Glad to read the problem has rectified itself!
About ducking;
Ducking is a method of automatically getting a compressor to kick in when triggered by an external source that, itself, is not being compressed.
As an example; Imagine yourself in a wonderful shopping market, where wonderful Muzak hits from 1964 are attacking your very soul, urging you to be a good citizen and not to steal from the store....Sudenly, the manager's squeaky voice comes over the bull-horns, stating there is a spill in isle four and the police have been dispatched!
What happens when the manager comes on the system is that the muzak mutes downward in volume and pops back to its previous level via the magic of ducking!
Ducking uses a cue feed from the manager's microphone to go into your compressor's insert point to act as a trigger signal to get the muzak to mute downward in volume via the compressor's setting to gain reduce its signal.
Aren't you glad you asked?
Cheers!