Fabfilter Pro-Q 3: EQ Polarity and Output Boost

Fabfilter Pro-Q 3 Try it →Watch full video →

FabFilter·Jun 2026

Demo summary

The demonstration shows toggling auto gain, inverting polarity, and using the temporary 6dB output boost button to check channel clarity.

Step-by-step

Toggle the Auto Gain feature in the bottom bar
Click the Invert Polarity button if phase correction is needed
Hold the 6dB boost button at the top of the interface to temporarily increase output gain
Release the button to return to the original gain level

Options

Use the temporary boost on the last plugin in the chain for overall clarity checks
Use the temporary boost before a compressor to drive the signal harder

Tips

Use the 6dB boost to verify if a track needs EQ processing or simply a volume adjustment
Use the boost to identify which elements of other tracks are being occluded by the current channel
Look for the boost feature at the top of the UI, as it is easily missed by new users

Highlights

“this is a really simple, but in my opinion, very thoughtful and helpful feature”

All demos from “Mixing with the Pro-Q 4 Instance List”

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 Pro-Q 3· AI Mastering
3:361:26Adjusting Dynamics and Gain ParametersThe narrator demonstrates adjusting threshold, ratio, and gain structure across Pro-DS, Pro-G, and Pro-C 2 instances directly from the list view.Fabfilter Pro-Q 3· AI Audio Editor
5:231:08EQ Polarity and Output BoostCurrentThe demonstration shows toggling auto gain, inverting polarity, and using the temporary 6dB output boost button to check channel clarity.Fabfilter Pro-Q 3· AI Audio Editor
6:311:12Editing EQ Nodes and BandsThe narrator shows how to drag EQ nodes, adjust Q values, change filter types, and solo specific bands within the Pro-Q 4 instance view.Fabfilter Pro-Q 3· AI Audio Editor
14:170:59Frequency Collision DetectionThe demo shows setting a bass guitar as a collision reference to identify and fix frequency masking in rhythm guitars using a high-pass filter.Fabfilter Pro-Q 3· AI Audio Editor
Watch “Mixing with the Pro-Q 4 Instance List” →

AI Audio Editor

3:361:26Adjusting Dynamics and Gain ParametersThe narrator demonstrates adjusting threshold, ratio, and gain structure across Pro-DS, Pro-G, and Pro-C 2 instances directly from the list view.FabFilter
5:231:08EQ Polarity and Output BoostCurrentThe demonstration shows toggling auto gain, inverting polarity, and using the temporary 6dB output boost button to check channel clarity.FabFilter
6:311:12Editing EQ Nodes and BandsThe narrator shows how to drag EQ nodes, adjust Q values, change filter types, and solo specific bands within the Pro-Q 4 instance view.FabFilter
14:170:59Frequency Collision DetectionThe demo shows setting a bass guitar as a collision reference to identify and fix frequency masking in rhythm guitars using a high-pass filter.FabFilter
2:160:55Applying Spectral EQ with FabFilter Pro-Q 4The presenter demonstrates how to use the new spectral mode in Pro-Q 4 to lift the vocal presence while simultaneously taming harsh frequencies, similar to the functionality of Soothe.Streaky
3:111:21Dynamic EQ and Mid-Side processing in Pro-Q 4The user performs a side-channel cut to mono the bass and applies a dynamic EQ boost to the kick drum so it only triggers when the kick hits.Streaky
5:560:25Taming low-mids with Spectral EQThe user demonstrates applying spectral EQ around 300Hz to manage low-mid resonance and improve the feel of the track.Streaky
2:581:04Testing phase modes in Pro-Q 4The user switches between Zero Latency, Natural Phase, and Linear Phase modes in both FabFilter plugins while phase-inverted to see if any residue appears during playback.MixbusTv
4:162:03Comparing shelf and notch filters in Pro-Q 3 and 4The demonstration continues by applying low shelves at 120Hz, bell filters, and high-frequency notches to both plugins to verify they still null perfectly under different filter types.MixbusTv
0:161:10Notching out frequencies with FabFilter Pro-Q3Matty demonstrates how to identify and remove 'muddy' frequencies around 500Hz in a vocal track using the notch filter and solo audition mode in Pro-Q3.Matty Harris | MixAndMasterMySong
4:570:53Creating a filtered delay effectMatty uses steep low and high-cut filters in Pro-Q3 to isolate a specific frequency range for a parallel slap delay effect on a vocal track.Matty Harris | MixAndMasterMySong
7:100:48Broad stroke EQ for mix presenceThe demo shows using a wide Q setting to boost the brightness of a sample in real-time, helping it cut through a dense mix.Matty Harris | MixAndMasterMySong