Before you send a mix to be mastered, or before you master it yourself, there are specific things that need to be in place.
Skipping these steps does not just make the mastering engineer’s job harder.
It can lead to a final master that is louder but worse, or one that sounds good on your speakers but falls apart everywhere else.
This post is part of the Complete Guide to Audio Mastering.
Why Mix Prep for Mastering Matters
Mastering is not a repair stage. It is a refinement stage.
The mastering chain takes what is already a good mix and brings out its best qualities while preparing it for distribution.
If the mix has balance problems, phase issues, or clipping on the master bus, no amount of mastering will fix them cleanly.
Getting the mix ready for mastering starts with a few technical requirements and a few decision-making steps that affect everything that follows.
Step 1: Remove All Limiting and Heavy Clipping From the Master Bus
This is the most important step and the one most often missed by beginners.
If you have been mixing with a limiter on your master bus to keep the playback level high and comfortable, that limiter needs to come off before you export for mastering.
Mastering engineers need headroom to work with. If the limiter has already been clipping the mix and flattening transients, the mastering chain cannot undo that damage.
The master will end up sounding loud but lifeless because the dynamics were already destroyed before mastering began.
The exception is a very gentle brickwall limiter used only for safety during the mix session to prevent clipping.
That kind of limiter, if used lightly, causes less damage. But even then, it is worth removing before exporting.
Step 2: Leave Headroom
Export your mix with the master bus peaking no higher than -3 to -6 dBFS. Some engineers recommend -6 dBFS, others say -3 dBFS is fine.
The key point is that the mix should not be hitting 0 dBFS or clipping at any point in the file.
The mastering chain, especially the limiter at the end of it, needs room to bring the loudness up. If the mix is already at 0 dBFS, the mastering chain has nowhere to go.
If your mix peaks at around -4 to -6 dBFS with no limiter, you are in a good place.
Headroom is not just about peak level. It is also about dynamic headroom, which is what mastering engineers actually use to push loudness without crushing transients. A pre-master mix should land at around 12 to 14 dB of crest factor. If yours is already sitting at 8 dB, you have done the mastering engineer’s job for them, usually not in a good way.
Step 3: Check for Clipping on Individual Tracks
Clipping on individual tracks within the mix is invisible at the master bus level. A mix can have multiple clipped elements that, when combined, still read below 0 dBFS at the output.
But the distortion from those clipped tracks is already baked into the audio.
Check each channel strip and make sure nothing is overloading before it reaches the mix bus. This is a gain staging problem that is fixed during mixing, not mastering.
Step 4: Check Phase and Mono Compatibility
Before exporting for mastering, fold your mix down to mono and listen. If elements disappear, get significantly quieter, or sound wrong in mono, you have phase problems.
These will not be fixed in mastering. Go back to the mix and address them.
See Mono vs Stereo: The Complete Guide for how to check and fix mono compatibility issues.
Step 5: Verify the Low End
Low-end decisions are harder to fix in mastering than in mixing. A mastering EQ cut at 100 Hz affects the kick, the bass, the room, and everything else at once.
In mixing, you can address each element separately.
Before sending the mix out, check the low end on at least two different playback systems. Check on headphones and on small speakers.
If the bass is overwhelming on small speakers, or completely absent, the mix needs adjusting before mastering.
See How to Make Your Mix Sound Good on All Speakers.
Step 6: Export at the Right Format
Export your mix as a WAV or AIFF file at the same bit depth and sample rate it was recorded at. The most common formats are 24-bit, 44.1 kHz, or 48 kHz.
Do not convert or dither before sending to mastering.
Let the mastering engineer handle the final dithering when they output the master at 16-bit for distribution.
Never export the mix as an MP3 before mastering. MP3 compression removes audio data permanently, and once that data is gone, mastering cannot add it back.
Step 7: Send a Reference Track
If you are working with a mastering engineer, always include a reference track from a commercially released song that represents the sound you are going for.
This removes a lot of guesswork and ensures the master matches your expectations for tone, loudness, and character.
Even if you are mastering yourself, loading a reference into your session before you start is one of the most effective things you can do to calibrate your decisions.
See How to Use Reference Tracks When Mixing.
Checklist Summary
- Remove all limiting and heavy clipping from the master bus
- Export with peaks between -3 and -6 dBFS
- Check all individual tracks for clipping
- Check the mix in mono before exporting
- Verify low-end balance on multiple systems
- Export as WAV or AIFF at original bit depth and sample rate
- Include a reference track
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