The DSD/SuperAudio CD format seems to slowly be coming back into focus, with recent releases from Korg and Sony, after many thought it was dead. Steinberg released software support for DSD some time ago in Cubase, but is it possible today to use DSD with Cubase or other desktop recording systems? If not, what are the alternatives to setting up a DSD workflow for recording, mixing and mastering to Super Audio CD?
SOS Technical Editor Hugh Robjohns replies: DSD and Super Audio CD are related but different things, and it might be worth clarifying that first. DSD — Direct Stream Digital — is a generic PCM digital audio data format, but one that uses only one bit at a very high sample rate. The standard rate is 64 times 44.1kHz, which is 2.8224MHz. However, the standard DSD rate has long been argued as insufficient, and a higher DSD rate of 5.6448MHz is now offered by some recorders, including the Korg range.
The Super Audio CD (SACD) uses this data format for its 'high resolution' stereo and (if provided) surround tracks, while often also including standard Red Book CD stereo audio on a separate physical layer in the disc (the so called Hybrid Disc, which accounts for most commercial releases). Copyright-protection data is embodied in a physical modulation of the width of the data‑stream 'pits', and only licensed SACD production plants have the technology to do that. A disc without that physical copyright‑protection data is not playable on current standard SACD players.
Processing native DSD streams in a DAW environment is possible in a fashion, but isn't easy and has to contend with some significant technical issues. As I understand it, there are currently only two DAWs that can process (ie. mix, equalise, control dynamics of, and so on) DSD data directly, and they are Merging Technologies' Pyramix and Sony's Sonoma. SADiE used to offer its System 5 DSD platforms, and Sonic Solutions also had a DSD platform, but both are now out of production.
Most systems that claim DSD compatibility actually transcode the DSD audio to high‑resolution PCM (24/96 or 24/192, for example), do all the signal processing at that resolution, and then transcode the result back to DSD. To be honest, this is a very practical way to work, and the easiest way to maintain the kind of workflow and processing facilities that we are all used to in music production.
Some DAWs already have suitable DSD transcoding facilities, and Korg offer their own 'AudioGate' software that can transcode stereo DSD files to various multi‑bit PCM formats (www.korg.com/downloads/pdf/AudioGate_Users_Guide.pdf). There is also some crude editing capability, allowing DSD files to be divided or combined — so basic 'top and tailing' or straight cut‑editing is possible — and gain can be adjusted over a +/‑ 24dB range, and automated fade‑ins and fade‑outs implemented.
DSD files can be burned to DVD media as standard UDF (Universal Disk Format) files, and Sony have released a specification for doing this (see www.ps3sacd.com/downloads/DSDDiscFormatSpecs.pdf). However, since the physical copyright protection data of a standard SACD can't be imposed in any computer DVD drive, these DSD discs can't be played back on standard SACD players. However, apparently Sony PS3 machines recognise the format and will play it back, as will all Sony Vaio computers and any standard PC with Windows Media Player 10/11 upgraded with the DSD plug‑in.