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NuPrime
3
From Hi-Res to Extreme Resolution
High-volume storage has become cheap enough for the proliferation of hi-res music
beyond CD quality (16-bit/44.1kHz). Storing 24-bit/96 kHz or 192 kHz music with PCM
encoding in uncompressed format (typically WAV) or lossless compression format (such as
FLAC, M4A, WMA) has become standard practice for audio enthusiasts.
Music is typically recorded in 24 or 32-bit PCM or DSD format at the recording studio. It is
then converted to lower resolution format for mass-market distribution.
Pulse-code modulation (PCM) is a method used to digitally represent sampled analog
signals. It is the standard form of digital audio in computers, compact discs, digital
telephony and other digital audio applications. In a PCM stream, the amplitude of the
analog signal is sampled regularly at uniform intervals and each sample is quantized to
the nearest value within a range of digital steps. A PCM stream has two basic properties
that determine the stream's fidelity to the original analog signal: the sampling rate, which
is the number of times per second that samples are taken, and the bit depth, which
determines the number of possible digital values that can be used to represent each
sample. DXD is simply PCM 24-bit/352.8 kHz.
Direct-Stream Digital (DSD) is the trademark name used by Sony and Philips for their
system of digitally recreating audible signals for the Super Audio CD (SACD). DSD
uses pulse-density modulation encoding – a technology to store audio signals on digital
storage media that are used for the SACD. The signal is stored as delta-sigma modulated
digital audio, a sequence of single-bit values at a sampling rate of 2.8224 MHz (64 times
the CD Audio sampling rate of 44.1 kHz, but only at 1⁄32768 of its 16-bit resolution).