Configure FFmpeg Superequalizer Band Gains

This article explains how to configure the 18-band superequalizer audio filter in FFmpeg. You will learn the syntax of the filter, the specific frequency bands it controls, how the gain values work, and practical command-line examples to boost or cut specific audio frequencies.

Understanding the Superequalizer Filter

The superequalizer is a high-fidelity, 18-band graphic equalizer filter in FFmpeg. Unlike standard equalizers that use decibel (dB) values, the superequalizer uses amplification factors (multipliers) to adjust the volume of each frequency band.

The 18 Frequency Bands

The filter splits the audio spectrum into 18 fixed, logarithmically-spaced frequency bands:

1. 65 Hz (Sub-bass)
2. 92 Hz (Sub-bass)
3. 131 Hz (Bass)
4. 185 Hz (Bass)
5. 263 Hz (Low-mids)
6. 373 Hz (Low-mids)
7. 529 Hz (Mids)
8. 750 Hz (Mids)
9. 1063 Hz (Mids)
10. 1506 Hz (High-mids)
11. 2133 Hz (High-mids)
12. 3022 Hz (Presence)
13. 4280 Hz (Presence)
14. 6061 Hz (Brilliance)
15. 8585 Hz (Brilliance)
16. 12159 Hz (Treble)
17. 17222 Hz (Treble)
18. 24391 Hz (Ultra-high / Inaudible)

Filter Syntax and Gain Values

The filter accepts a single parameter called gains, which is a space-separated list of 18 decimal numbers enclosed in single quotes.

-af "superequalizer=gains='g1 g2 g3 ... g18'"

How Gain Values Work:

• 1.0: Unity gain (no change to the volume of this band). This is the default.
• 0.0: Complete attenuation (mutes the band entirely).
• 2.0: Doubles the amplitude of the band (approx. +6 dB boost).
• Allowed Range: Each value must be between 0.0 and 20.0.

Practical Examples

1. Default (Flat) Equalizer

To run the filter without changing any frequencies, set all 18 values to 1:

ffmpeg -i input.mp3 -af "superequalizer=gains='1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1'" output.mp3

2. Bass Boost

To boost the lower frequencies (65 Hz to 185 Hz) while keeping the mid and high frequencies untouched, increase the first four values:

ffmpeg -i input.mp3 -af "superequalizer=gains='1.8 1.8 1.5 1.5 1 1 1 1 1 1 1 1 1 1 1 1 1 1'" output.mp3

3. Treble Boost / Vocal Clarity

To make vocals pop and increase brightness, boost the presence and treble ranges (approx. 3 kHz to 12 kHz) while leaving the bass flat:

ffmpeg -i input.mp3 -af "superequalizer=gains='1 1 1 1 1 1 1 1 1 1 1.2 1.5 1.8 1.8 1.5 1.2 1 1'" output.mp3

4. Low-Cut (High-Pass) Filter

To reduce muddy low-end rumble (cutting frequencies below 131 Hz), lower the first three values:

ffmpeg -i input.mp3 -af "superequalizer=gains='0.1 0.2 0.5 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1'" output.mp3