How to Prepare Your Mix for Mastering: A Step-by-Step Checklist

8 min read

You finished your mix. You're proud of it. Now you want it mastered — either by a mastering engineer, an online service, or your own mastering chain. But before you bounce the file and hit send, there's a checklist you need to run through. Skipping it is the most common reason masters come back sounding worse than the mix you sent.

Mastering can only work with what you give it. If your mix is clipping, muddy, or off-balance, mastering will magnify those problems — not fix them. This checklist covers everything you need to verify before exporting, from loudness targets and frequency balance to stereo width, dynamics, and file format. Run through it every time and your masters will sound better before the mastering engineer even touches a knob.

1. Check your overall loudness

Your mix should arrive at mastering with reasonable loudness — not already mastered. If your mix bus limiter is crushing peaks to -8 LUFS, the mastering engineer has no headroom to work. Aim for an integrated loudness between -18 and -14 LUFS, with peaks no higher than -3 dBTP.

This gives mastering room to process, adjust levels, and apply final limiting. If you've been mixing into a limiter, bypass it before exporting. The mix should sound dynamic, not competitively loud.

• Integrated LUFS: -18 to -14 LUFS
• True peak: no higher than -3 dBTP
• Remove master bus limiter before export (unless it's integral to the sound — discuss with your mastering engineer)

Not sure where your mix sits? Check it with a LUFS meter and compare against streaming platform specs to understand the target range.

2. Verify frequency balance

A balanced mix translates to a balanced master. If your low end is 6 dB too hot, the master will be boomy. If your highs are scooped, the master will sound dull. Mastering EQ is broad — it can't fix problems that should have been addressed track-by-track.

Use a spectral analyzer to check your frequency curve. A well-balanced mix has a smooth, natural slope from low to high, roughly following a pink noise contour. Red flag areas:

• 20–60Hz: Sub-bass energy that adds no musical value — high-pass if unnecessary.
• 200–500Hz: Mud buildup from guitars, keys, and bass. Read our guide to fixing a muddy mix for specifics.
• 2–5kHz: Harshness that will get worse when mastering adds loudness.
• 10–20kHz: Too little air = dull master. Too much = sibilant and fatiguing.

3. Confirm stereo width and mono compatibility

A mix that sounds wide on monitors can fall apart in mono. Phone speakers, Bluetooth speakers, club systems, and many streaming environments sum to mono — and if your mix has phase issues, elements will cancel out and disappear.

Before exporting, check your mix in mono. Listen for:

• Elements that vanish or get noticeably quieter when summed to mono — they have phase issues.
• Low-frequency content (kick, bass, sub synths) that should be mono but is stereo — collapse it to mono.
• Stereo width that's artificial — excessive Haas effect or stereo widenerson bus can cause issues.

For a detailed method, see our mono compatibility guide. Use a stereo analyzer to visualize your stereo field and correlation.

4. Check dynamics and crest factor

Mastering adds loudness — which reduces dynamics. If your mix is already heavily compressed, the master will be lifeless. A good mix should have a crest factor (difference between peak and average level) of at least 8–10 dB.

Signs your mix is over-compressed:

• The waveform looks like a brick — no variation in amplitude.
• Quiet sections are as loud as the chorus.
• The mix sounds louder but not punchier when you engage the master bus compressor.

Use the dynamic range calculator to measure your crest factor. If it's under 6 dB, go back and reduce compression on individual tracks. Read our compression basics guide for a refresher.

5. Match a reference track

Reference matching is the fastest way to know if your mix is in the ballpark. Import a professionally mixed and mastered track in a similar genre into your session. Match loudness (use a loudness matching plugin like MagicAB or ADPTR Metric AB) and compare:

1. Tonal balance: Does your mix have more or less low end? More mids? Brighter or darker?
2. Loudness: Where does your unmastered mix sit relative to the mastered reference? (It should be quieter — that's normal.)
3. Dynamics: Is your chorus hitting as hard as the reference, or is it compressed flat?
4. Stereo width: Is your stereo field as wide and controlled as the reference?

Reference matching isn't about copying — it's about calibrating your ears. Your monitors and room color what you hear, and a reference gives you a known anchor.

6. Fix any clipping or digital errors

Check every track for clipping — not just the master bus. Individual channel clipping can hide under the mix bus, and mastering will reveal it. Use a true peak meter on the master bus to catch inter-sample peaks that regular meters miss. See our true peak guide for why this matters.

Other issues to check:

• Clicks and pops from edits — crossfade all edit points.
• Silence at the start and end — leave 100–200ms of room tone before the first note and after the last decay.
• Noise floor — hiss, hum, or background noise that will become more audible after mastering gain.

7. Choose the right file format

Mastering should receive the highest quality file you can deliver. Lossy formats (MP3, AAC) discard audio data that mastering can't recover. Export your mix as:

• Format: WAV or AIFF (uncompressed PCM)
• Bit depth: 24-bit (or 32-bit float if your DAW supports it)
• Sample rate: Match your session (44.1, 48, 88.2, or 96 kHz). Don't upsample — it adds no real resolution.
• No dither if you're staying at 24-bit or higher. Dither only when reducing bit depth.
• No normalization — leave the level where it naturally sits.

If you're sending to an online mastering service, check their requirements — some accept 32-bit float, others prefer 24-bit. Never send an MP3 unless it's the only option.

8. Organize your deliverables

If you're sending to a human mastering engineer, make their job easy:

• Name files clearly: ArtistName_SongTitle_MIX.wav
• Include a text file with: tempo, key, sample rate, bit depth, and any notes (e.g., "vocal is intentionally dark," "don't add brightness to the hats").
• Export all songs in an album at the same sample rate and bit depth.
• Leave 1–2 seconds of silence at the start of each file.
• Remove any master bus processing that wasn't part of the creative mix decision.

9. Do a final A/B against your reference

Before you export, one last check. Match loudness to your reference track and switch between them. If your mix sounds noticeably worse at matched loudness, something's still off. Common culprits:

• Duller than reference: Check for mud masking highs, or a missing high-shelf boost.
• Thinner than reference: Low end is under-represented — boost bass or kick, or check for an accidental high-pass on the mix bus.
• Harsher than reference: Cut 2–5kHz on the offending tracks.
• Wider than reference: Your stereo width may be artificial. Narrow it and re-check mono compatibility.

10. Export and verify

After exporting, re-import the bounced file into a fresh DAW session. Check that it sounds identical to your mix, has no clipping, and has the correct sample rate and bit depth. This catches export errors that are easy to miss.

For the fastest verification, upload your mix to MixDiagnose. It checks loudness, frequency balance, dynamics, stereo width, and true peak in one pass — and tells you exactly what to fix before you spend money on mastering.

The checklist at a glance

1. Integrated loudness: -18 to -14 LUFS
2. True peak: no higher than -3 dBTP
3. Remove master bus limiter
4. Frequency balance: smooth, no mud or harshness
5. Mono compatibility: no elements disappear when summed
6. Crest factor: at least 8–10 dB
7. Reference match: tonal balance in the ballpark
8. No clipping, clicks, or noise floor issues
9. Export as 24-bit WAV at session sample rate
10. Re-import and verify the bounce

Run this checklist on every mix and your mastering results will improve immediately — regardless of who's doing the mastering.

For more, read our 10 signs your mix isn't ready for mastering and our loudness units guide to understand the numbers behind these targets.

Ready to find out what's actually wrong with your mix? Try MixDiagnose — free analysis, no signup required. See pricing for advanced features.

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