Visteon Global Technolgoies, Inc.

Robert Kelly Cadena

John Elliott Whitecar

J William Whikehart

Gregory Roger Hamel

Andrew Cyril Krochmal

Kai Kwang Lau

A signal processing system and methods for controlling a bandwidth of the signal processing system are disclosed. One method includes the steps of detecting a presence of an adjacent signal on at one adjacent channel relative to a desired channel, detecting a modulation characteristic of the desired channel, measuring a signal strength on the at least one adjacent channel, measuring a signal strength on the desired channel, and adjusting a bandwidth filter applied to the desired channel in response to the measurements and detection steps.

Automatic bandwidth control with high-deviation detection

The presence or absence of a speaker connected to an output terminal of an audio system is determined based on the electro-generator properties of the speaker. The audio system includes an output amplifier coupled to the output terminal. The method includes driving the output amplifier with a predetermined drive signal sufficient to produce a predetermined speaker excursion if a speaker is connected to the output terminal. The output amplifier is then isolated from the output terminal. A signal at the output terminal is sensed after the output amplifier is isolated. The sensed signal is compared with a predetermined reference for determining whether a speaker back-EMF is present. A speaker detection signal is generated indicating absence of a speaker if the back-EMF is not present.

Audio loudspeaker detection using back-EMF sensing

An audio system limits gain in individual audio channels having a shared clip detect signal from a multi-channel power amplifier such that only channels likely to be exceeding the distortion threshold are gain limited. In addition, any arbitrary channels may be grouped together for common gain limiting. The invention monitors the power level of each audio channel, compares the power level to a power threshold that indicates whether a high power condition with the potential to cause excess distortion exists or not, and makes a decision whether to activate each channel's gain limiter based on whether the corresponding clip detect signal is active and the high power condition exists simultaneously for that channel.

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Dearborn, MI, United States of America

Robert Kelly Cadena