Fabfilter Pro-Q 3: Mix bus compression and Mid/Side sidechain EQ

Fabfilter Pro-Q 3 Try it →Watch full video →FabFilter · Jan 2026

Demo summary

The narrator demonstrates transparent glue using Smooth style and vintage character using Vari-Mu on a mix bus, including a technique to unlink stereo compression using a side-channel notch filter.

Step-by-step

Select a compression style such as Smooth for transparency or Vari-Mu for vintage character
Adjust the ratio and knee settings to control how the compressor hits the signal
Turn down the linking knob to experiment with unlinking the stereo compression
Listen to the sidechain signal
Add an EQ band and switch it to a steep notch filter
Widen the notch filter to remove the midrange frequencies
Set the EQ band to process only the side channel

Options

Use the Mastering style in the Utility section for a less refined glue
Apply Bright saturation or Tube character to complement the compression style
Toggle between transparent glue and fat vintage settings

Watch out for

Unlinking stereo compression can cause the stereo image to wander if wide-panned instruments are present

Tips

Ride the curve of a big soft knee rather than hitting the signal with the full ratio all the time
Use a side-channel notch filter to create compression that is stereo linked for the midrange but unlinked everywhere else

Highlights

“this one isn’t transparent, it's fat and vintage and glorious”

All demos from “Introduction to FabFilter Pro-C 3”

0:221:34Host-synced sidechain ducking in Pro-C 3The narrator demonstrates how to use the new Host Sync feature to create rhythmic ducking on a pad sound without an external trigger, adjusting threshold, ratio, and the new curvy Range slider.Fabfilter Pro-Q 3· AI Audio Editor
2:311:39MIDI triggering and Character saturation modesThe demo shows routing MIDI from a kick drum to trigger compression on a bass part, followed by a walkthrough of the new Tube and Diode saturation flavors in the Character tab.Fabfilter Pro-Q 3· AI Audio Editor
4:101:20Multiband processing with TTM style and Sidechain EQThe narrator applies the new TTM (To The Max) style to a drum bus and demonstrates the improved sidechain EQ with up to six bands to control frequency-specific compression thresholds.Fabfilter Pro-Q 3· AI Mastering
5:551:06Using Auto Threshold on guitar transientsThe demo shows the new Auto Threshold feature which allows the compressor to catch peaks relative to average levels, demonstrated on a guitar DI signal with Diode character saturation.Fabfilter Pro-Q 3· AI Audio Editor
7:462:16Multichannel linking and surround sidechain EQThe narrator demonstrates the new multichannel linking knob on an 8-channel drum setup, showing how to link or unlink specific channels and apply sidechain EQ to specific surround speakers.Fabfilter Pro-Q 3· AI Audio Editor
10:531:46Comparing Smooth, TTM, and Op-El stylesA side-by-side demonstration of the Smooth, TTM, and vintage Op-El compression styles on a drum bus to show different sonic textures and distortion levels.Fabfilter Pro-Q 3· AI Mastering
12:392:21Mix bus compression and Mid/Side sidechain EQCurrentThe narrator demonstrates transparent glue using Smooth style and vintage character using Vari-Mu on a mix bus, including a technique to unlink stereo compression using a side-channel notch filter.Fabfilter Pro-Q 3· AI Mastering
15:052:41Upward compression for stereo widthThe demo shows how to use the new Upward compression style on a pad sound's side channel to increase stereo width, while explaining the importance of the Range limit and lookahead.Fabfilter Pro-Q 3· AI Mastering
Watch “Introduction to FabFilter Pro-C 3” →

AI Mastering

4:101:20Multiband processing with TTM style and Sidechain EQThe narrator applies the new TTM (To The Max) style to a drum bus and demonstrates the improved sidechain EQ with up to six bands to control frequency-specific compression thresholds.FabFilter
10:531:46Comparing Smooth, TTM, and Op-El stylesA side-by-side demonstration of the Smooth, TTM, and vintage Op-El compression styles on a drum bus to show different sonic textures and distortion levels.FabFilter
12:392:21Mix bus compression and Mid/Side sidechain EQCurrentThe narrator demonstrates transparent glue using Smooth style and vintage character using Vari-Mu on a mix bus, including a technique to unlink stereo compression using a side-channel notch filter.FabFilter
15:052:41Upward compression for stereo widthThe demo shows how to use the new Upward compression style on a pad sound's side channel to increase stereo width, while explaining the importance of the Range limit and lookahead.FabFilter
5:050:51Widening guitars with Dynamic High ShelvesThe presenter applies a dynamic high shelf boost to the side channels at 16kHz to add movement and width to the guitars.Streaky
2:430:53Using EQ Match in the Instance ListThe demo shows how to access the EQ Match feature within the Instance List to match the frequency profile of a rhythm guitar track to a reference track.FabFilter