Xaoc Devices Katowice is a stereo variable band isolator that allows you to control a selected frequency range.With band-by-band stereo and SUM outputs, Katowice is also useful as a crossover network, parametric EQ, DJ-style kill filter, or for band-specific applications such as multi-band compressors and stereo enhancements.
HOW TO USE
Katowice divides the stereo input signal into three bands: Low, Mid and High. The center frequency and bandwidth of the Mid band are defined by the knob and input CV, while Low and High are automatically adjusted so that the sum of the three bands is a complete signal. All three bands pass through a high quality VCA, and the stereo output for each band can be used for further processing in the external module.The SUM output also provides a 3-band mixdown.
The division of the signal into individual frequency bands is performed by a special VC crossover filter.These are designed so that the sum of all three bands reconstructs the original signal without spectral gaps, without attenuation. The frequency response of the three bands is non-resonant and the passband is flat.All of these exceed the cutoff frequency and provide a slope of 3 dB / Oct.
The MID FREQ controls (knobs and CVs) define the geometric center of the Mid band (the center point of the exponential frequency scale).For example, when MID FREQ is set to 2kHz and MID WIDTH is 2 octaves, the Mid band extends from 1kHz to 4kHz (measured at the -6dB split point).The knob also acts as an offset when using the CV input.In addition, there are comprehensive restrictions on frequency division, and settings below 30Hz or settings above 20kHz are not possible.
Katowice provides independent amplitude control for each of the three bands.The slider in each band can attenuate the signal to about -3dB, and this attenuation can also be performed by inputting a negative CV to the corresponding jack.The response of the built-in VCA is exponential, and it becomes unity gain at a voltage of 100V.Moreover, in order to prevent hard clipping, each VCA channel is equipped with a soft saturation circuit which rounds the peak of the signal near 8Vpp. Katowice is factory calibrated to limit the maximum gain to 18dB, but you can also adjust the gain range (including the limit) up to ± 0dB with the trimmer on the back of the module.In this case, please note that the dB scale of the panel is created for the set contents.
Like other analog or digital filters on the market, Katowice introduces a phase shift on the signal.In general, the higher the filter order (the sharper the amplitude response), the more phase shifts will be added and the slighter delay will occur. In Katowice, this delay varies from 0 to 4 milliseconds depending on the frequency.It also adds some fixed phase shifts introduced by AC coupling capacitors.This mainly affects infrasound.
Normally, phase shift (delay) is inaudible unless the processed signal and the original sound are mixed.However, this delay can also be affected by modulating the corner frequency of the filter (modulation of the MID FREQ or MID WIDTH parameters).Side effects are similar to the Doppler effect, where the pitch of the signal changes slightly.Similar to a modulated all-filtering network, this effect can be used creatively to give the sound more animation.