January 13, 2021 by Ian Stewart

Audio Mastering: When Is a Track Done?

Learn how to gauge the technical and aesthetic requirements for calling a track "done" during audio mastering, from the perspective of a mastering engineer.

It isn’t easy to know when to call a track done. Wherever you are in the creative process—arranging, producing, recording, or mixing—the temptation to try just one more thing or to make just one element a bit better is hard to resist. In audio mastering, the stakes are even higher than in mixing, as calling a track done when mastering means it’s really, truly done, done, and the result is what the world will hear.

If this isn’t something you do regularly, the pressure and decision-fatigue associated with that knowledge can be paralyzing. A solid gameplan can be your greatest asset when it comes to drawing a line in the sand, sticking a fork in it, and calling it done. So let’s dive in, figure out how to draw up that gameplan in the first place, and discuss what considerations we should keep in mind to successfully get a song, or album, across the finish line.

Stop, collaborate, and listen (critically, and with a project-specific listening checklist)

Careful, thorough, and attentive listening should always be your first port of call, whether you’re mastering music you've produced or mixed, or working on something for a friend or client. First impressions are vital during mastering, but so is an understanding of the musical journey conveyed by a song or album, along with the artistic intent that accompanies it.

To make the most of your initial listen, it can be incredibly helpful to take notes. If you’ve got a mind like a steel trap or if you’re working on a single, a mental list may suffice. But if you’re working on an EP or album, or if you struggle to remember what you ate for breakfast (like I do), written notes can be invaluable. 

Ask yourself the following questions

  • Tonal balance: Are there any frequency ranges that are overly pronounced or deficient? Notate this in a way that makes the most sense to you. Maybe that means writing “slightly boxy-sounding,” or maybe you’re a frequency ninja and can jot down, “slight cut at 380 Hz.”
  • Dynamics: Are there any elements that are jumping out too much? Is there too little or too much contrast between different sections of the song? Maybe you want to remind yourself to “automate chorus level up 1 dB,” or to think about “slightly pokey high percussion.”
  • Big-picture elements: On an EP or album, how do songs flow into and relate to one another? Are there contrasts that need to be maintained, accentuated, or reduced? Is there artistic, lyrical, or emotional messaging that runs counter to your tonal balance or dynamics notes?

Generating a list in this fashion not only gives you actionable items to work on as you dig into the processing portion of mastering the project, but it also keeps you from going down a rabbit hole, saves you time from working on minutiae that would be counter to the big picture, and lets you know when you’re done.

The caveat here is that you need to be able to trust your first listen—and your notes. If you’re working on your own music, taking some time away, or working on another song can help give you the objectivity you need to trust yourself. Having a good set of reference tracks which outline the borders of the sound you’re going for—a bright one, a dark one, a loud one, a dynamic one—can also be helpful in building confidence and self-trust.

Standard technical checklist for your mastering projects

Of course, mastering is not only a creative discipline but also a technical one. That means ensuring the finished files you create meet the technical requirements for the intended distribution platform, and more. To make this easier, especially if it’s not something you do every day, it can be helpful to have a standard technical checklist in addition to the project-specific notes we discussed above.

Here are some high-level categories to get you thinking along the right lines:

  • Final QC: Give all the files destined for distribution a final, detailed listen on headphones. This is your final safety net to make sure no unintended artifacts—clicks, pops, dropouts, truncated fades, too much or little silence between songs, etc.—sneak through.
  • Platform-specific levels: While I certainly don’t advocate trying to match normalization reference levels, it’s good to be aware of what may happen to your songs once they’re distributed. I’m not going to suggest specific numbers since reference levels and normalization methods change. However, tools like Loudness Penalty can help avoid unwelcome surprises.
  • Peak levels: We can dream of a day when lossless streaming is the norm rather than the exception, but in the meantime, it’s good to be aware of what the lossy codecs used by many streaming platforms can do to the peak levels of your tracks. The Codec Preview in  product-popover-icons-ozone.png Ozone  is your friend here, allowing you to audition—and adjust if desired—the effects of different codecs at different bitrates.

File formats: Knowing what sample rates, bit depths, and file types are accepted by the services you’re uploading to is also important in avoiding unexpected, post-upload changes. As a rule, 16-bit 44.1kHz .wav files are nearly universally accepted, although hi-res—24-bit at sample rates above 44.1k—files are accepted on sites like Bandcamp, and through select distribution channels. Music destined for video—BluRay or certain streaming services—may also have unique requirements. When in doubt, check with the service in question to see if they have specific technical guidelines.

Headphones commonly used for QC

Headphones commonly used for QC

Work through your project-specific and technical listening checklists

Now it’s time to work alongside your lists. As you begin processing your songs, working on tonal balance and dynamics, and generally enhancing the underlying emotion, refer back to your listening notes. Think about what you were hearing and feeling when you made those notes and work toward those goals.

If you find yourself getting stuck on any one step for too long, put it on the back-burner to work on the next item in the list. Remember that audio mastering is often an art of subtlety and conscious work not to overdo things. Try finding the least intrusive way to achieve the goals you’ve outlined in your listening notes.

Backtrack to any steps you’ve put on the back-burner, and continue to listen closely. If you reach the point where you’re only making the track sound different, and not better, you’re probably pretty close to being done.

Once you’ve worked through all those goals, checking boxes or crossing them off as you go, have a fresh listen all the way through the song. Don’t tweak any settings. Just sit, listen, and ask yourself if you’ve achieved the goals you previously outlined. Trust your earlier self, and that the notes you made were all that was required to achieve a satisfying listening experience.

A good way to verify that the changes you’ve made are satisfying your objectives is a quick, level-matched A/B test. Compare your finished master against the unmastered version of the track—but beware! It’s almost impossible to make a fair comparison if you haven’t level-matched the two versions. The Gain Match feature in  product-popover-icons-ozone.png Ozone  makes this a snap, but you can also do it manually or with a variety of other tools.

Once you’ve completed this process for all the songs in your project, you’re ready to work through your technical checklist and call it a day!

The takeaways

If you’re new to mastering, some of this may seem easier said than done, and that’s really where the trust element comes in. It’s imperative that you trust not only your earlier self that wrote the listening notes, but also your monitoring system, your intuition about what was needed for the music in the first place, and your ability to listen objectively.

All these things require practice. If you can, find a colleague whose taste you trust, and trade mixes and masters. Offer to master their mixes if they master yours. Compare notes and give each other feedback on the final results. In time, that trust will come, and you’ll be putting that final stamp of approval on songs more and more easily, and quickly.

Good luck, and happy mastering!