What is Super Audio CD? .: article August 2004
This compact disc looks like a normal CD and plays on all standard players and computers. But thanks to an additional CD-layer the hybrid SACD is much, much more. For an unforgettable audio experience, you've really got to hear it on a Super Audio CD player in 5.1 surround. Embrace yourself in the 360 surround field with the ambience as the music is performed. If you care passionately about music, then SACD will inflame that passion as never before.
The Super Audio layer uses a new and radically different technology called Direct Stream Digital (DSD) to convert music into a digital signal that can be stored on a disc. Compared to the traditional PCM method (the technology used for CD), DSD offers a much higher resolution by following more closely the original wave form of music. With a frequency response of over 100kHz and a dynamic range over 120dB across the audible frequency range – some 64 times higher resolution then CD – Super Audio CD offers music reproduction that reveals details you just can’t hear on a normal CD. The Direct Stream Digital™ pulse train "looks"" remarkably like the analogue waveform it represents. More pulses point up as the wave goes positive and down as the wave goes negative.
DSD uses 1-bit delta-sigma modulation and a sampling frequency 64x higher than CD. Super Audio CD recordings don't have to subject the original sound waves to the decimation and interpolation stages associated with PCM. Hence DSD sound reproduction is much more natural and accurate in staging, and is often favourably compared with the best analogue recordings, but without the hiss and other artefacts that are also associated with analogue recordings. Even the SACD's 16-bit CD layer can sound better, if it's based on a Direct Stream Digital studio master. The Super Bit Mapping Direction process can be used to down convert to the 16-bit format, which enables you to hear more of the original master.
The introduction of DVD video has spawned huge interest in the surround sound experience. With Super Audio CD, music too can be mixed to 5.1 multi-channel surround sound (instead of just stereo left and right). The DSD signal can be delivered in up to 6 separate channels (front left, centre, front right, left rear, right rear + subwoofer) making it possible to maintain extremely high resolution across all speakers without even the slightest sacrifice in sound quality.
Super Audio CD data is stored on the same physical carrier as DVD-Video. Making use of this highly successful consumer product brings many advantages, such as the use of mass produced components and making combination players which play both SACD and DVD-V. This silver disc can store more than seven times the information of the standard CD, providing up to 74 minutes of full resolution surround music – the same duration as a stereo CD. A Super Audio CD has two distinct mixes, one for stereo and one for multi-channel.
Furthermore, there is an option to add a separate CD layer to the DVD disc: the so called Hybrid Super Audio CD. Hybrid SACD’s can be played back on virtually all CD drives and players as well as all standard DVD-Video systems. This makes Super Audio CD’s compatible with all 11 billion CD and DVD players used around the world.
Super Audio CD offers the world’s most secure digital carrier, utilising a combination of physical and electronic protection barriers. These are layered around the audio content in five independent layers, including a combination of mechanical and encryption-based protection systems that cannot be broken using any current hacking technique. The end result is that when you buy a Super Audio CD in a music store, you can be confident that it’s the genuine article and not an illegal, inferior quality copy. The CD layer on the hybrid disc is similar to a conventional CD in that it’s open to copying onto other carriers for home use.
A hybrid Super Audio CD will play in all CD and DVD players, at CD quality. So if you want to be ready for the future but don’t have a SACD player yet, just start buying your albums as hybrid SA-CDs. Go ahead and buy the new Ensemble 96 “Immortal Nystedt” album on SACD: enjoy the CD now and the SACD later.
compiled from www.superaudio-cd.com 20©05 Morten Lindberg