What should you send to a mastering studio?

The file: uncompressed, at the native resolution

For stereo mastering we recommend an uncompressed WAV or AIFF file, ideally at the project's native resolution and sample rate. 24 bit or 32 bit float is perfectly fine.

The important word is « native ». Resampling or reducing the resolution before sending gains nothing and removes material: send us the file exactly as your project produces it.

Item	What we recommend	Why
Format	uncompressed WAV or AIFF	a compressed format has already lost information, permanently
Resolution	24 bit or 32 bit float	headroom to work without hitting the noise floor
Sample rate	the project's native rate	an unnecessary resample is one more conversion
Clipping	none	clipping is irreversible; mastering does not repair it

The master bus: we do not ask you to strip everything

This is the most commonly misunderstood point. We do not systematically ask for all master bus processing to be removed. Compression, saturation or any other processing that is part of the sound you are after can perfectly well stay in place.

Where a limiter is used mainly to raise the level, however, it is better to also send us a less limited or unlimited version. That lets us compare the two, preserve the artistic intent, and keep more latitude for the mastering.

Key point

The distinction is not « processed or unprocessed », it is intent. Processing that shapes the sound stays. Processing that only raises the level costs us latitude: in that case, send both versions.

Stems: case by case, not by default

For classic stereo mastering, stems are not needed. They become useful when separate treatment of certain groups is genuinely required. We therefore ask for them case by case, after listening, rather than up front.

Headroom before mastering: no universal rule

There is no universal rule requiring a specific amount of headroom, such as −6 dBFS, before mastering. What matters is that the mix is clean, unclipped and representative of the sound you want.

The principle that covers all of the above

The most important thing is to send us the best mix you have artistically approved, without trying to pre-empt the mastering. A mix « prepared for mastering » at the expense of your own choices is a bad trade.

On the loudness question, which often leads to limiting too early, see why a louder master does not necessarily sound louder on streaming. The most frequent questions are gathered in our FAQ.