Now let me begin by saying that I have not upgraded to Pro Tools 10, which solves this little problem with something they call “clip based gain”, but if you use any version of Pro Tools before 10 or another program like Logic Pro, Ableton, Reaper or whathaveyou, you can use this trick.
The problem: When you want to compress a track that varies wildly in it’s volume, it becomes hard to set the compressor so that the sound doesn’t get over-compressed when the original audio is loud and under-compressed when the original audio is quiet. Unfortunately “automating” the fader for the track only affects the output of the track, which is after the compressor and so it does nothing to help alleviate the problem.
The solution: My “trim” plugin trick. The real issue is that the volume feeding the compressor is going from too far below the threshold to too far above the threshold. What I do to rectify this is insert a “trim” (or “gain” in other programs) plugin before the compressor. This allows me to do any make-up gain using automation of the “trim” plug-in, which in turn stabilizes the volume going into the compressor and keeps it in a nicer range giving you a more subtle compression. This also allows the volume for the track to be separately automated.
The Vocal (green) audio track has some jumps in volume. Below it is the automation lane for the “Trim” plugin on the vocal track. Needless to say, the compressor doesn’t work so hard and the vocal sounds much cleaner this way.