DSD128
A 1-bit DSD format with a sampling frequency of 5.6448 MHz, featuring a data rate 128 times that of 44.1 kHz, is primarily used for file distribution, recording, and production, rather than for SACD discs.
Explanation
DSD128 is a 1-bit Direct Stream Digital specification with a sampling frequency of 5.6448 MHz, which is 128 times the frequency of 44.1 kHz and twice that of DSD64. It is sometimes referred to as Double-Rate DSD or DSD 5.6 MHz.
The raw data rate is 5.6448 Mbit/s for mono and 11.2896 Mbit/s for stereo. Higher oversampling rates extend the operating range of noise shaping to higher frequencies and provide different conditions for filter design, while simultaneously increasing the storage, transmission, and processing load. The actual noise distribution still depends on the modulator and production process; audible quality cannot be inferred solely based on the multiplier.
DSD128 is primarily distributed and exchanged in DSF, DSDIFF, or other DSD-compatible file formats. The SACD specification uses DSD64 at 2.8224 MHz; there are no standard-compliant DSD128 high-density audio tracks. Burning DSD128 files to a data disc does not result in an SACD.
Device support must distinguish between file decoding, USB or network transmission, DoP packaging, and internal processing. DoP transmission of DSD128 typically requires a higher PCM frame rate than DSD64, and both the interface and drivers must support this. Many players convert DSD128 to PCM when applying digital volume control, equalization, or room correction; the output label reflects only a specific stage in the chain.
High-speed DSD files may also be converted from DSD64, PCM, or analog sources. The final bit rate does not prove that the recording was originally in DSD128, nor can it alone be used to judge the quality of the master.