Sonalksis CQ1

The 'frequency selective' processing employed by the CQ1 is far more sophisticated than standard 'frequency conscious' multi-band compression.

The CQ1 greatly extends the possibilities of dynamics processors with the ability to refine specific frequency compression or expansion with unparalleled accuracy. Although it uses the same dynamic-EQ principle as the DQ1, the CQ1 is designed primarily to provide gentle or aggressive shaping of the signal dynamics in explicit frequency bands, rather than the subtle frequency sculpting of the DQ1.
The Sonalksis CQ1 is a multi-band frequency-selective dynamics processor, allowing independent compression or expansion of four freely adjustable filter bands. Unlike typical multi-band compressors that are designed primarily to master composite program material, the CQ1 uses the principle of 'dynamic equalisation' and is therefore suitable for a much broader range of applications.
In addition to general program compression/expansion, the CQ1 will find uses in applications that may otherwise present difficulties for less flexible processors, including Multi-source separation, High/Low frequency enhancement, Transient enhancement and De-essing or Pop/Squeak reduction.
For example if you want to reduce annoying guitar fret squeaks, tune the CQ1 side-chain filter to the squeak frequency, and centre a hi-Q notch with 'above threshold' compression; this will compress the squeak without removing any other unrelated frequencies. Or when you want to emphasise the percussive nature of an instrument without emphasising the entire mix, use the CQ1 tuned only to the fundamental instrument range, with 'above threshold' expansion, and you will achieve a transient enhancement effect.