Resonance is also called ‘Q’ or Emphasis in synthesizers, because it emphasizes the cutoff point of the filter. Resonance can often increase the loudness of the Filter, so its a good idea to use this control along with the Filter Gain, so that audio clipping does not occur.
TIP: Omnisphere’s UVI1 filter can self-oscillate. To achieve this effect, set the Resonance to maximum, and the filter can then be ‘tuned’ by the cutoff control.
NOTE: Omnisphere’s resonant filters are unusual. Turn up the Resonance and Variant while holding a note and turn the Filter Cutoff higher. The pitch goes down with the filter when the Cutoff goes up. That means the Key Tracking must be inverted to get the pitch to go up as you go up the keyboard.