Mastering is the last creative step in your album project before you
burn the final CD used for duplication. After recording mixes of your songs on your computer's hard drive, you'll put together a CD album or demo of those mixes. Here are some ways to do that.
What's involved in mastering? You edit out noises or false starts before the beginning of each song, put the songs in the desired order, insert a few seconds of silence between them, and make the songs equally loud. The goal is a consistent sound from track to track, so that everything flows better and the album sounds unified. You also can make the CD competitively loud or “hot” (but without destroying its sound quality).
You might prefer to send your CD of mixes to a good mastering engineer instead of doing it yourself. This person can listen to your program with fresh ears and suggest processing for your album that will make it sound more commercial. He or she is likely to have better monitor speakers and better equipment than yours. They have heard hundreds of recording projects done by others, and know how to make your CD sonically competitive.
Related Info: "You wouldn’t want to blow out someone’s multimedia speakers because one track is louder than the next."
If you plan to have your program mastered outside, burn a data CD of your mixes, which ideally are 24-bit/44.1 kHz wave files. Do not apply any signal processing to your finished mixes such as editing, level changes, compression, normalization, fades, or EQ. Let the mastering house do it with their better gear and software. Also, leave some headroom by recording the mixes at about -3 dBFS maximum.
Selecting The Song Order
Suppose you want do the mastering yourself. First, discuss the order of the songs on the album. For variety try to change keys from song to song. Here’s a suggested song order:
1. An up-tempo, exciting song that hooks the listener.
2. After a short space, an up-tempo or mid-tempo song.
3. After three or four songs, slow down the tempo.
4. Reach an emotional climax near the end of the album.
5. The last song should sound relaxed and intimate, maybe using fewer musicians.
You can drag the wave files of your song mixes into iTunes and experiment with various sequences. Once you have decided on the order of songs, you’re ready to master the demo or album as described below.
Mastering The Album
Mastering can be done with your multitrack recording software, or with an audio production program such as Steinberg Nuendo, Sony Sound Forge, BIAS Peak Pro, Sonalksis Mastering Suite, 1K Multimedia T-Racks 24, or Magix Samplitude.
1. Open or create a multitrack session set to 24-bits/44.1 kHz. Import the first song’s wave file to track 1. The waveform of the song appears as a clip or segment of audio.
It’s convenient to put each song clip on a different track, one after another (Figure 1). That way you can easily adjust the spacing between songs, and apply different fader settings and processing to each song as needed. Assign all the tracks to the same stereo bus so you can apply bus processing to them later.
2. Slip-edit or trim the beginning and end of each song clip to remove extra silence and noises.
3. Now that all the songs are in place and trimmed, add a fade-out at the end of songs that need it.
4. Next you can adjust the silent pause between songs. Two to three seconds of silence between songs is typical, but go by ear. Use a longer space if you want to change moods between songs. Use a shorter space to make similar songs flow together. A short space also works well after a long fade-out because the fade-out itself acts like a long pause between songs.
5. Click on and play each song’s waveform to check for loudness. Make all the songs equally loud by adjusting the track’s fader for each song. If most songs are equal in level, set the fader to zero before each of those songs in order to avoid processing. Then turn down any louder songs and turn up quieter songs to match the rest of the songs. Do this by ear. CAUTION: If you increase a song’s level, make sure the peaks in the song don’t clip.
6. Apply EQ to songs that need it. For example if one song has more bass than the others, turn down its low-frequency EQ until it sounds like the other songs. A useful tool for this purpose is Harmonic Balancer at www.har-bal.com.
7. After all your songs are volume-matched and EQ'd, you might want to apply peak limiting and normalization to the mix bus in order to get a “hot” or loud CD. The idea is to knock down the peaks in the waveform because they do not contribute to perceived loudness—the average level does. Once you limit the peaks about 6dB, you can normalize (raise the overall level) and thus create a louder program. Normalizing to 100% of full scale can create errors with some CD players, so you might normalize to 96% or -0.3 dBFS.
Burning a CD
At this point, all your songs sound equally loud, and they might be peak-limited and normalized. You are almost ready to burn a CD.
You can use the CD-burning software that came with your computer CD burner, or use other software. Some examples of CD-burning programs are Roxio’s Easy Media Creator and Record Now Media Lab, Nero, Cakewalk Pyro Audio Creator, Golden Hawk Technology's CDRWIN and Stomp’s Click ‘N Burn. Some DAW software includes a CD-burning application.
Now you have two options: burn a CD from one long wave file, or burn a CD from several short wave files (one per song). Here's what to do:
Option 1: Write down the start time of each song in minutes, seconds and frames. Turn on dither and export the mix to one long 16-bit wave file that contains all the songs. Use CDRWIN software to write a cue sheet that lists the start time of each song. Burn a CD using CDRWIN. Each track on the CD will start at the beginning of each song. You're done!
Option 2: Slide each song back to time zero. Solo track 1 and highlight its clip. Export the mix (only the mastered song 1) to a new 24-bit wave file without dither. Repeat for each track and its song. Import the mastered song 1 wave file into a new 24-bit project. Slip-edit the beginning and end if necessary, and export the song as a 16-bit wave file with dither turned on. Repeat for each song.
If you used option 2 above, you now have several mastered wave files. Here's how to burn a CD of those files.
1. Start the CD-R burning software.
2. Select the wave files you want to put on the CD-R, drag them to the playlist, and arrange them in the desired order. Each wave file must be 16-bit/44.1 kHz. The total playing time must be 74 minutes or less.
3. Choose "Disc image" instead of "On the Fly" to prevent disc errors. Set the CD-burning software to Disc-at-Once mode. Enable Buffer Underrun Prevention.
4. Set the burn speed. The recommended speed to prevent errors is 2X to 4X when making a master CD to be sent out for replication. But some CD recorders and blank CD-Rs have fewer errors at higher speeds.
5. Most CD burning programs put 2 seconds of silence between recorded tracks. Some let you adjust the length of the silent gap.
6. Start recording the CD-R. Do not multitask while the CD is recording.
The CD is finished. To prevent error-causing fingerprints, handle the disc only by the edges. Pop the disc in an audio CD player, press Play, and check that all the tracks play correctly.
There's your mastered CD, ready to copy or to send to a duplicator. Be sure to include a CD log with song titles, start times, song durations and total running time. Congratulations on your new album!
Bruce Bartlett is the author of "Practical Recording Techniques 5th Ed." and "Recording Music On Location." He offers a mastering service at www.bartlettrecording.com/mastering.html , and runs a microphone company at www.bartlettmics.com .