Mastering: EQ and dynamics

Principles

In mastering you work on the whole mix at once: every move touches all the instruments in that region. That is why you use small, broad moves (0.25–2 dB, Q 0.5–1.5), prefer clean or high-quality color tools, and listen at a constant level with loudness-matched comparison. If a correction is needed for a single instrument (sibilant vocal, kick too loud), the best solution is to go back to the mix or work on the stems.

EQ in mastering

Corrective

• HP: 20–30 Hz, 12–18 dB/oct, only to remove rumble and offset; in genres with sub (trap, EDM) at 18–22 Hz or none.
• Mix resonances: narrow cut (Q 3–6) of 1–2 dB on a peak that sticks out in the spectrum and is heard as a "hum" or a note that sounds louder.
• Mud: 200–400 Hz −0.5/−1.5 dB, Q 0.7–1.
• Harshness: 2–5 kHz −0.5/−1.5 dB, often with dynamic EQ (acts only during loud passages).
• Residual sibilance: de-esser in mastering at 6–9 kHz, 1–2 dB, preferably on the Mid only.

Color

• Air: high shelf or Baxandall +0.5/+1.5 dB at 10–16 kHz (Pultec 12–16 kHz with wide bandwidth, Maag Air Band).
• Weight: low shelf +0.5/+1 dB at 30–60 Hz (Pultec 30 or 60 Hz with the boost+atten trick).
• Presence: broad bell +0.5/+1 dB at 2–4 kHz if the mix is muffled (with care).
• Tilt: ±0.5–1 dB around 700 Hz–1 kHz to balance dark/bright.

Linear or minimum phase?

• Linear phase: for moves on the bass and on M/S without phase rotation; watch out for pre-ringing (softened kick transients) with narrow boosts/cuts in the bass.
• Minimum phase / analog: for color and broad moves; it sounds more "natural" and punchy.
• M/S: HP on the Side at 100–150 Hz; high shelf on the Side +0.5/+1 dB; slight cut on the Mid at 300 Hz if the center is muddy; slight boost on the Mid at 1–3 kHz to bring the vocal forward.

Dynamics in mastering

Wideband compression (glue)

• Ratio 1.2:1–2:1; attack 10–30 ms (to let transients through); release auto or 100–300 ms (tempo-synced); soft knee; GR 0.5–2 dB; HP filter in the sidechain at 60–120 Hz so the kick doesn't make the mix pump.
• Types: VCA (SSL, Shadow Hills, API 2500), vari-mu (Manley), opto (rare), transparent digital (Kotelnikov, Pro-C 2 Mastering).
• Parallel: stronger compression (3–6 dB) blended in at 20–40% for density without losing the peaks (Pro-C 2 mix, Maximus).

Multiband

• Three or four bands: < 120 Hz, 120 Hz–1 kHz, 1–5 kHz, > 5 kHz. Use only the bands you need.
• Bass: control of the low end that grows in the chorus (ratio 1.5–2:1, attack 20–40 ms, release 150–300 ms, GR 1–2 dB).
• Upper mids: harshness in loud passages (ratio 1.5–2:1, attack 5–15 ms, release 80–150 ms, GR 0.5–1.5 dB).
• Highs: sibilance and cymbals (ratio 2:1, attack 1–5 ms, release 50–100 ms, GR 1 dB).
• Linear (FIR) crossovers for maximum transparency.

Dynamic EQ

Often preferable to multiband: it acts on a narrow band only above the threshold. Examples: 2.5–3.5 kHz −1/−2 dB when the vocal shouts in the chorus; 60–80 Hz −1/−2 dB when kick and 808 add up; 7 kHz −1/−2 dB on sibilance.

Upward compression and expansion

• Light upward compression (Ozone, Pro-MB, Waves MV2): +1/+2 dB in quiet passages for density (with caution: it brings up noise and tails).
• Upward expansion of transients (Ozone Dynamics, transient shaper on the master): recovers punch in over-compressed mixes; 0.5–1.5 dB.

Order

1. Corrective EQ → 2. corrective dynamics (dynamic EQ/multiband) → 3. glue → 4. color EQ → 5. saturation → 6. stereo → 7. clipper → 8. limiter. Variations: color EQ before the compressor if you want the compressor to react to the added air (more "glue" on the highs).

Starting settings by genre

When to go back to the mix

• You need more than 3 dB of EQ in one region.
• A single instrument causes the problem (vocal, kick, 808, cymbals).
• Corrective dynamics are working all the time (not just intermittently).
• The low end changes a lot between the 808's notes (a sound design problem).

Common mistakes

• Lots of small boosts that add up to +4 dB in one region.
• Compression with a fast attack: loss of punch.
• Multiband on every band "just in case".
• Linear-phase EQ with narrow boosts in the bass (pre-ringing).
• Judging without level matching.

How to hear it

• Bypass at equal loudness every 2–3 changes.
• Listen to the master at low volume: if the vocal and kick stay clear and the bass remains present, the tonal balance holds up.