SACD
When improvements to the humble Compact Disc were being engineered in the mid-90s, it seemed like the DVD Audio format was to be the heir. The Beta videotape format must have worked out so well for Sony, they decided to strike out in their own direction again with a strictly licensed proprietary format. The Super Audio CD (SACD) was born.
SACD uses the Direct Stream Digital (DSD) signal processing technique. This process takes 1-bit (sigma-delta modulation) samples at a frequency of 2.8224 MHz. In comparison to DVD Audio's high-resolution PCM technique, SACD is completely revolutionary, taking rather small samples at an incredibly high rate. Like DVD-Audio, SACD is also a 5.1 surround format designed for music. Fans of SACD claim in comparison to DVD-Audio it sounds warmer, more like an analogue recording, where DVD-Audio can seem sterile in its presentation.
