Adjust low frequencies using the Boost and Atten knobs and the Low Frequency switch, located at the left side of the unit. All low-frequency equalization is a gentle shelving type, 6 dB per octave.Boost mid and high frequencies using the Bandwidth and Boost knobs and the High Frequency switch.Cut high frequencies using the Atten knob and the Atten Sel switch located at the right side of the plug-in.