MD: Mastering Chain (Full)

AI-generated audio almost always comes out of the sampler too quiet, too boomy, or with harsh digital top end. Fixing that used to mean exporting to a DAW. MasteringChainNode is the in-graph alternative: gain, filters, EQ, compression, and a limiter arranged in a proper mastering signal chain, all behind one node with a BEFORE/AFTER waveform comparison.

The chain order is the classic one, and the node follows it: input gain → highpass/lowpass cleanup → EQ (a high shelf plus three optional parametric bands) → compressor (single or multiband) → brickwall limiter last. That's a real mastering order - the limiter goes at the very end so nothing after it can push you back into clipping.

The stages that matter

• master_gain_db - input trim before processing. Leave at 0 unless the source is unusually quiet.
• Highpass/lowpass - the "cleanup" stage. enable_highpass with highpass_freq around 30Hz kills sub-mud; the lowpass (default off, 18kHz) trims harsh top end. *_order sets filter steepness.
• EQ - a eq_high_shelf for air, an optional low shelf, and four parametric bands (55Hz, 125Hz, 1.25kHz, 5kHz defaults) with gain, frequency, and Q. You don't need all four - enable the ones that matter and leave the rest off.
• Compressor - enable_comp toggles it. comp_type is the important choice: Multiband (default) compresses low/mid/high independently with per-band threshold/ratio/attack/release/makeup, which is what mastering actually wants; Single-Band is the blunt instrument. Crossover points at 250Hz and 4kHz split the bands.
• Limiter - enable_limiter, recommended true, limiter_ceiling_db at -0.1dB by default so peaks never clip.

Everything is toggled by an enable_* switch rather than a value of zero, which is genuinely nicer than the alternative - it means "off" is truly off and you can A/B a stage without remembering its original settings.

Outputs

audio (the mastered waveform - same AUDIO format in, AUDIO format out, so it chains into a save/preview node), plus waveform_before and waveform_after as IMAGE plots. Wire those two into a comparer and you can see what the chain actually did without listening to a single export.

Installing it

Part of MD Nodes (MDMAchine/ComfyUI_MD_Nodes). ComfyUI Manager → search MD_Nodes → Install, restart, or:

cd path/to/ComfyUI/custom_nodes
git clone https://github.com/MDMAchine/ComfyUI_MD_Nodes.git
cd ComfyUI_MD_Nodes
pip install -r requirements.txt

The audio DSP here leans on pedalboard (the README lists it among the audio requirements), and the waveform plots need matplotlib. Both are in the requirements file. Python 3.10+, current ComfyUI.

Common issues

The author's own launch post warned this node "can take a bit to process" - it's doing real DSP per sample, so long tracks plus multiband compression can be slow; expect a wait, not a hang. If you push master_gain_db positive and enable the limiter, the limiter just eats the headroom - set the chain up so the limiter's ceiling is the loudest thing you allow. And if the output sounds lifeless, check whether you've enabled more compression bands than you need; a -10dB threshold across all three bands is a lot of glue.