Multiband Compression Explained: The Complete Mastering Guide

Multiband Compression Explained: The Complete Guide

What is multiband compression?

Multiband compression is an audio processing technique where the signal is split into several frequency bands, and each band is compressed independently. This lets you control the dynamics of individual frequency ranges without touching the others.

Why do you need multiband compression?

The problem with a regular compressor

A regular (full-band) compressor reacts to the overall signal level. If the kick drum triggers it, the compressor squashes the entire signal — vocals and highs included. That can lead to:
- "Pumping" — an audible breathing of loudness
- Loss of clarity in the high end
- Uneven treatment of different frequency ranges

The solution: splitting into bands

A multiband compressor splits the signal into bands:
- Sub-bass (20–100 Hz) — kick drum, sub bass synths
- Low-mids (100–800 Hz) — bass guitar, piano
- Mids (800–5000 Hz) — vocals, guitars
- Highs (5000–20000 Hz) — cymbals, air, presence

Key parameters

Crossover frequencies

The frequencies at which the signal splits into bands. Magic Master uses:
- 100 Hz — separates sub-bass from the main bass range
- 800 Hz — separates low frequencies from mids
- 5000 Hz — separates mids from highs

Ratio (compression amount)

Determines how much the signal is compressed:
- 1:1 — no compression (bypass)
- 2:1 — gentle compression (jazz, classical)
- 4:1 — moderate compression (pop, rock)
- 8:1+ — heavy compression (EDM, hip-hop)

Knee

Determines how smooth the transition is between uncompressed and compressed signal:
- Hard knee — an abrupt transition (aggressive processing)
- Soft knee — a gradual transition (transparent processing)

Attack and release

• Attack — how quickly compression kicks in (fast = more transient control)
• Release — how quickly it lets go (fast = a more "alive" feel)

Upward compression

A special kind of compression where quiet signals are boosted instead (ratio below 1:1). This lets you:
- Bring out detail in quiet passages
- Increase perceived density
- Preserve peak levels without squashing them

Practical genre settings

EDM / Electronic

Sub-bass: ratio 3:1, threshold -18 dB
Mids: ratio 2:1, threshold -16 dB
Highs: ratio 2.5:1, threshold -14 dB
Upward: enabled on sub-bass

Rock / Metal

Sub-bass: ratio 2:1, threshold -16 dB
Mids: ratio 3:1, threshold -14 dB
Highs: ratio 2:1, threshold -12 dB
Upward: disabled

Jazz / Classical

All bands: ratio 1.5:1, threshold -20 dB
Soft knee: enabled
Upward: disabled

Podcast / Speech

Mids: ratio 3:1, threshold -16 dB (main processing)
Highs: ratio 1.5:1, threshold -14 dB
Upward: enabled on mids

How this works in Magic Master

Magic Master uses 4-band dynamics with:
- Adaptive ratio — scaled by genre preset
- Soft knee — 6 dB for transparent processing
- Upward compression — to bring out quiet detail
- Look-ahead limiter — on every band, for peak control
- Pedalboard (JUCE) — professional-grade compressor engine where available

Tips

1. Don't over-compress — excessive compression kills dynamics
2. Listen on multiple systems — what sounds great in headphones can fall apart on speakers
3. Use A/B comparison — keep comparing against the original
4. Watch your metering — LUFS, True Peak, stereo correlation

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Try multiband compression in Magic Master: magicmaster.pro/app