Each path is filtered to restrict its frequency range, then sent into a compressor or expander.Ī dynamic EQ applies the gain reduction/expansion to the gain parameter of a parametric equaliser which processes the original input signal. They both split the input signal into multiple parallel paths. Multi-band compressors/expanders and dynamic EQs work in a similar way. Typical multi-band dynamics processors work to some extent, but with inconvenient downsides. Automation is only convenient when the spectral changes occur over a long period of time, and aren't repetitive.

The two most common solutions are automation and multi-band dynamics processing. This is often undesirable! For example, a presence boost which was appropriate during one section of a performance may become harsh during another section. However, the equalisation applied is usually static - it remains the same over time. Equalisation is the audio engineer's most widely used processing tool.