Many DAW’s comes bundled with a generic de-esser. De-esser’s simply compresses the “S” sound in vocals. The goal with a de-esser is to make the “S” sound smoother and less harsh to the listener.
Some vocalist do pronounce their S’s more than others and for this reason we need to fix that in the mix.
In the video below, I’m going to demonstrate how you can create a simple de-esser using a compressor. I am using Logic’s stock compressor however this can be done with any compressor.
For your convenience, download this preset for logics compressor (you can use this as a starting point):