How it works
Five stages, in this order, every time.
Each stage depends on the measurement taken by the one before it.
-
Upload the mix
A stereo mix, bounced without a limiter on the master bus if you have the choice. Nothing is re-encoded on the way in, so a 24-bit 96 kHz WAV is analysed as a 24-bit 96 kHz WAV.
Accepts wav aiff flac mp3 Length up to 20 minutes
-
Measure what came in
Before anything is changed, the mix is measured: integrated loudness, true peak, loudness range and spectral balance. That measurement is kept and shown beside the finished file, labelled as the input, so you can see what moved.
A master and a mix are never shown as one unlabelled number. A −20 LUFS mix cut to −14 that still read “−20.0 LUFS” would tell you nothing happened.
Measures integrated LUFS · true peak · range · tilt
-
Match to a genre reference
You pick a genre and the mix is matched to a finished master in that genre. Matching corrects tonal balance and stereo width toward that reference while leaving the arrangement alone.
There are five genres because there are five references good enough to hand a track to. A sixth button would promise a target that does not exist.
Genres pop rock hip-hop electronic acoustic
-
Render to the delivery target
Loudness is brought to the target you chose and the true-peak ceiling is enforced on the way out. Three files are written: the 24-bit master at your source sample rate, a 16-bit 44.1 kHz version, and an MP3 at 320 kbps.
Scrolls sideways →
Preset Loudness Ceiling Notes streaming −14.0 LUFS −1.0 dBTP Source sample rate, 24-bit loud-11 −11.0 LUFS −1.0 dBTP Above the streaming target, still codec-safe loud-95 −9.5 LUFS −1.0 dBTP Modern commercial loudness loud-8 −8.0 LUFS −1.0 dBTP Loud; the limiter does real work streaming-tp20 −14.0 LUFS −2.0 dBTP The −2.0 dBTP ceiling is Spotify’s own recommendation once a master is louder than −14 LUFS: a harder-limited master has more samples near the ceiling, so more of them overshoot when it is encoded. It is a column, not the default — ours is −9.5 / −1.0, which trades that guidance for the peak room a punchier master needs. loud-11-tp20 −11.0 LUFS −2.0 dBTP loud-95-tp20 −9.5 LUFS −2.0 dBTP loud-8-tp20 −8.0 LUFS −2.0 dBTP streaming-tp01 −14.0 LUFS −0.1 dBTP The −0.1 dBTP ceiling is for files that are never re-encoded. AES TD1008 §4 recommends not exceeding −1 dBTP at the input of a lossy encoder, and §7 notes the threshold should drop further as bitrate falls — so these four are the wrong choice for anything you upload. loud-11-tp01 −11.0 LUFS −0.1 dBTP loud-95-tp01 −9.5 LUFS −0.1 dBTP loud-8-tp01 −8.0 LUFS −0.1 dBTP apple −16.0 LUFS −1.0 dBTP Apple Digital Masters club −7.0 LUFS −0.5 dBTP Loud systems cd −9.0 LUFS −0.3 dBTP 16-bit 44.1 kHz vinyl peak-normalised −1.0 dBTP No limiter; lows summed below 120 Hz -
Measure the file that will be delivered
The rendered file is measured again, and checked against what mastering actually achieved rather than against the wish. That catches a botched resample or a corrupted render, which a check aimed only at the target number would let through.
If the mix could not reach the target without passing the ceiling, the file is still delivered — at the loudest level that stays compliant — with the shortfall stated in LU. The ceiling is never traded away, because the ceiling is the reason the target was out of reach.
Two measurements
Two measurements.
Every finished job carries two sets of numbers. Mixing them up is the most expensive mistake a mastering interface can make, so they are always labelled.
What arrived. Useful for judging the mix — whether it has headroom, whether it is already squashed, whether the low end is carrying more than its share.
What you are about to download. This is the number that matters for release, and it is measured on the actual rendered file, not predicted from the settings.
Specifications
What goes in, and what comes out.
- WAV, AIFF, FLAC, MP3
- Up to 20 minutes
- Stereo mixes; sample rate and bit depth preserved
- 24-bit WAV at the source rate
- 16-bit 44.1 kHz WAV
- MP3 320 kbps
- pop, rock, hip-hop, electronic, acoustic
- Each one a finished commercial master
- Picked per job, not per account
Questions
Questions about the chain
How long does a master take?
Most tracks finish in 2–10 minutes. The five stages run in the same order every time.
Do I have to pick a delivery target?
No. The default is −9.5 LUFS at a −1.0 dBTP ceiling, which is what most of this catalogue would have chosen. The full matrix is there if you want a different one.
What happens if my mix cannot reach the target?
It delivers what it reached without breaching the ceiling, and states the shortfall on the job page. The ceiling is never traded for loudness.
Which numbers am I looking at?
Two sets. One is measured on the file as it arrived, before anything was touched; the other on the file you download. They are labelled separately everywhere they appear.
Can I run the same track again?
Yes, at a different target or against a different reference. The preview is free every time. On Unlimited the new master is included; per track, each master you download is its own purchase.
What can I upload?
WAV, AIFF, FLAC or MP3, up to 1 GB and 20 minutes. You get 24-bit WAV, 16-bit WAV and MP3 320 back on every paid level.
The same chain, every track
The same five stages on every track.
Start with a track you already know.
The preview is free and full length, and level-matched against your original, so you can hear what changed rather than what got louder.