How the course works
Read a lesson, then try it on a song you know well. The practice tool is OBRA Audio Mastering: drop in a mix and it shows every move a master makes, with its number, so you can see each lesson happen. It runs in your browser and 2 different songs a day are free, with no account.
- 8lessons, about 5 minutes each
- −14 LUFSthe median loudness of 3,082 real mixes dropped into OBRA (October 2026)
- −1 dBTPthe true-peak ceiling for streaming
Lesson 1 · Listen before you touch anything
Mastering starts with listening, not with plugins. Play your mix next to two finished songs of the same style, at the same loudness, on the system you know best. Write down three things: is it darker or brighter, is the low end bigger or smaller, does it feel wider or narrower.
- Match loudness first. A song 1 dB louder sounds better for a few seconds, and that fools everybody.
- Listen to the chorus and to the quietest part. Most problems hide in one of the two.
- Check in mono for a moment. If the vocal or the bass drops away, there is a phase problem in the mix.
Practise: OBRA's first stage does exactly this. It measures tone in sixth-octave bands, dynamics band by band, stereo, phase and true peaks, and shows you what it found.
Lesson 2 · Prepare the mix
Most bad masters start as a bad export. Fix this before anything else.
- Export a WAV at 24-bit or 32-bit float, at the session's sample rate. No MP3.
- Remove the limiter from the master bus. Leave peaks around −6 to −3 dBFS.
- Leave the fade-out and the reverb tail whole, with a little silence after.
- Do not chase loudness in the mix. In our study of 3,082 mixes, the median mix already sat at −14 LUFS integrated, and half were between −16 and −11 LUFS.
- FL Studio export: settings that matter
- Ableton Live export: option by option
- Logic Pro bounce: for mastering
- GarageBand export: without the hidden limiter
Lesson 3 · Tone: EQ with a light hand
Mastering EQ moves the whole song, so small moves matter. Think in decibels you can count on one hand.
- Cut before you boost. Find the one band that is too much (often 200 to 400 Hz mud, or harsh 2 to 5 kHz) and take 1 to 2 dB out.
- Use wide shapes. A shelf or a broad bell sounds like the song. A narrow boost sounds like a plugin.
- Compare with your references at equal loudness after every move.
- If you need more than about 3 dB anywhere, the problem is in the mix. Go back and fix it there.
Practise: OBRA compares your tone with how professional masters of its style sound and evens it out with up to 8 bands, cuts first. Open the Studio and turn its EQ off and on to hear what it did.
Lesson 4 · Dynamics: compression and multiband
A master compressor should hold the song together, not squash it. Aim for 1 to 2 dB of gain reduction on the loudest parts, with a slow-ish attack so the hits still come through.
- Bus compression glues the mix: low ratio (1.5:1 to 2:1), 1 to 2 dB of reduction.
- Multiband compression keeps one band steady when it jumps, like a bass that booms on some notes. Gentle, and only where it is needed.
- A transient shaper brings drums forward without raising the level.
- Watch the peak-to-loudness ratio (PLR). The median mix in our study had a PLR of 13 dB; dense genres go under 9.
Practise: in the Studio, OBRA's multiband stage has four bands. Watch its gain reduction history while the chorus plays.
Lesson 5 · Stereo: wide on top, mono below
Width sells a master, until it breaks on a phone. Keep the bass and kick in mono, and open only the upper range.
- Low end in mono below about 120 to 150 Hz, so it hits on phones, cars and club systems.
- Open the image a little above that if the mix feels narrow. A little goes a long way.
- Check the correlation meter. It should stay well above zero; near zero or negative means parts of the song cancel in mono.
Practise: OBRA opens the image above 140 Hz and keeps the bass in mono. Switch its stereo stage off in the Studio to hear the difference.
