The C4 from Rane is a four channel compressor/limiter with internal and external side-chain options that offer a fully adjustable parametric EQ for frequency-dependent compression or de-essing. The oversampled brick wall limiter determines the maximum output level and operates independent of the compressor.
The unit uses a relative threshold approach to de-essing to ensure precise, predictable performance. Unlike traditional de-essers, which simply use an EQ boost in the side-chain, the C4 actually determines the amount of sibilance present in the program material and compares it to the overall signal content. The benefit to this approach is that de-essing depends only on the relationship between sibilant sound and the full-range sound and is not affected by changes in absolute level.
Adjacent channels can be linked in a master/slave arrangement to ensure accurate tracking of stereo inputs. Meters show side-chain level relative to threshold, gain reduction and complete dynamic range at a glance. Analog-controlled digital processing allows a performer or sound engineer to make precise adjustments, in real time using analog controls, while digital signal processing provides a degree of accuracy, consistency and flexibility that simply cannot be matched with a traditional analog design.