The present invention is related to an apparatus and a method for controlling operations of low sound output in an audio system. Embodiments of an apparatus and a method for controlling an operation of an audio woofer in a machine provided with an audio system such as a portable computer can operate using at least one or more information of an audio data type, an audio signal, an audio channel number and a power source. Therefore, it is possible to accurately select and listen to an audio of a high-pass component only by stopping operations of a low-pass component for an audio as reproduced. In addition, embodiments of the present invention can extend a time for using a battery by controlling operations of a woofer, when using the battery power.