The invention relates to an audio system for generating an audio signal. More specifically the invention relates to an audio system, especially an audio alarm system, for generating an audio signal comprising means for generating a component of the audio signal at a base frequency and means for generating further components of the audio signal at other frequencies than the base frequency, whereby the base and the other frequencies are separated from each other by separating frequency bands in order to enhance the loudness of the audio signal. The invention furthermore relates to a method for generating an audio signal, a computer program and an audio signal.