Multi-band Compressor

A multi-band compressor is both a volume- and a tone-based plug-in.

It is also another type of dynamics processor, and much like its cousin, the de-esser, it is used to control the dynamic range of a specified band or bands of the frequency spectrum, independent of one another. In a sense, a multi-band compressor is a cross between an EQ and a compressor.

In addition to all of the parameters of a single-band or traditional compressor, a multi-band compressor will have several parameters labeled “crossover.”

Measured in “Hz” or “kHz,” crossover determines where each band ends and the next begins. For instance, if the first “crossover” is set to 100 Hz, then the first band, which will be compressed independently of everything else within the frequency spectrum, will include all of the frequencies between 20 Hz and 100 Hz. The second band would then include all of the frequencies from 100 Hz up to the second “crossover,” wherever that might be. Multi-band compressors usually have 3 or 4 adjustable bands, but they can theoretically have any number of them.

Because I’m usually able to get my mix to where I want it with the use of basic tools, like EQ and compression, I rarely use a multi-band compressor. The low end of an overall mix, however, can be difficult to control, due to its susceptibility to “muddiness” and the fact that it attenuates less over distance than higher frequencies. I sometimes use a multi-band compressor on the master fader towards the end of a mix, which allows me to isolate everything below 100 Hz, for instance, and apply compression to those problem frequencies in order to control the low end without affecting the rest of the mix.