There are many ways to set up a mastering session. This chapter describes one proven layout, its routing, and the reasoning behind it.
Do as little as possible
The goal in mastering is to change as little as necessary. The song will need some adjustments, but you must be in full control of everything added to the signal - and sure that nothing is changing the audio by accident on its way through the session.
Setting up becomes like a DJ plugging in their whole rig in the dark, five minutes before a set, with people talking to them: there is no preset, only practice. Your setup will evolve over time.
The five elements
If your DAW allows, use five separate channels. Some DAWs need elements combined.
- The premaster
- The master bus
- The print (export) channel
- The reference track
- The meter bus - the sum of the print channel and the reference
1. The premaster
The premaster goes on its own audio track. Its peak meter shows the source level at any time, and any restoration, trimming or gain adjustment is done here, before processing.
Output: feeds the master bus. (If your DAW cannot route one audio track into another, put the premaster and master bus together on one channel.)
2. The master bus
All mastering processing goes here - audio effects only - in your chosen order of operations (see that chapter).
Output: feeds the print channel.
3. The print channel
The print channel records the output of the master bus in real time. If your DAW cannot do that, use real-time export, or offline rendering as a last resort.
Printing means you hear any artefacts as they happen and can fix them without waiting for a render, and the audio passes through no export encoder - what you heard is exactly what you get. Print before the meters, in case a meter plug-in adds gain or a monitoring filter is left on.
Output: feeds the meter bus.
4. The reference track
The most important tool in the session - a measuring tape more than a song. Use it to calibrate your meters and to judge when the master is "done". With practice this comparison gets faster, but it should always be a challenge.
Output: sums into the meter bus. Switch between it and the premaster during playback, at matched levels.
5. The meter bus
The meter bus is where everything is measured: loudness, peaks, true peaks, crest factor, spectrum, stereo image. It double-checks your ears and gives a consistent system of measurement for both your master and the reference.
The signal flow
- Premaster (track 1) → master bus (track 2)
- Master bus (track 2) → print track (track 3)
- Print track (track 3) → meter bus (track 5)
- Reference (track 4) → meter bus (track 5)
Then:
- Set the master bus, print track and meter bus to input monitoring.
- Put your meters on the meter bus.
- Put a maximizer at the end of the master bus, so you can hear decisions at roughly the final loudness.
- Begin mastering.
Housekeeping
- Match the session sample rate to the premaster to avoid unnecessary conversion.
- Name everything - the client, song, version and date.
- Save versions as you go, and keep notes of settings for revisions.
Do this now
- Build this five-track session template in your DAW and save it.
- Load a premaster and a reference, and confirm that switching between them shows both on the meter bus.
- Print a pass of the unprocessed premaster and check that it is identical to the original - a null test (flip the polarity of one and play them together) should be silent.
Adapted, with thanks, from the lesson notes of J.M. Brooklyn Audio Mastering.