Page "Audio crossover" Paragraph 42

In this topology, the individual filters are connected in series, and a driver or driver combination is connected in parallel with each filter.

To understand the signal path in this type of crossover, refer to the " Series Crossover " figure, and consider a high frequency signal that, during a certain moment, has a positive voltage on the upper Input terminal compared to the lower Input terminal.

The low pass filter ( LPF ) presents a high impedance to the signal, and the tweeter presents a low impedance ; so the signal passes through the tweeter.

The signal continues to the connection point between the woofer and the high pass filter ( HPF ).

There, the HPF presents a low impedance to the signal, so the signal passes through the HPF, and appears at the lower Input terminal.

A low frequency signal with a similar instantaneous voltage characteristic first passes through the LPF, then the woofer, and appears at the lower Input terminal.