Abstract: An audio system for vehicles, in particular for motor vehicles, comprises a device component (A) permanently fixed to the vehicle, and a mobile component (B) connected to the device component in a mechanically detachable way. The device component further comprises a control unit (1), and the mobile component further comprises a transponder for storing a numerical code. The function of the audio system is interrupted when the mobile component is removed from the device component, and resumed, following an authorization check, when the mobile component (B) is replaced. The authorization check is performed by the control unit which further comprises a comparator unit (2) for comparing the numerical code transmitted by the transponder (T) with a security code previously stored in the device component.

Abstract: A method and arrangement for automatically limiting distortion in audio devices utilizes a distortion detector for determining a harmonic distortion factor and the output of the distortion detector is fed back to a gain regulation input of the audio device. The distortion detector determines the harmonic distortion factor of the output signal of the audio device in a frequency-dependent manner and, when the harmonic distortion factor exceeds a frequency-dependent, adjustable threshold value, the detector generates a control signal that reduces the gain of the audio device.

Abstract: An arrangement for reproducing audio signals includes a pitch control device for increasing or decreasing the amplification of audio signals in one or more defined frequency ranges and a volume control device for increasing and decreasing the amplification of the audio signals in a full effective frequency range of the audio signals wherein the pitch control device reduces the amplification in the defined frequency ranges if the amplification of the audio signals in the full effective frequency range is increased by the volume control device and wherein the pitch control device increases the amplification of the audio signals in the defined frequency ranges if the volume control device decreases the amplification of the audio signals in the full effective frequency range.

Abstract: A method for sound control of audio signals within a defined frequency range in which the gain of the audio signals is varied using a control element and the filter quality factor and/or the mid-frequency of the audio signals are varied simultaneously by the same control element used to control the gain.