Logic’s new DeEsser 2 is a frequency specific compressor, designed to compress a particular frequency range within a complex audio signal. Its main job is to reduce sibilance in vocals, although it can be useful on cymbal and drum drum overhead mics as well. What makes this update so special is the addition of the new “relative” threshold mode.
Rather than reacting to a fixed (absolute) threshold, the amount of DeEssing applied is adjusted dynamically based on how much the signal detected by the Split Frequency Band differs from the input signal. So in practice, we set the threshold level, so it is identifying the sibilance based the range we set with either the Split or Wideband detection modes. Then when the level of the sibilance rises and falls within the audio signal, the threshold is adjusted automatically so that the same amount of DeEssing is applied, regardless of how loud the detected sibilance is.
Relative threshold mode makes getting a natural and even sounding response from the DeEsser so much easier. Check out this video to hear it in action.