Frequency-Dependent Limiting Application: De-Essing
Some vocalists and announcers, especially if equalized for more treble, will produce excessive "sibilance" ("S" sounds, concentrated mostly in the upper midrange and treble). In this situation, the limiter would ideally limit the signal only when high frequency "S" sounds occur. This is possible by inserting an equalizer into the side chain jack.
This application requires the special stereo-to-dual-mono cord men- tioned above and an equalizer, such as the Alesis MEQ 230.
1.Plug the cord's stereo plug into the 3630's side chain jack.
2.Plug the stereo cord's ring plug into the EQ's input.
3.Plug the stereo cord's tip plug into the EQ's output.
4.Increase the EQ gain in those bands whose frequencies should trigger limiting of the signal. For de-essing applications, try equalizer frequencies in the range of 2 kHz to 10 kHz. Setup for de-essing is quite easy. With a graphic equalizer, select a frequency (2K for example), and set up an excessive boost (as much as 12dB). If the chosen frequency is correct, the excessive gain at that frequency will trigger the compressor when overly sibilant passages occur. If you are successful, try adjacent frequencies one at a time to see which frequency gives the best results. With a parametric EQ, create an excessive boost in the 2kHz - 10kHz band, and sweep the frequency control until best results are obtained. Thus, the high frequency "S" sounds trigger program limiting more readily than the non-"S" sounds.
5.Adjust the Threshold, Ratio, Attack, Release, etc. for the desired de- gree of high-frequency limiting. In de-essing applications, it is your goal to set the attack and release times as fast as possible, so that the sibilant peaks are eliminated without any audible change in the program material.
Frequency Dependent Limiting (Stereo De-essing). The EQ inserted into the 3630's sidechain insert allows excessive sibilance to be limited without affecting the rest of the program content
EQ inserted into 3630's sidechain
