Mastering Prep

A workflow for preparing your mix for mastering — or for self-mastering with measurement guidance. You’ll compare against references, match to genre targets, and run final quality checks.

When to use this

  • Your mix is finished and you’re preparing to master (or send to a mastering engineer)
  • You’re self-mastering and want objective guidance
  • You want to verify your master is competitive with commercial releases

Workflow Overview

1

Compare to genre profile

See how your mix stacks up against typical loudness, spectrum, and dynamics for your genre

2

A/B against a reference track

Compare your mix to a specific commercial release you admire

3

Get matching recommendations

Phantom suggests specific EQ, loudness, and width adjustments to close the gap

4

Apply processing and verify

Make changes based on recommendations, then measure to confirm improvement

5

Final quality check

Catch any remaining problems before the master goes out

Step 1: Compare to genre profile

Why: Before reaching for a reference track, check how your mix compares to genre norms. This gives you context for whether deviations are intentional artistic choices or unintentional oversights.

Prompt:

Compare my mix to a pop profile — how does it measure up in loudness, spectrum, and dynamics?

Phantom output:

Profile Comparison: mix-final.wav vs Pop profile

Loudness: Yours: -15.1 LUFS Target: -12 to -14 LUFS UNDER Peak: -2.3 dBTP Target: -1.0 dBTP min OK

Spectrum: Low end: +0.4 dB vs target OK Mids: +0.8 dB vs target OK Highs: -2.6 dB vs target (dark)

Dynamics: Range: 8.1 LU Target: 5-8 LU OK (edge) Crest: 10.2 dB Target: 6-10 dB OK (edge)

Stereo: Width: 0.68 Target: 0.6-0.8 OK

Overall match: 74% Issues: 2 (below target loudness, dark top end)

What to look for:

  • “UNDER” on loudness means you’ll need gain + limiting
  • “Dark” spectrum means the high end needs attention (shelf EQ or exciter)
  • Values at the “edge” of target ranges are worth monitoring but not necessarily fixing

Step 2: A/B against a reference track

Why: Genre profiles are averages. A specific reference track you admire gives you a concrete target for the sonic character you want.

Prompt:

Compare my mix at mix-final.wav against reference-track.wav — show me the detailed differences in spectrum, loudness, and width

Phantom output:

Reference Comparison Your file: mix-final.wav Reference: reference-track.wav

Loudness: Yours: -15.1 LUFS Reference: -12.4 LUFS Difference: -2.7 LUFS (yours is quieter)

Spectrum: Band comparison: Sub: -0.3 dB vs ref OK Low: +0.8 dB vs ref (slightly bass-heavy) Low-mid: +1.1 dB vs ref (boxy) High-mid: -0.9 dB vs ref (less forward) High: -2.1 dB vs ref (darker)

Dynamics: Crest: 10.2 dB Reference: 7.1 dB Difference: Yours is more dynamic (+3.1 dB crest)

Stereo: Width: 0.68 Reference: 0.78 Difference: Yours is narrower (-0.10)

Overall similarity: 68%

What to look for:

  • Loudness difference of 2.7 LUFS is significant — this will be addressed by the limiter
  • The reference is brighter (+2.1 dB in highs) and more forward (+0.9 dB high-mid)
  • Reference is wider (0.78 vs 0.68) and more compressed (crest 7.1 vs 10.2)

Step 3: Get matching recommendations

Why: Now that you see the differences, let Phantom suggest specific processing to close the gap. These are starting points — you’ll adjust to taste.

Prompt:

Give me specific EQ, loudness, and width recommendations to match my mix closer to the reference

Phantom output:

Match to Reference: mix-final.wav -> reference-track.wav

Spectral Matching: Suggested EQ curve: +1.8 dB shelf at 10 kHz (add air/brightness) -1.0 dB bell at 350 Hz, Q=1.5 (reduce boxiness) +0.8 dB bell at 4 kHz, Q=1.8 (add presence)

Loudness Matching: Current: -15.1 LUFS Target: -12.4 LUFS Gain needed: +2.7 dB (apply before limiter) Limiter ceiling: -1.0 dBTP recommended

Width Matching: Current: 0.68 Target: 0.78 Suggestion: +15% stereo widening above 2 kHz Keep sub-200 Hz in mono

Confidence: 81%

How to apply:

  1. Add a mastering EQ with the suggested curve (shelves first, then bells)
  2. Add gain before your limiter
  3. Set limiter ceiling to -1.0 dBTP
  4. Apply subtle stereo widening in the upper frequencies
  5. Keep the low end mono (M/S EQ: narrow below 200 Hz)

Pro tip

Apply recommendations at 50-70% of suggested values first. A +1.8 dB shelf at 10 kHz? Start with +1.0 dB and listen. You can always add more, but it’s harder to undo over-processing after your ears adapt.

Step 4: Apply processing and verify

Why: After applying the mastering chain, measure again to confirm you moved in the right direction and didn’t introduce new problems.

Prompt:

I’ve applied the mastering EQ and limiter. Compare my master at mastered-v1.wav against the reference — did I close the gap?

Phantom output:

Reference Comparison (after mastering) Your file: mastered-v1.wav Reference: reference-track.wav

Loudness: Yours: -12.8 LUFS Reference: -12.4 LUFS Difference: -0.4 LUFS (very close)

Spectrum: Band comparison: Sub: -0.2 dB vs ref OK Low: +0.4 dB vs ref OK Low-mid: +0.3 dB vs ref OK (improved) High-mid: -0.2 dB vs ref OK (improved) High: -0.6 dB vs ref OK (improved, still slightly dark)

Overall similarity: 86% (was 68%)

Decision point: Similarity improved from 68% to 86%. The remaining differences (-0.6 dB in highs) are minor and may be intentional (your mix has a slightly warmer character). Decide if you want to push closer or accept.

Step 5: Final quality check

Why: Before declaring the master done, run problem detection to catch anything that the mastering processing might have introduced — particularly true peak violations and clipping from the limiter.

Prompt:

Run a final quality check on mastered-v1.wav — check for true peak violations, clipping, and any problems introduced by mastering

Phantom output:

Problem Detection: mastered-v1.wav Scanned: mastered-v1.wav (3:42, 44.1kHz/24bit, stereo)

Issues Found: 1

LOW True peak at -0.9 dBTP Two instances at 1:42 and 2:58 Suggestion: Lower limiter ceiling to -1.0 dBTP

No issues: clipping, DC offset, phase, hum, sibilance, mud, harshness, resonances

Overall: PASS (1 minor issue)

Final decision: One minor true peak issue at -0.9 dBTP (just barely over the -1.0 standard). Either lower the limiter ceiling by 0.1 dB, or accept it (some platforms allow up to -0.5 dBTP).

Pro tip

Always run the final check at high sensitivity. Better to catch a marginal true peak issue now than have a streaming platform apply its own limiting to your carefully crafted master.

Quick Reference

  1. Compare my mix to a [genre] profile — how does it measure up?
  2. Compare my mix against [reference] — show me the differences
  3. Give me specific EQ, loudness, and width recommendations to match the reference
  4. Compare my master against the reference — did I close the gap?
  5. Run a final quality check on [master] — check for problems

Next Steps