Duck EQ is an Equaliser that reacts to a side chain input, or in other words a Ducker that can act on specific frequencies.

DuckEQ’s integration of EQ means it can duck only specific frequency bands, as well as normal "broadband" ducking. Apart from ducking, there are many other applications that DuckEQ can be used, for example instead of ducking a signal, one could apply gain to the EQ bands and "EQ-Gate".