Multiband compressor

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The Axe-Fx UltraTM contains a three-band compressor that is great for mastering or compression of a whole mix. It also works great after distortion to help thicken the tone. The basic principle of the Multi-Band compressor is that the input is divided into three bands using a crossover. Compression is applied to the individual bands and then the outputs recombined. This allows isolating bands of the input material and applying different amounts of compression. Multi-Band compression is the de-facto mastering tool and can really improve the final mix.


  • FREQ1 - Sets the crossover frequency between band 1 and band 2.
  • FREQ2 - Sets the crossover frequency between band 2 and band 3. Each compressor section has it’s own menu page with the following paramters:
  • THRSH - Threshold control. The threshold at which output compression starts to occur.
  • RATIO - Sets the gain reduction ratio. This is the ratio of input power to output power beyond the threshold. For example, if the threshold is -40 dB, the input signal is -30 dB and the ratio is 2.0 the output will be -35 dB.
  • ATT - Attack rate. Sets how fast the compressor reduces its gain once the threshold is exceeded. Higher values equal faster response.
  • REL - Release rate. Sets how fast the compressor restores the gain once the signal has fallen below the threshold.
  • LEVEL - Sets the output level of the band.
  • DET - Selects the type of detector to use, RMS or Peak.
  • MUTE - Mutes the output of the band. You can use the mute controls to audition one or more bands.