Mastering in Your Home Studio

By David Franz

What is Mastering?
Mastering is the last stage in the production process — it takes place after you've finished mixing your entire project. Mastering can take your home studio recordings to the next level, making your final mixes sound more like professional recordings.

The main purpose of mastering is to sonically treat your final mixes so that 1) the recording's frequency spectrum works well on all types of playback systems, from one-speaker clock radios to hi-fi home stereos, 2) the overall volume level is "competitive" with other mastered recordings, and 3) the overall EQ and volume of each song creates a cohesive final product from track to track.

Other considerations in mastering are 4) checking and/or adjusting the left/right balance, phasing, and stereo imaging of the tracks, 5) listening for and fixing dropouts, glitches, and other unwanted noises, 6) possibly adding real or simulated tube/analog gear into the signal path (if working with digital recordings), 7) dithering and noise shaping, and 8) bouncing and burning the final CD master with the correct track order, timing, and fades.

Step One: Bounce Down Your Final Mixes
First, make sure you have a stereo master fader track in each song's mix session. Check the output levels — the master fader shouldn't peak ("clip") when playing back. It's not a bad idea to print your final mix a couple dB lower than the 0.0 dB mark. The mix output won't be as high as you ultimately want it to be, but mastering will boost it up to a competitive level. Also, I recommend not using any plug-ins on your master fader during the final mix bounces. Whatever plug-ins you want to use over the entire mix can be added during the mastering process.

This also goes for dither. There's no need to add dither when you bounce the final mix, because you should bounce the tracks at the same bit depth and sampling rate as your Pro Tools session. That is, keep the highest resolution possible going into the mastering phase. For example, if you recorded at 24 bit/96 kHz with your 002, bounce each mix at the same bit depth and sampling rate without dither. Use dither only on the final mastered bounce.

I also recommend bouncing your tracks without volume automation on the master fader (e.g., fadeouts), because it's good to retain the flexibility to create that automation in the mastering session.

Highlight the portion of the track you want to bounce and select "Bounce to Disk" from the File menu. In the "Bounce to Disk" pop-up window, use these parameters (as seen in Fig. 1):

The "Bounce to Disk" window with mastering parameters. There's no need to "import after bounce," because you're going to make a new session for mastering and will import the track into that new session

Bounce Source: the main stereo output of your system
File Type: whatever file type you prefer (I usually use .wav files)
Format: multiple mono files (best type for loading back into Pro Tools for mastering)
Resolution: same bit depth as your mix session (to keep the highest resolution)
Sample Rate: same sample rate as your mix session (to keep the highest resolution)

Step Two: Create a Mastering Session
Once you've bounced all the tracks for your entire project, bring all the final mixes into a new Pro Tools session. Create a new session that has the same bit depth and sample rate as the final mix sessions (the highest resolution possible).

Import all of the multiple mono final mixes into the session using either the "Import Audio to Track" command from the File menu or the "Import Audio" command from the Audio Regions List pop-up menu. Place each song on its own track if each song needs individual attention (for example, special EQ), or simply place them on two stereo tracks with the songs lined up in sequence, as in Fig. 2.

Pro Tools session setup for mastering on two stereo tracks (Edit window)

Place the songs in the right order, and with the approximate spacing to simulate the entire project. This will give you a sense of the cohesiveness of the project when you play it all back. Don't forget to add a stereo master fader track to your session.

Once you've got all your final mixes into your mastering session and have organized that session, you're ready to begin the mastering process.

Step Three: The Mastering Process
The usual signal path for mastering a track is through EQ, Compression, Peak Limiting, and Dither/Noise Shaping. We'll start with EQ, and cover the other parts of the mastering signal path next month.

Use equalization (EQ) plug-ins or outboard EQ hardware for general EQing and/or honing in on specific frequencies to boost or cut. Applying a broadband EQ (like Waves Linear Phase mastering EQ) on the master fader track in your session can help all the tracks fit into a more cohesive sonic picture. However, I'm not suggesting that you use the same overall EQ setting on all songs. You'll usually want to tweak the overall EQ on each song. I recommend saving each EQ setting with the name of the song in the setting title. For instance, "Master EQ — Last Mistake."

Waves Linear Phase EQ plug-in

For specific track EQ, add a plug-in to the individual audio track instead of the master fader. Just don't overload the track with a massive boost. Boosting a frequency that peaks out your EQ plug-in can cause digital distortion — a definite no-no in the mastering process. Remember, cutting frequencies is part of good EQing technique too.

A tried and true way to determine what frequencies to boost or cut while mastering is to listen to the frequency content of mastered recordings you really like. Listen to how they sound on your speakers, then try to emulate the frequency curve. Tools like Waves' PAZ Analyzer can help you visually analyze the frequency content of a track — but rely on your ears more than your eyes. (The PAZ Analyzer plug-in is also handy for checking out the Left/Right balance, phase, and stereo image of the tracks.)

Waves PAZ Analyzer plug-in

Besides creating an overall sonic picture, EQ in the mastering process can further define the bass sound, add energy to (or cut the crispiness of) the high end, tighten up the middle frequencies, and sometimes even make the vocal track (or another lead track) stand out more.

Thanks to Scott Elson (my close friend and protégé of legendary mastering engineer Bob Ludwig at Gateway Mastering) for his contributions to this article. To learn more about Scott, mastering, and Gateway, visit Scott's web site (www.scottelson.com) and Gateway's site (www.gatewaymastering.com).

Like what you see in this column? Check out my book Producing in the Home Studio with Pro Tools (2nd Edition). You can buy it online right here through Digidesign's website, or visit www.protoolsbook.com. Interested in personal instruction on Pro Tools from yours truly? Visit www.berkleemusic.com and learn about several amazing Pro Tools learning experiences available online though Berklee College of Music. Wanna see my studio and hear some samples of my work? Visit www.undergroundsun.com.

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