LinPlug Spectral - Manual (Page 66)

EQ (Parametric)
The Spectral’s Parametric EQ (Equalizer) effect contains 2 independent
parametric equalizer stages in series. It is very similar to the Master EQ,
but without the Cut-Filters.
The Freq (Frequency) control sets the frequency at which the EQ operates.
A range of 20 Hz to 11.000 Hz is available.
The Gain control sets the amount of gain that is applied to the selected
frequency. Note that the gain can be positive or negative. A positive gain
corresponds to boosting the signal while a negative gain corresponds to
cutting the signal. A range of +-18 dB is available.
The Q (Quality) controls set the bandwidth of the filter. A large value means
that a wider bandwidth is affected while a smaller values means only a
narrow band is affected.