This circuit using IC LA4445 , this is stereo amplifier with power output 2 X 18 Watt, with this circuit you can use to car amplifier or to other elctronics device. Speaker use woofer with impedance 4 Ohm with power up to 20 Watt. Minimum voltagte require 10 Volt and maximum voltage 18 volt.
see schematic below :
If you can't operate the circuit , please check IC , and then voltage in. If voltage is good check the component are. If components are working . Please check speakers.