Key takeaways
Mastering is the last polish on a finished stereo mix: small EQ moves, gentle compression and a limiter that sets the final level.
Start from a mix that peaks around -6 to -3 dBFS with no limiter on the master bus, exported as a 24-bit or 32-bit float WAV.
Compare against two or three commercial reference tracks at matched loudness, and check the master on headphones, a phone and a car.
About -14 LUFS integrated with a true-peak ceiling of -1 dBTP suits most streaming. Spotify plays its default setting at -14 LUFS and turns louder masters down.
A free DAW, a free loudness meter and the stock plugins are enough to start; AI mastering services are quick for demos.
What mastering does
Mixing balances the individual tracks of a song: vocals against drums, bass against guitars. Mastering works on the finished stereo file. It fixes small tonal problems, adds a little glue, sets the final loudness and makes sure the song sounds consistent with your other releases and with what plays before and after it.
A good master can't rescue a bad mix. If the vocal is buried or the bass booms, go back to the mix and fix it there.
What you need
A DAW. GarageBand is free on Apple devices, Reaper offers a free evaluation and an inexpensive license and Logic Pro and Ableton Live include capable stock EQs, compressors and limiters.
A loudness meter. The free version of Youlean Loudness Meter shows integrated loudness, true peak and loudness range and never expires. Pro adds streaming presets for $49.
Monitors or good headphones. See our guide to studio monitors for home producers.
Two or three reference tracks in a similar style that you know sound right.
Step 1: Prepare the mix
1. Take any limiter or loudness maximizer off the master bus.
2. Turn the mix down until its loudest peaks sit around -6 to -3 dBFS. That leaves the mastering chain room to work.
3. Export the mix as a WAV at the session's sample rate, in 24-bit or 32-bit float. Don't add dither and don't convert the sample rate yet.
4. Leave a second or two of silence before and after the song, so you can trim fades cleanly later.
5. Start a new project for mastering, so you can't fiddle with the mix while you master.
Step 2: Set up to listen accurately
Your room affects what you hear more than your speakers do. Put the monitors at ear height, in an equal triangle with your head, away from the wall behind them. Bass traps and a rug help a bare room.
Listen at a moderate level, around 75 to 85 dB SPL; a free SPL meter app on your phone gets you close enough. Louder sounds better, which is the trap: turn everything up and every change sounds like an improvement.
Load your reference tracks into the mastering project and turn them down to roughly the loudness of your mix, so you're comparing tone and balance at equal volume.
Step 3: Fix problems with corrective EQ
Start with EQ that removes problems:
High-pass filter around 20 to 30 Hz to remove rumble you can't hear but that eats headroom.
Narrow cuts for anything that rings or honks, such as a resonant room note in the low mids. Sweep a narrow boost to find it, then cut it by a few decibels.
If a problem needs more than about 3 dB of EQ, it belongs in the mix.
Step 4: Shape the tone
Now compare with your references. Is the song duller, boomier or thinner? Use wide, gentle EQ moves of about 1 to 2 dB: a little more air above 10 kHz, a little less mud around 200 to 400 Hz. Switch the EQ on and off at matched levels to check the change is an improvement at the same level.
Step 5: Add gentle compression
A bus compressor glues the mix together. Typical mastering settings:
Setting | Starting point |
|---|---|
Ratio | 1.5:1 to 2:1 |
Gain reduction | 1 to 2 dB on the loudest parts |
Attack | Slow, around 10 to 30 ms, so drum hits stay punchy |
Release | Auto, or medium |
If you can clearly hear the compressor pumping, back it off. A touch of saturation here adds warmth; keep it subtle.
Step 6: Check the stereo width
Keep everything below about 100 to 150 Hz in mono, so bass and kick stay solid on any system. Widen the top end only a little, if at all. Then switch your monitoring to mono: if the vocal or snare drops away, the mix has phase problems to fix before release.
Step 7: Set loudness with a limiter
The limiter goes last. It catches peaks so you can raise the overall level.
1. Set the output ceiling to -1 dBTP (true peak), so the file doesn't distort when streaming services convert it to compressed formats.
2. Raise the input gain while watching the integrated loudness on your meter.
3. Stop when the limiter is catching only peaks, typically 1 to 3 dB of gain reduction, or when you reach your target.
What loudness should you aim for? Spotify's default Normal setting plays music at -14 LUFS integrated, its Loud setting at -11 and Quiet at -19. Spotify advises keeping true peak below -1 dBTP, or below -2 dBTP for masters louder than -14 LUFS. Most other streaming services normalize to a similar level, around -14 to -16 LUFS.
You don't have to hit -14 exactly. A louder master is turned down, so pushing it harder costs you dynamics without making it louder on the service. For dense rock or electronic music, -10 to -8 LUFS is common; acoustic and jazz often sit quieter. Match your references.
Step 8: Compare, then take a break
Level-match your master against the original mix and the references and listen through the whole song. Then stop for a few hours or a day. Ears adapt quickly, and a fresh listen catches harsh highs or heavy bass that sounded fine an hour ago.
Check the master on headphones, cheap earbuds, a phone speaker and a car. If one problem shows up everywhere, fix it; if it shows up on one system only, leave it.
Step 9: Export the master
For distribution: most distributors accept a 16-bit, 44.1 kHz WAV, and many also take 24-bit. Check your distributor's own spec.
Dither: add it only when you reduce bit depth, such as 24-bit to 16-bit, and make it the very last step.
Keep a high-resolution master: save a 24-bit WAV at the session rate for future uses, such as hi-res stores or a vinyl cut.
Trim and fade: trim the silence and fade the ends cleanly so the song starts on time.
AI mastering services
Online AI mastering analyzes your mix and returns a master in minutes. BandLab Mastering is free, with four free presets. LANDR and eMastered let you upload a track and hear a preview before paying, and their subscriptions cover regular releases. They're handy for demos, quick social posts and a second opinion on your own master, but they give you less control than doing it yourself, and they can't fix problems in the mix.
When to hire a mastering engineer
Hire an engineer for a release you're paying to promote, or when you've lost perspective on your room or the mix. An engineer brings an accurate room and a fresh set of ears. Prices vary widely, so ask for a sample master of one song before you commit to an album.
Frequently asked questions
What LUFS should I master to?
About -14 LUFS integrated with a -1 dBTP true-peak ceiling suits most streaming, since Spotify's default setting plays at -14 LUFS. Louder masters are turned down, so match your genre's references.
Can I master with headphones?
Yes, if you compare against reference tracks and check the master on speakers, a phone and a car. Headphones exaggerate stereo width and make bass harder to judge, so be cautious with low-end and width changes.
Is AI mastering any good?
AI mastering services are fine for demos and social posts. For a release, a careful home master or an engineer usually does better.
What's the difference between mixing and mastering?
Mixing balances the separate tracks of a song into a stereo mix. Mastering works on that finished stereo file, adjusting tone, glue and loudness so it's ready for release and consistent with your other songs.
What true-peak ceiling should I use?
Set your limiter to -1 dBTP. Spotify recommends below -2 dBTP if your master is louder than -14 LUFS integrated, because converting a very loud file to a compressed format can push peaks over 0 dB.
What file format should I export for mastering?
Export the mix as a 24-bit or 32-bit float WAV at the session's sample rate, with no limiter or dither. Deliver the final master as a WAV in the format your distributor asks for, usually 16-bit, 44.1 kHz.