Mastering with Sound Forge (Part 1)
by Craig Anderton
Back when vinyl ruled the earth, mastering (the prepping of a final, stereo mix for commercial release) was an arcane and complex process, because it had to accommodate vinyl's significant physical limitations. Since the advent of digital audio, the process of mastering has become much easier; programs like Sound Forge software, combined with signal processing plug-ins, have made it possible (although not necessarily desirable!) for just about anyone to master their own recordings. But what exactly does mastering involve?
What mastering does
Mastering accomplishes four principal tasks:
1. Format conversion. For CD release, an audio file must be converted to 16 bit resolution and a 44.1kHz sampling rate. Many mixes come to the mastering engineer at a higher resolution, such as 24 bits at 96kHz, or even on analog tape.
2. Assembly. This process takes a collection of individual tracks and turns them into a single, cohesive "album" or listening experience. This means no awkward volume or tonal changes between tracks, as well as a "flow" that provides the optimal artistic impact.
3. EQ. This has two main functions in mastering. One is to ensure consistent tonal qualities from track to track, while the other is to fix specific tonal problems within individual tracks (like reducing resonances—buildups in certain frequency ranges).
4. Dynamics. Vinyl had a limited dynamic range, so the wide dynamic range of music had to be reduced in order to fit. This meant bringing down the peaks so that the needle wouldn't jump out of the grooves, while bringing up softer passages to raise them above the surface noise. Even though CDs don't have these limitations, dynamic control is still used (unfortunately, often to excess) because it can create a CD that sounds "louder" and "jumps out" at the listener. Although a CD that's cut really loud has a dramatic initial impact, it eventually becomes fatiguing. A well-mastered piece of audio should retain as much dynamics as possible, as dynamics are a huge part of the emotional impact of music. Paradoxically, a lot of older vinyl records have more dynamics that today's CDs; many feel those old records provided a more satisfying listening experience.
Can you master your own recordings?
Yes…but should you? A professional mastering engineer brings years of experience, and can help make your recordings sound more "commercial." (Interestingly, Sony offers an online mastering service where people can send their files to professional mastering engineers, who will then master those files for a reasonable fee. This type of mastering business model will likely become more common in the years ahead.)
However, while mastering engineers would like you to believe only they can do the job right, if you have good ears, patience, and the right tools, you can certainly learn to master less critical recordings (e.g., recordings of a live gig, or tweaking the audio track of a video you did on a camcorder). All mastering engineers had to start somewhere, and while your first efforts may not be the zenith of the mastering art, over time you'll improve.
Next issue, we'll cover more Sound Forge mastering techniques.
Craig Anderton is editor in chief of Harmony-Central.com, and executive editor of EQ magazine. He has lectured on technology and the arts in 10 countries, 37 states, and in three different languages.