Most of the advice about mastering focuses on individual tools: which compressor to use, how much EQ to add, what limiter is best. But before any of that matters, you need to know what order those tools go in and why. Put them in the wrong order and each plugin will be working against the one before it.
This post is part of the Complete Guide to Audio Mastering.
Why Order Matters in Mastering
Every processor in a mastering chain changes the signal before passing it to the next one. A compressor reacts to the tonal balance of what it receives. An EQ shapes the frequencies that the limiter will then catch. If you put a limiter before a compressor, the compressor will try to control a signal that has already been limited, which produces strange and often unpleasant results.
The order of processing is not a rigid rule with no flexibility. Some engineers swap steps based on the specific needs of a project. But the standard order exists for good reasons, and it is the right starting point for most situations.
The Chain, in Order
1. High-Pass Filter (Optional)
Start with a high-pass filter if the mix has low-frequency rumble or sub-bass buildup that was not addressed during mixing. Set it below the lowest useful frequency in the mix. For most music, anything below 20 to 30 Hz can be safely removed without affecting the sound.
This step reduces the amount of energy that all subsequent processors have to deal with in the low end, which results in cleaner, more controlled compression and limiting.
2. EQ (Corrective)
The first EQ in a mastering chain is for correction. This means fixing problems: removing a frequency buildup in the low-mids, taming harshness in the upper mids, or smoothing a slightly uneven tonal balance. The moves are small, usually 0.5 to 2 dB, and the Q settings are wide.
This comes before compression because the compressor should react to a signal that already has the right tonal balance. If you compress first and then EQ, you are shaping a signal that has already had its dynamics altered, which can produce unnatural results.
3. Compression
Mastering compression is light. The goal is not to dramatically control dynamics the way you would on a vocal track. It is to add subtle glue, slightly raise the average loudness, and give the master a sense of cohesion and control.
Typical settings: ratio 1.5:1 to 2:1, slow attack (40 to 80 ms), program-dependent release, 1 to 3 dB of gain reduction. The compressor should feel almost invisible. If you can clearly hear it working, it is probably doing too much.
See Mastering Compression Settings for detailed settings and cheat sheets.
4. EQ (Tonal)
A second EQ after compression is used for tonal shaping rather than correction. This is where you add the final polish: a gentle high shelf boost for brightness and air, a small low shelf boost for warmth, or a slight presence boost to make the master feel more forward and alive.
This EQ sits after compression so it shapes the sound of the compressed signal. The character of the compressor becomes part of the tonal foundation that the second EQ builds on.
5. Stereo Widening (Optional)
Subtle mid/side processing can be used to add a small amount of width to the master. A common approach is to boost the high frequencies slightly in the side channel to add air and stereo dimension without introducing phase issues. This must be checked in mono. Any adjustment that causes audible phase cancellation in mono needs to be reduced or removed.
6. Saturation (Optional)
Tape emulation or harmonic saturation can be added at this stage for warmth and analog character. Keep it subtle. The goal is for the saturation to feel like a quality to the master rather than an obvious effect. 1 to 2 dB of harmonic enhancement is usually more than enough.
7. Limiting
The limiter is always last. It catches any peaks that would exceed the output ceiling and brings the overall loudness up to the target level. A good limiter does this transparently, preserving the feel and energy of the master while preventing clipping.
Set your output ceiling to -1 dBTP (true peak) to prevent inter-sample distortion during playback. Aim for your target integrated LUFS level (typically -14 LUFS for streaming). See What is LUFS? for the full breakdown of loudness targets.
What About Multiband Compression?
Multiband compression is sometimes used in mastering chains, usually placed between the broadband compressor and the EQ or between the two EQ stages. It should be used only when there is a specific frequency-dependent dynamic problem that a standard compressor cannot fix cleanly. Most masters do not need it. When in doubt, leave it out.
A Note on Flexible Chains
The chain above is a starting point, not a fixed law. Some engineers prefer compression before corrective EQ when using the compressor specifically as a tone-shaping tool. Some prefer to put a clipper before the limiter to handle peaks more transparently at high loudness levels. Others use parallel compression at the mastering stage rather than inline compression.
What matters is that you understand why each tool goes where it does, so when you change the order, you are doing it with intention and a clear understanding of what will change as a result.