Homemade low-power electronic three-way active speaker

Single channel power amplifier schematic. In this circuit, IC2 and 1C4 are composed of four resistor-capacitor components respectively. The two audio channels 6 of high and low pass of the second-order active filter. Ic3 is connected as an inverter, and is obtained
by sampling simultaneously from the output terminals of IC2, IC3 and IC4.
After the one-time audio voltage signal is mixed and amplified by the low-noise, high-value triode 90 1 4, the emitter outputs a mid-range audio signal mother with a phase opposite to the input
signal . The crossover frequencies are set
to 7. SkHz and 1kHz respectively. The proportion of the unit amplifiers corresponding to the high, medium and low channels in the total audio output power
is approximately equal to 25%; 25P6; 50%, so a special one is chosen. Only high-quality low-power bi-amp integrated circuit IC5 TDA2822 with an upper limit frequency of 120kHz
is used for high and mid-frequency amplification respectively. A TDA2822 bi-amplifier 1C is used for low-frequency unit amplification
, and 6 is connected to BTI. The output method is independently borne. In this way, when the entire power amplifier circuit uses a 12V DC regulated power supply and
the impedance of the three-unit speakers is 8n, the total rated output power of a single channel can reach up to