The second band is the parametric midrange. This band has two bandwidth values, 1/4 octave and 2 octaves. These control the width of the curve.

The horizontal center line of the graph is zero. As you move the curve below the zero line, the corresponding frequencies are deemphasized. Above the zero line, the corresponding frequencies are emphasized. The parametric midrange allows a smooth transition from deemphasized frequencies to emphasized frequencies. See Using the Audio EQ Tool.