Cirrus Logic Inc.

Stefan Williams

Roberto Napoli

Jason William Lawrence

Jie Su

Firas Azrai

Rong Hu

Roger David Serwy

This application describes methods and apparatus for loudspeaker protection. A loudspeaker protection system () is described having a first frequency band-splitter () for splitting an input audio signal (Vin) into a plurality of audio signals (v, v. . . ,vn) in different respective frequency bands (&#x3c9;. . . &#x3c9;&#x3b7;). A first gain block () is configured to apply a respective frequency band gain (gt, gt. . . ,gt) to each of the audio signals in the different respective frequency bands and a gain controller () is provided for controlling the respective band gains. A thermal controller () determines, for each of a plurality of the different respective frequency bands, a power dissipation for the loudspeaker in that frequency band and also determines a respective thermal gain setting based on the determined power dissipation for that frequency band. The gain controller is configured to control the respective frequency band gains based on the thermal gain settings.

Loudspeaker protection

This application describes methods and apparatus for loudspeaker protection. A loudspeaker protection system () is described having a first frequency band-splitter () for splitting an input audio signal (Vin) into a plurality of audio signals (v, v. . . , vn) in different respective frequency bands (&#x3c9;. . . , &#x3c9;n). A first gain block () is configured to apply a respective frequency band gain (g, g. . . , g) to each of the audio signals in the different respective frequency bands and a gain controller () is provided for controlling the respective band gains. A displacement modeller () determines a plurality of displacement signals (x, x. . . , xn) based on the input audio signal (Vin) and a displacement model () where each displacement signal corresponds to a modelled cone displacement for the loudspeaker for one of said different respective frequency bands. The gain controller () is configured to control the respective frequency band gains based on the plurality of displacement signals.

A method of thermal protection of a voice coil of a loudspeaker comprises: determining an estimate of a temperature of the voice coil, determining an estimate of a rate of change of the temperature of the voice coil, determining an estimate of power dissipation in the voice coil, and generating a gain control signal for modulating a gain applied to an input signal in a signal path between an input terminal and the loudspeaker. The gain control signal is generated as a function of all of the estimate of the temperature of the voice coil, the estimate of the rate of change of the temperature of the voice coil, and the estimate of the power dissipation in the voice coil.

Growing community of inventors

London, United Kingdom

Stefan Williams