What is DXD?

Digital eXtreme Definition (DXD) is an digital audio format that originally was developed for editing high-resolution recordings recorded in DSD, the audio standard used on Super Audio CD (SACD). As the 1-bit DSD format used on SACD is not suitable for editing, alternative formats such as DXD or DSD-Wide must be used during the mastering stage. In contrast with DSD-Wide or DSD Pure which offers level, EQ, and crossfade edits at the DSD sample rate (64fs, 2.822 MHz),^[1][2] DXD is a PCM signal with 24-bit resolution (8 bits more than the 16 bits used for Red Book CD) sampled at 352.8 kHz – eight times 44.1 kHz, the sampling frequency of Red Book CD. The data rate is 8.4672 Mbit/s per channel – three times that of DSD64. DXD also utilizes the vast array of plugins also available to PCM based digital audio workstations, such as Cubase, Logic, Digital Performer, etc.

https://en.wikipedia.org/wiki/Digital_eXtreme_Definition