The order of operations
Modern record-making has four stages: writing, tracking, mixing, mastering. Each builds on the last:
- Writing — the song is composed (chords, melody, lyrics).
- Tracking — each instrument is recorded as a separate audio track.
- Mixing — the engineer balances the individual tracks into one cohesive stereo mix.
- Mastering — the mastering engineer polishes the stereo mix and makes the album sound consistent.
What mixing does
A mix engineer works inside a single song. The toolkit covers volume balance (vocal in front, drums punching through, bass anchoring the bottom), EQ (removing muddiness, brightening the vocal, carving room for each element), compression (evening out dynamics), reverb and delay (space and depth), panning (distributing elements across the stereo field), and automation (changing all of the above over time as the song evolves).
A finished mix is one stereo file — the song as it will be heard, but not yet competition-loud or album-consistent.
What mastering does
A mastering engineer works on the finished mix. They never adjust individual tracks — only the stereo file. The toolkit:
- Loudness — bring the track up to streaming-platform LUFS targets without losing dynamics.
- EQ — micro-adjustments to balance against industry references and other tracks on the same album.
- Multiband compression — even out frequencies that move differently (e.g. a kick that gets louder during the chorus).
- Stereo enhancement — widen or narrow the stereo image as appropriate.
- Limiting — set the true-peak ceiling so streaming codecs don't clip.
- Album sequencing — make sure track 4 leads cleanly into track 5, with consistent loudness.
- Format delivery — render in the right format for each platform (24-bit WAV for distributors, MFiT-AAC for Apple, etc).
Can a single person do both?
Yes — and increasingly, they do. Bedroom producers routinely mix and master their own tracks. The advantage: one creative vision throughout. The disadvantage: ear fatigue. Spending 3 hours mixing and then immediately mastering the same song means you've lost objectivity.
Best practice for self-mixing-and-mastering: separate sessions, ideally a day apart. Reset your ears, listen on different speakers, reference against commercial tracks in your genre.
Frequently asked
Can I master without mixing first?
You can, but the master will only be as good as the mix it starts from. "Mastering can't fix a bad mix" is a real engineering rule.
Do streaming services need a mastered file?
They accept any file but normalise it to platform-standard LUFS. A track that isn't mastered to compete will sound noticeably quieter and less polished alongside competitors.
How much does professional mastering cost?
$50-300 per song for indie engineers, $500-2,000 for mastering rooms with vintage hardware. AI mastering services (LANDR, Cloudbounce, Bandlab) start at $5-15 per song.