TBA
Q:What about DVD-Audio?
A:DVD-Audio is an extension of the DVD-Video and DVD-ROM multimedia platform. DVD-Audio is primarily positioned as a multi-channel format to coincide with the rapidly expanding multi-channel market, with video. In contrast, as an extension of Compact Disc, SACD is a "pure audio" format, the natural choice for those who demand highest quality sound.
Q:Is there room in the market for two high-resolution formats? Isn't this like Beta vs.VHS?
A:Today's digital world offers many music options. Some consumers will receive their music by satellite or cable -- or download music from the Internet, while the vast majority of consumers will continue to enjoy their current CDs for many years to come. Some consumers will listen to music on convergence formats like DVD-Audio with video. Critical listeners who demand nothing less than the highest sound quality will demand Super Audio Compact Disc. Unlike the days of "Beta vs VHS", we will have players that can play all the formats.