What is mastering?
Mastering is the last step between a mix and the world. In music it is the stage where an album's tracks are balanced against each other, brought to a consistent loudness and prepared for each release format. In film and advertising it is the equivalent step for the soundtrack: the finished mix is checked against the loudness and technical specifications of each destination (broadcast, streaming, cinema, social, podcast) and a compliant master is produced for each.
It is a job of measurement as much as taste. Broadcasters and platforms specify loudness in standardized units, true peak limits and sometimes dynamic range, and a master that misses those numbers gets rejected or, on a streaming platform, turned down automatically so that it plays quieter than everything around it.
Why it matters
Why mastering matters
Consistency is the audience's experience. A spot that is louder than the program it interrupts is annoying; one that is quieter disappears. A podcast whose episodes vary in level makes listeners reach for the volume. Mastering is what makes a brand's sound reliable across every placement, so the film plays at the same perceived level on a television, a laptop and a phone.
It is also where delivery either passes or fails. Broadcast networks run automated loudness checks and bounce anything outside spec, and a rejected master on the day of a campaign launch is a problem that mastering exists to prevent. The master is the last place anyone can catch a click, a dropout or a stray channel of silence before it airs.
In practice
How mastering works in practice
- 01
The mix engineer delivers a final mix, usually at a reference level with headroom. The mastering engineer listens through on calibrated monitors, measures the loudness and the peaks, and applies the small adjustments the material needs: a touch of EQ to translate across playback systems, limiting to control peaks, and gain to hit the target loudness for each destination.
- 02
Each deliverable gets its own master. A broadcast version at the network's standard, a streaming version at the platform's standard, a social version mixed slightly forward for small speakers, a stereo and a surround where required, plus stems if the client needs to re-version later. Every file is labeled, checked and logged, because mastering is the point where the sound becomes the deliverable.
At RIOT
Mastering at RIOT
Real Life, Worry Free, our CTV spot for Bogg Bags, is the kind of deliverable where mastering is not optional: connected TV platforms specify loudness and peak limits, and the spot has to meet them to run. The same discipline applies to everything we deliver for broadcast and streaming, where the master is the file that gets measured before anyone watches it.
Watch out
What people get wrong about mastering
Confusing loud with good. Pushing a master to the limit so it sounds bigger than the competition is a habit left over from radio, and streaming platforms now normalize loudness, which means an over-limited master simply plays with less dynamic range than a well-judged one. The other mistake is skipping it because the mix sounds fine. A mix that sounds fine in the studio has not been measured against a spec, and specs are what delivery is checked against.
