The C4 Quad Compressor/Limiter presents matchless feature, performance and ergonomic value. Rounding out Rane's popular series of analog-controlled digital products for live sound applications, the C4 offers four feature-packed channels of compression and limiting in a 2U package. Internal and external side-chain options 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. Adjacent channels link in a master/slave arrangement to ensure accurate tracking of stereo inputs. Intuitive meters show side-chain level relative to Threshold, gain reduction and complete dynamic range at a glance. A de-essing 'preset' in each channel is found by aligning the controls to the triangles, but with far greater control than other de-essers.
The C4 is a member of Rane's analog-controlled digital family of products, including the G4
gate, AC 24 crossover, DEQ 60 and DEQ 60L
graphic equalizers, and the PEQ 55 parametric equalizer.Analog-Controlled Digital
Analog controls (knobs, sliders) allow a performer or sound engineer to make precise adjustments, in real time. Digital signal processing (DSP) provides a degree of accuracy, consistency and flexibility that simply cannot be matched with a traditional analog design.
The C4 combines the best of both worlds by using analog controls and high performance digital processing to achieve an unprecedented feature set. Benefits of this approach:
- Allows the use of advanced compression and dynamic equalization techniques which are difficult or costly to implement in traditional analog designs.
- Improved accuracy and repeatability.
- Exceptional immunity to RF and electromagnetic interference.
- Lower cost per channel.
The C4 uses a relative threshold approach to dynamic EQ to ensure precise, predictable performance. Unlike traditional de-essers, which simply use an EQ boost in the side-chain to increase the compressor's sensitivity to high frequencies, 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 broadband (full-range) sound, and is not affected by changes in absolute level. The result: sizzly sounds are successfully subdued during soft or strident sections. A de-essing 'preset' in each channel is found by aligning the controls to the triangle markers.
A compressor with a simple side-chain EQ boost is not a true de-esser. Gain reduction is directly affected by varying input levels, not the actual ratio of broadband to sibilant material.