From "Compression Uncompressed":
"[Multi-band compressors] can come in handy for sibilance control, also known as “de-essing”. Sibilance can come in starting anywhere above 5kHz for a male vocal (or Kathleen Turner) and 6kHz for a female vocal (or Frankie Valli.), but typically has a rather narrow bandwidth where it does come in. We do not want to scoop out too much of the spectrum on the high end here; we can adversely affect vocal and acoustic instrument clarity and presence, cymbals and hi-hats, and overall mix “air” and clarity if we mess with too many of the high frequencies.
"For this reason it’s a good idea to use a middle band on the MBC for sibilance control instead of the highest band; the highest band on a typical MBC does not have an upper crossover or boundary setting, it just goes all the way to 20kHz or more, so we cannot narrow our net on the upper end with that band. A middle band (band 2 on a 3-band or band 2 or 3 on a 4-band) has crossovers or boundaries on both sides so we could use one of those to attack just the sibilance only and leave the crisp air above it alone.
"Once we have our band picked, set both the lower and upper boundaries of that band to about 5kHz, and turn the band’s output gain up temporarily, just to boost the eventual volume of signals within that band’s coverage. Then slowly sweep the frequencies between 5kHz and 10kHz with the upper crossover or boundary setting until you hear the volume of the sibilance be boosted by the output gain. Make sure you have all the sibilance boosted, but that you don’t go beyond that point. Now you have the upper range of that band set.
"Now sweep in the same manner with the lower crossover boundary. When the volume of the sibilance just starts decreasing, you’ve found the lower end of the sibilance and you leave your low end of the MBC band there. Then return the Output Level for that band to normal. Because sibilance is a high frequency (fast wave form) phenomenon, fast attack times are usually necessary. Set release times as needed for the vocalist. Then you can apply the needed compression with the threshold and gain reduction settings. Those settings are entirely dependant upon the dynamics of the recorded content; use as needed, but never more than you need"
G.
