Esoteric dynamics defined
A standard compressor will bring down the level of a signal once that signal has passed the threshold. Another term for this is downward compression – in other words, the dynamic range is being compressed by bringing louder parts of the signal downward. Sure, we usually just call it ‘compression’, but the distinction becomes useful when you encounter something called upward compression.
Upward compression again leaves us with a lower dynamic range in our signal, only here it’s done by bringing the quietest parts upward in level when they’re below a certain threshold. In FabFilter’s Pro-MB, for example, this is achieved by increasing the Range parameter to a positive value while in compression mode. Now add two other concepts to the equation: upward expansion and downward
expansion. If you can’t guess, downward expansion means that signals below the threshold are reduced, thereby expanding the dynamic range of a signal – this is what we tend to mean when we talk about expansion in general. Upward
expansion, therefore, would be increasing the loudest signals above a certain threshold in order to expand the dynamic range.
A multiband compressor consists of multiple compressors split into different frequency bands, allowing high frequencies, mid frequencies, bass frequencies and sub bass frequencies to be compressed using different settings. These frequency bands themselves are usually set as required, depending on the material at hand.
Dynamic EQ, on the other hand, allows you to set up EQ cuts and boosts whose gain controls are reactive to the signal levels within those bands. Depending on the specific dynamic EQ, bands can compress or expand the audio material. This is useful for making EQ cuts to harsh frequencies only when those frequencies are too harsh, and not at other times.
The best examples of frequency-conscious dynamics are in traditional de-essers, where the detection circuit of a compressor is band-passed at just the ‘ss’ frequencies, so that the compressor only reacts to those frequencies when they’re too harsh. Using a modern frequencyconscious compressor, you can use one band of frequencies to trigger compression over an entirely different frequency range, for creative results.