In many cases, surround sound production carries with it the assumption of high-resolution audio — audio that is sampled at greater than 16-bit word length and higher than 44.1 or 48 kHz sample rates. And rightfully so: Most surround audio is done at 24-bit resolution, although 44.1 and 48 kHz remain common sample rates. However, with DVD-audio, higher sample rates are becoming more commonplace, especially 96 kHz. And DVD-audio also allows for even higher sample rates with stereo tracks — stereo 24-bit, 192 kHz releases are on the shelves now.
If your studio is reasonably current, you may already have hardware that supports higher resolution audio. Many computer audio interfaces, digital recorders, and digital mixers have been supporting at least 24-bit operation for quite some time; higher sample rates are also becoming more and more common, especially in computer audio interfaces and digital mixers.
SACD (Super Audio Compact Disc) poses a slightly more difficult situation. It uses a different digital audio format, DSD (Direct Stream Digital) than CDs and DVDs, which use the more-familiar PCM (Pulse Code Modulation) format. The tools required to produce SACD aren’t as readily available to most of us — few of us have DSD-compatible analog-to-digital and digital-to-analog converters, let alone applications that will let us mix or edit DSD-format audio. However, DSD tools are starting to get out there, and their price will drop in the months to come.
Even if higher resolutions aren’t being requested by your clients or you are still working mainly with CD releases, there’s good reason to consider working at higher sample rates and bit depths on your projects. Thanks to various technologies such as dither, noise-shaping, and downsampling, many of the sonic benefits of working at higher resolutions are still preserved even if the final release is at 16-bit, 44.1 kHz.
There’s also the issue of archiving for future release on other media. If the CD you’re working on today ends up getting picked up for release on DVD-audio at some point in the future, it would be worth it to have your source tracks and original mixes at a higher resolution.
If you’re buying new digital recording gear and/or software, chances are it will come out of the box ready to support at least 24-bit operation, and it’s likely that it will support higher sample rates. If so, you’re golden.
If you’re thinking about upgrading your existing equipment, take a serious look at what high resolution will mean to your studio now, as well as in the future. It’s a good bet that as new media for audio delivery emerge, they’ll be of higher-than-CD resolution (except for compressed delivery formats, but even here, the final product can often benefit from starting with high-resolution source tracks).