Tech Tip:10 Essential Mastering Tips
If you're going to try your hand at mastering, this is required reading.
By Craig Anderton
- Make very small changes when EQing, because an increase or decrease in one frequency range has repercussions elsewhere. For example, if you boost the treble, the bass becomes less prominent. It's amazing how even a 0.5dB change can make a noticeable difference. Adjust EQ to what sounds right, then halve the amount of boost or cut you added. This gives your ear a chance to get acclimated to the change in sound. You can decide later whether you want something more drastic.
- Always save and back up your original unmastered, 2-track or surround mix before you start mastering, and work on a copy.
- Duplicators will often reject CDs if the level hits 0 for several samples in a row. Yet these very short overloads may not be objectionable to the listener. To get around this problem, after assembling the entire CD, normalize it to -0.1 dB. This leaves just enough headroom that the CD won't be rejected for "overs."
Normalizing an entire CD to something less than 0 can reduce the chance of rejection
from a CD duplicator. However, you probably don't want to normalize each track individually, as that could interfere with the song-to-song level cosistency.
- Don't add song fade-ins or -outs when mixing. Tunes may need a longer or shorter fade than anticipated. If you build a fade into the mix, you can only make it shorter.
- Don't do any more processing than needed. These operations sometimes round off numbers; if these errors accumulate, there can be an audible "fuzziness." While this was mostly a problem with 16-bit systems -- 32-bit floating resolution has given a lot more operational headroom -- it's still a good idea to keep any processing to a minimum.
- When mastering with a digital audio editor, save the setup you use (plug-ins, levels, etc.) as a preset. For example, Wavelab has a Master Section Presets option. If the vibe of the CD changes over the course of mastering, you can go back to earlier tunes, recall the preset, and make a few tweaks rather than start over from scratch.
Saving often-used combinations of effects can make it easier to get up to speed if you need to make any revisions.
- If possible, test the album's song order before you start mastering. Use your CD burning program or Apple iTunes-type program to assemble a "playlist" of tunes, and record it to Red Book CD, portable MP3 player, Minidisc, etc. Live with the order for a few days so you're sure everything flows smoothly.
- Use normalization sparingly. Normalization sounds like a great idea: click a button to amplify your signal so that the peaks just reach the maximum available dynamic range. But music doesn't work like that. A heavily compressed tune may seem much louder than a less compressed tune whose peaks are actually higher.
- Think high resolution audio at all times. Save your final mastered versions in at least 24-bit resolution, even if the target playback medium is a standard 16-bit CD. Then apply dithering to the high resolution file to create the best-sounding 16-bit file.
- If you mix to DAT or transfer tunes to DAT prior to sending them to a duplicating house, record a minute or two of "digital black" (silence) at the tape's beginning. This gets past the part of the tape that is most likely to have questionable surface characteristics. You can then transfer the DAT digitally to your computer for editing. Also, eject any digital tape in a space between songs. Should any tape damage occur while threading or unthreading, your song will be spared.