If you want to make your laptop/notebook sound louder, you can add simple Audio Amplifier like this project. Built based on IC LA 4440, the amplifier only need few passive components. This dual channel audio power amplifier has low distortion over a wide range of low to high frequencies with good channel separation. Its built-in dual channels enable it for stereo and bridge amplifier applications.
LA4440 gives 6 watts per channel in dual mode and 19 watt output when used in bridge mode. It has ripple rejection of 46 dB. To use this amplifier, you need to connect pins 2, 6 and ground of IC LA 4440 to audio port output of laptop. Two 6-watt speakers are required to get audio effect for this amplifier. The circuit needs 12V regulated power supply to works and don’t forget to use a proper heat-sink for LA4440.