Application of LM3886 in home theater 03

 (3) Subwoofer active speaker.
    Figure 10-13 is a home subwoofer active speaker circuit. In the figure, the Linkwitz active compensator accurately controls
the center frequency F and Q value of the compensation peak, and can make a closed box with a natural turning frequency of about 50Hz. The power circuit
is shown in Figure 10-14, and the frequency response curve is shown in Figure 10- As shown in 15, it extends downward gently, and the low-end 3dB
point reaches 25Hz. Curve a in Figure 1 0·1 5 is the natural frequency response, and b is the compensation curve.
c is the system frequency response. The turning frequency of the low-pass filter is continuously adjustable from 80Hz to 200Hz
, so that the active subwoofer can match the reader's two-channel speakers with different lower frequency limits. The
protruding speaker is Yindi YD310-43, with a basin diameter of 310mm and a magnet
diameter of 158mm. ． The resonance frequency is 25Hz, Q=0.35. The continuous power is 50w. The
sensitivity is as high as 95dBo. Compared with the Hivi S8 unit with a sensitivity of 88dB,
the sensitivity difference between the two is 7dB. If the box is closed at the same time, the output sound pressure of Yindi YD310-43 when sow is input is equivalent to
the input of the Hivi S8 unit ≥ Output at 200W. You can also use Nanjing YD310-8XA to replace the silver flute. The cabinet should not use an inverter box with poor transient performance and low sensitivity
, but should use the simplest closed box. The cabinet should be strong and airtight, and should be filled with fiberglass cotton or acrylic cotton for saliva protection.