Impedance compensation circuit

If you feel that the periodic attenuator is not very convenient to use, we can divide the attenuation into smaller gears and then
use a switch to switch. For example, if the total attenuation is 6dB, it can be divided into three gears, each gear is 2dB. Calculate
the component parameters of each gear, connect the lines, and use switches to switch gears to meet the actual listening needs.
    The voice coil of the speaker is an inductive component, and its impedance changes with the change of frequency. The higher the frequency,
the higher the impedance of the speaker. The correct design of the crossover requires that the impedance of the speaker is constant, so the change of the speaker impedance will Affects the frequency dividing characteristics of
the frequency divider .
    When the impedance of a speaker connected to a crossover network changes, the filter turning frequency of the crossover network will
change greatly, causing confusion in the crossover characteristics, confusing phase characteristics, and making the frequency response of the speaker system uneven. ,
the overall performance of the system is affected, so it is necessary to perform impedance correction on the phenomenon that the speaker impedance changes with frequency. We generally compensate
    for the increase in speaker impedance . The circuit is shown in the figure.