The Sonoris Equalizer is a parametric equalizer in the SAWStudio native format. The plugin is suitable for mixing and mastering and features 7 bands, including lowpass, highpass, peaking and shelving filters.
The plugin has a large graphical display that shows exactly what you get. The Sonoris Equalizer has a HQ switch that enables an upsampling mode.
In this mode, the Equalizer has an even more acurate response, especially at the higher frequencies. The aim was to create an equalizer with filters that match the response of their analog counterparts over the entire frequency range.
Most digital suffer from the so called pre-warping effect. This is an unwanted effect that occurs when translating an analog transfer function (the S-domain) mathematicaly to the digital domain (= z-domain).
This is mostly done by a process called bi-linear transformation and as a side-effect this process causes the gain to be zero dB at Nyquist ALLWAYS, independant of how you set the controls.
This alone is not that bad, BUT the filters start behaving weird far below the Nyquist frequency and the result is a distorted frequency response.
Switching peaking/shelving filter on and off is done with Soft Engage technology, that guarantee no pops and crackles. This technology is also used when adjusting the other controls of this bands.