Control of a loudspeaker output
AssigneeNXP B.V.
InventorTemujin Gautama
Life of this patent
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Abstract
A method of controlling a loudspeaker output comprises deriving an admittance function over time from the voice coil voltage and current. In combination with a delta function, the force factor of the loudspeaker and the blocked electrical impedance, the input-voltage-to-excursion transfer function over time is obtained. This is used to control audio processing for the loudspeaker thereby to implement loudspeaker protection and/or acoustic signal processing; The invention provides a modelling and control approach which is not based on a parametric model. As a consequence, it does not require prior knowledge regarding the enclosure (e.g. closed or vented box) and can cope with complex designs of the enclosure.
Claims11
A method of controlling a loudspeaker output, comprising:
- measuring a voice coil voltage and a voice coil current over time,
- deriving an admittance function over time;
- combining the admittance function over time with a delta function, a force factor of a loudspeaker and a blocked electrical impedance;
- and
- calculating an input-voltage-to-excursion transfer function over time from the admittance function, the blocked electrical impedance and the force factor;
- and
- using the input-voltage-to-excursion transfer function over time to control audio processing for the loudspeaker thereby to implement at least one of loudspeaker protection and acoustic signal processing.
A loudspeaker control system, comprising:
- a loudspeaker;
- a sensor for measuring a voice coil voltage and a voice coil current;
- and
- a processor,
- wherein the processor is adapted to:
- measure a voice coil voltage and a voice coil current over time and derive an admittance function over time;
- combine the admittance function over time with a delta function, a force factor of the loudspeaker and a blocked electrical impedance;
- and
- calculate an input-voltage-to-excursion transfer function over time from the admittance function, the blocked electrical impedance and the force factor;
- and
- use the input-voltage-to-excursion transfer function over time to control audio processing for the loudspeaker thereby to implement at least one of loudspeaker protection and acoustic signal processing.
Dependencies are inferred from the claim text.