LinPlug Spectral - Manual (Page 20)

Note: If an Oscillator which runs in Spread mode (multiple voices) is
chosen, still only one of its voices is used for cross-modulation.
Important: Due to the internal structure of Spectral the harmonics created
through cross-modulation cannot be filtered by the folowing filter. More on
this in the Filter section, when describing the Subsequent Filter (on page
23).
The Gain control finally allows to adjust the volume of the Oscillator before
its fed into its following filter. More info about volume in the Volume info box
following next. This parameter is also available in the Mod Matrix (Osc /
Gain).