C1 Parametric Compander is Waves' primary compressor. It is available in four versions — C1 Compressor, C1 Gate, C1 Compressor/Gate, and C1 Compressor/Sidechain — which variously offer optional gating, filtering, and sidechaining. The full-blown version, C1 Compressor/Gate, includes all three. The Gate/Expander section is typically used to manage low-level signals, such as noise. The sidechain lets one signal control the level of another, which is useful for ducking. When you don't need to get fancy, use the C1 Compressor; it offers no gate, no ducking, no filter, and no wasted CPU cycles. Gold Native also includes a dedicated DeEsser. It doesn't do anything that you can't do in C1, but it is CPU-efficient and easier to use.
The filter section, one of C1's most powerful features, uses a lowpass, highpass, bandpass, or band-reject filter to define active and passive regions (see Fig. 2). The filter, which you can apply to the sidechain and the main signal, has a variety of applications, including classic compression, expansion, gating, dehissing, de-essing, noise reduction, dynamic equalization, and so forth. Setups are supplied for each task, and the documentation has more than you ever wanted to know about parametric companding.
The other Gold Native compressor, Renaissance Compressor, emulates vintage hardware compressors. It is optimized for warmth of sound and simplicity of operation. Optional automatic release control (ARC) can be applied with Opto or Electro response, which increases or decreases, respectively, the release time near the threshold. An optional warmth enhancer adds low-frequency harmonics at deeper compression levels. The signal path ends with a hard limiter similar to L1 that is applied after compression.
The newest and most sophisticated offering in the compression category is the C4 Multiband Parametric Processor. (For a review of C4, see the February 2001 issue.) The incredibly powerful hybrid applies separate compression to four parametric-equalizer bands. You could also think of the plug-in as a 4-band dynamic equalizer, because separate bands of compression change the EQ curve.
C4's compressors replace the standard threshold control with a Range control. The Gain setting applies when no compression is occurring, and the Range setting indicates the gain change at maximum compression. That flexible arrangement lets you apply compression at low thresholds without getting extreme gain changes at high signal levels, because the Range setting limits the maximum gain change.
C4 works well as a mastering tool when frequency bands call for different sorts of compression and EQ. It also offers greater flexibility in noise reduction because you can apply varying amounts of reduction to different parts of the frequency spectrum. Finally, C4 makes an excellent decompressor, letting you selectively expand frequency bands in an overly compressed mix. The 19 factory Setups illustrate a good cross section of its capabilities.
