Subowoofer audio car amplifier

For the a one amplifier circuit is very suitable for use in applications subwoofer speaker, which allows for higher spending enough bass. Although output was spent not high, but for bass sounds do not undoubtedly. Indeed, the output is only 20W mono amplifier with 8 ohm impedance. With a maximum supply 44Volt DC.

Part list
R1 = 47R
R2 = 100K
R3 = 1R 2W
C1 = 2.2uF
C2 = 220uF
C3 = 100uF
C4 = 47uF
C5 = 68uF
C6 = 100uF
C7 = 1000uF
C8 = 0.1uF
U1 = STK024 , STK031 ,STK035