Using the Sidechain Input on the MClass Compressor

Ducking effects are when one sound causes another sound to temporarily lower in volume, or duck, when and only when that first sound is played. You can either duck out the master volume of another sound or you can duck out the volume of a range of frequencies using an EQ box.

When creating music that depends on a kick drum and a bass line for the groove, ducking effects are just about required. In Reason Version 2.5, sidechain-ducking effects could be imitated, but something about the procedure didn’t really sound right, especially because you couldn’t do it in stereo. With the sidechain inputs on the MClass Compressor in Version 3.0, however, ducking effects are now possible in full stereo, as shown in Figure 1.28. Sidechaining is also how you would do a voice over effect.