The graph in Figure 14-1 depicts one
particular type of equalization known
as a shelving characteristic or shelving
curve. Let's examine the shelving type
EQ created by the bass control. The
graph indicates that the boost or cut
gradually builds below the 1000 Hz
hinge point. With the control set at one
extreme or the other, the circuit
produces 10 dB of boost or cut at
100 Hz, with less and less effect above
that frequency. Below 100 Hz the
amount of boost or cut remains constant,
as shown by the response plot
that has ceased to slope and is again
level. This new boosted or cut level
portion of the curve looks like a shelf,
hence the term shelving.