Method and arrangement for automatically limiting distortion in audio devices
AssigneeVolkswagen Aktiengesellschaft
InventorDetlev Beyer
Life of this patent
Estimating the term…
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.
Claims8
A method for automatically limiting distortion in an audio device utilizing a distortion detector for determining a harmonic distortion factor and supplying a corresponding signal to a gain regulation input of the audio device, comprising:
- determining in the distortion detector a plurality of harmonic distortion factors, each corresponding to one of a plurality of selected audio frequencies of an output signal of the audio device in a frequency-dependent manner, said plurality of harmonic distortion factors comprising the ratios of the root mean square values of the harmonics and the fundamentals in the output signal;
- and
- generating a control signal that reduces the overall gain of the audio device when at least one of the harmonic distortion factors exceeds the corresponding frequency-dependent, adjustable harmonic distortion factor threshold value.
A method for automatically limiting distortion in an audio device utilizing a distortion detector for determining a harmonic distortion factor and supplying a corresponding signal to a gain regulation input of the audio device, comprising:
- determining in the distortion detector a plurality of harmonic distortion factors, each corresponding to one of a plurality of selected audio frequencies of an output signal of the audio device in a frequency-dependent manner, said plurality of harmonic distortion factors comprising the ratios of the root mean square values of the harmonics and the fundamentals in the output signal;
- and
- adjusting the overall gain of the audio device until at least one of the plurality of harmonic distortion factors reaches the corresponding frequency-dependent threshold value.
A circuit arrangement for automatically limiting distortion in an audio device comprising:
- an audio device;
- and
- a frequency selective distortion detector which receives an output of the audio device and determines a plurality of harmonic distortion factors, each corresponding to one of a plurality of selected audio frequencies, said plurality of harmonic distortion factors comprising the ratios of the root mean square values of the harmonics and the fundamentals at the output;
- and
- a plurality of comparators responsive to a plurality of determined harmonic distortion factors in corresponding individual audio frequency ranges having independent threshold values for a corresponding harmonic distortion factor, arranged in a feedback path from the output of the audio device which supplies an overall gain regulation signal to a gain control input of the audio device.
Dependencies are inferred from the claim text.