LinPlug Spectral - Manual (Page 73)

Master EQ
All Audio finally gets through the Master EQ, if its switched On. Its the last
audio processing before Audio is routed to the host (your DAW).
The Master EQ has the same controls as the Parametric EQ described on
page 66, plus a Low-Cut and a High-Cut Filter, suited for removing
frequencies at the lower or upper end of the frequency range.
Both Cut filters have a Freq (Frequency) parameter to adjust the operation
frequency, the range for the Lo-Cut is DC (0 Hz) up to 640 Hz and for the
Hi-Cut 640 Hz to 22 kHz. The Lo Cut more or less reduces frequencies
below its operating frequency, depending on the Stages parameter
described next. For the Hi-Cut all frequencies above the operation
frequency are reduced.
Both also have a Stages parameter which controls how many 6dB Stages
are used, the range is 1 to 8 so the roll-off of each shelf-filter can be
adjusted between 6 dB/Octave up to 48 dB/Octave.