Mastering Fundamentals: What Mastering Actually Does

Mastering has a reputation as either mysterious black magic or "just making it loud." Neither is true — here's what actually happens in a proper mastering pass.

Mastering is the final stage between a finished mix and a released track. Done well, it's subtle: a good master doesn't reinvent the mix, it polishes it and prepares it to translate consistently across every playback system a listener might use — earbuds, car speakers, club systems, laptop speakers, all of it.

What mastering is not

Mastering is not a fix for a broken mix. If the balance is off, if elements are masking each other, if the arrangement doesn't work — no amount of mastering processing corrects that. Mastering works on the mix as a whole; it can't isolate and fix an individual element the way mixing can. A common and expensive mistake is trying to "fix it in mastering" — problems that belong in the mix stage should be fixed there.

What a mastering pass typically includes

• Overall tonal balance. Broad, gentle EQ moves across the entire mix — not surgical fixes, but an overall tilt if the mix leans too dark, too bright, too bass-heavy, and so on.
• Dynamics control. Gentle compression or multiband compression to add cohesion and glue across the full mix, tightening how the elements sit together as a whole.
• Stereo width adjustments. Subtle widening or narrowing, usually applied carefully to avoid introducing phase problems — see our guide on stereo correlation and phase issues for why this matters.
• Loudness targeting. Bringing the track to an appropriate integrated LUFS level for its genre and intended platforms — see our guide on LUFS and loudness for the details.
• True peak limiting. A final limiter stage to control the loudest peaks and keep true peak at a safe level (commonly around -1 dBTP) for clean conversion to lossy streaming formats.
• Format preparation. Ensuring the final file meets the technical spec (sample rate, bit depth, file format) required by the distributor or platform.

Mastering for streaming vs. mastering "loud"

The instinct to master as loud as possible is largely a holdover from a pre-streaming-normalization era. Since platforms now turn overly loud masters down to their own target loudness anyway, pushing far past a reasonable loudness level mostly just costs dynamic range for no perceptual benefit at playback. See our full guide on streaming loudness normalization for exactly how this works platform by platform.

Should you master your own music?

There's no universal answer — it depends on your ears, your monitoring environment, and your budget. A few honest considerations:

• Fresh ears matter. After hours mixing a track, it's genuinely difficult to hear it objectively enough to master it well the same day. Stepping away, even overnight, helps.
• Reference tracks are essential if you're self-mastering — without a loudness-matched comparison in your genre, it's very easy to lose perspective on what "right" even sounds like.
• A second opinion helps, whether that's a professional mastering engineer, a trusted collaborator, or a tool that gives you an objective technical read on where your master actually stands.