The audio system comprises a circuit (12) for processing an audio signal, which circuit (12) comprises an input (20) for receiving the audio signal and an output (26) for supplying an output signal. The circuit (12) further includes a harmonics generator (22) coupled to the input (20) for generating harmonics of the audio signal and adding means (24) coupled to the input (20) as well as to the harmonics generator (22) for supplying a sum of the audio signal and the generated harmonics to the output (26). The harmonics generator (22) is embodied so as to limit the amplitude of the generated harmonics.