MZ1812 application circuit

M21812 has good tracking ability below 300H, but
when the turning frequency _fc of LPF1 and LPF2 is too high, the divided signal of fi will still be in the mid-frequency range, causing the signal in the mid-bass band (around 100Hz) to be too high. Strong and makes the sound muddy; if fc is too low, the speaker
may not be able to play. Generally, c should be set at 200Hz. This circuit works at about 160Hz. The component values ​​in brackets are suitable for large speakers. c is 78 HZ .     The time constant of the 16-pin external RC circuit of M21812 affects the distortion and tracking characteristics of the circuit. When Rr8 is 33kfl, the recommended value of C18 is o,l~l庐. The size of C17 connected to pin 17 will also affect the above parameters.     The working voltage of M21812 is 13 ~ 18V, the signal-to-noise ratio is 93dB, the total harmonic distortion is <1.3%, and the quiescent current is about 15mAo.     This circuit has a very outstanding subwoofer effect and is relatively flexible in application. It can use a dedicated subwoofer or directly Connect to the system to broaden the low-frequency response of the main speakers .