Lesson 6 · Loudness: LUFS targets
Streaming services play music at a reference level and turn louder songs down. A louder master is not louder for the listener, only denser.
| Where it goes | Plays at about | Peak ceiling |
|---|---|---|
| Spotify, YouTube, Tidal | −14 LUFS | −1 dBTP |
| Deezer | −15 LUFS | −1 dBTP |
| Apple Music | −16 LUFS | −1 dBTP |
| Club and DJ | no normalization, often around −9 LUFS | −0.3 dBTP |
- Acoustic, jazz, classical, film: about −16 to −14 LUFS.
- Most pop, hip-hop, R&B and rock: about −12 to −9 LUFS.
- EDM, trap and metal: about −9 to −7 LUFS when density is the style.
- LUFS for Spotify, Apple Music and YouTube: every platform in one table
- How loud to master for Spotify: the −14 LUFS reference explained
Lesson 7 · Limiting and true peak
The limiter is the last thing in the chain. It sets the final level and catches the peaks.
- Use a true-peak limiter with the ceiling at −1 dBTP for streaming, or −2 dBTP for very loud masters.
- Push it until it changes the sound, then back off 1 dB. If the kick loses its punch, you went too far.
- Measure the exported file. Dither, sample-rate conversion and the export itself change the true peak.
- Export 24-bit for distribution. 16-bit / 44.1 kHz only if a CD or a store asks for it, with dither.
Practise: OBRA's last stage is a clipper and a true-peak limiter with 16x oversampling, measured on the file you download.
Lesson 8 · Compare, decide, deliver
- Make two or three versions: one that breathes, one in between, one dense.
- Compare them with your mix and your references at the same loudness.
- Listen on headphones, a phone speaker and a car before you decide.
- Pick the one that serves the song, not the loudest one.
- Deliver a 24-bit WAV, write down its LUFS and true peak, and keep your unmastered mix.
Practise: OBRA gives you three masters, Natural, OBRA and Loud, at the same loudness, and its Platforms view plays each one the way Spotify, Apple Music and YouTube will.
After the course
2 different songs a day free, with no account: all three masters, the Studio and every meter, as a WAV or FLAC up to 24-bit / 48 kHz. Each extra song is a one-off $3 / €3 / £3 (unlimited downloads of that song for 30 days, 88.2 / 96 kHz and 32-bit float included), or unlimited with OBRA PRO, $10 / €10 / £10 a month.
- Mixing vs mastering: which problems belong to which step
- How to master an album: order, loudness and gaps across a record
- How loud is independent music in 2026?: 3,082 mixes measured
If the mix itself needs work, a person can help where a master cannot. OBRA ULTRA is mixing and mastering by an OBRA engineer: you send your tracks and get a WAV and a written note back, $19 / €19 / £19 per round, within 72 hours. Spots are limited each week.
Frequently asked questions
Is this mastering course really free?
Yes. The eight lessons are free to read, with no account, and the practice tool masters 2 different songs a day free in your browser.
How long does it take to learn mastering?
The basics fit in an afternoon: listening at equal loudness, gentle EQ, light compression, mono bass and a true-peak limiter. Hearing small differences takes months of practice on many songs, which is why the course asks you to practise each lesson.
Do I need expensive plugins to master a song?
No. The stock EQ, compressor and limiter of any DAW can make a good master. A true-peak limiter and a LUFS meter matter most. OBRA's free LUFS meter and mastering tool run in the browser.
What LUFS should I master to?
Streaming services play at about −14 LUFS (Apple Music about −16) and turn louder songs down. Quiet genres sit around −16 to −14 LUFS, most pop and hip-hop around −12 to −9, and dense club genres around −9 to −7. Keep true peaks at −1 dBTP.
Can I master my own song?
Yes, with fresh ears and references. Take a break after mixing, compare at equal loudness and check on several systems. If you cannot be objective about a song, a second pair of ears helps.
What is the difference between mixing and mastering?
Mixing balances the tracks of a song against each other. Mastering treats the finished stereo mix as one piece: tone, dynamics, width and loudness for release.