2-way active crossover network

Rohit Balkishan Dubla

Description:

The schematic shows a 12dB/oct 2-way active crossover with LR2 alignment. U1 forms the input stage providing a 6dB gain as well as the low impedance drive required by the filters. U2 and U3 form the low-pass and high-pass sections respectively of the crossover. U4 inverts the high-pass filter's output to correct for phase inversion between the filter sections - this is true for all 12dB/oct (i.e., 2nd order) filters sharing a common crossover point. With the resistor/capacitor values shown, the crossover frequency is about 3.4kHz and the filters are 6dB down at the crossover point. The summed frequency response of the crossover is flat and hence the LR2 alignment is considered a better choice for audio over the Butterworth alignment.