Mastering Chain Plugin Order: The Science Behind the Signal Flow

The Mastering Signal Flow Question

"Should EQ go before or after compression in mastering?" The answer: it depends on your goal. But there's a scientifically-grounded default order that most mastering engineers follow. Understanding why helps you make informed decisions.

The Standard Mastering Chain Order

(1) Corrective/Subtractive EQ — remove problems first (resonances, muddiness, harshness). (2) Compression — control dynamics gently, typically 1-3dB reduction with slow attack. (3) Additive EQ — boost what's missing (air, warmth, presence) after compression so the compressor doesn't fight your boosts. (4) Saturation/Excitement — add harmonics and density. (5) Stereo Imaging — adjust width (be careful with mono compatibility). (6) Limiting — final level, true peak ceiling, the last thing in the chain.

Why This Order?

EQ before compression: the compressor reacts to the EQ'd signal. If you boost bass before a compressor, the compressor triggers on the bass — possibly not what you want. Subtractive EQ before compression means the compressor works on a cleaner signal. Additive EQ after compression means your boosts don't affect the compressor's behavior. Limiting last: any processing after the limiter can push levels above your ceiling, causing clipping.

When to Break the Rules

Multiband compression: often placed before broadband EQ if you're fixing specific frequency issues dynamically. Mid-side EQ: can go anywhere in the chain, but most mastering engineers place it after initial corrective EQ. Clipping before limiting: some engineers clip transients before the limiter for loudness — this goes between the final EQ/saturation and the limiter. Tape emulation at the end: some engineers put a tape plugin after limiting for "glue" — risky but can sound great if done subtly.

Gain Staging Through the Chain

Every plugin in the mastering chain should output at roughly the same level it received. If plugin A cuts 2dB, plugin B should not need to boost 2dB to compensate — fix the EQ decision instead. Use gain-matched bypass (most mastering-grade plugins have this) to compare before/after at equal loudness. Louder always sounds better — gain matching reveals whether you're actually improving the sound.