Control of a loudspeaker output
AssigneeNXP B.V.
InventorTemujin Gautama
Life of this patent
Estimating the term…
Abstract
A method of modeling the frequency-dependent input-voltage-to-excursion transfer function of a loudspeaker, comprises, for a plurality of measurement frequencies, measuring a voltage and current and deriving an impedance at the measurement frequency. A frequency-dependent impedance function is derived. By additionally using the blocked electrical impedance and a force factor for the loudspeaker, a frequency-dependent input-voltage-to-excursion transfer function can be calculated. The invention provides a modeling approach which is not based on a parametric model, but computes the transfer functions for a set of frequencies separately. 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.
Claims14
A method of controlling a loudspeaker output, comprising:
- modelling a frequency-dependent input-voltage-to-excursion transfer function of a loudspeaker, by:
- for a plurality of measurement frequencies, measuring a voltage and a current and deriving an impedance at the measurement frequency, and from the plurality of impedance values deriving a frequency-dependent impedance function;
- one of estimating, measuring and obtaining the blocked electrical impedance and a force factor for the loudspeaker;
- calculating the frequency-dependent input-voltage-to-excursion transfer function from the impedance function, blocked electrical impedance and force factor;
- and
- using the frequency-dependent input-voltage-to-excursion transfer function to control audio processing for the loudspeaker.
A loudspeaker control system, comprising:
- a loudspeaker;
- a sensor for measuring a voltage and a current for a plurality of measurement frequencies;
- and
- a processor,
- wherein the processor is configure to:
- derive an impedance at each measurement frequency, and from the plurality of impedance values derive a frequency-dependent impedance function;
- calculate a frequency-dependent input-voltage-to-excursion transfer function from the impedance function and from a blocked electrical impedance and a force factor for the loudspeaker;
- and
- use the frequency-dependent input-voltage-to-excursion transfer function to control audio processing for the loudspeaker.
A non-transitory computer-readable storage medium having a computer program comprising computer program code configured to perform an operation, the operation includes:
- modelling a frequency-dependent input-voltage-to-excursion transfer function of a loudspeaker, by:
- for a plurality of measurement frequencies, measuring a voltage and a current and deriving an impedance at the measurement frequency, and from the plurality of impedance values deriving a frequency-dependent impedance function;
- one of estimating, measuring and obtaining the blocked electrical impedance and a force factor for the loudspeaker;
- calculating the frequency-dependent input-voltage-to-excursion transfer function from the impedance function, blocked electrical impedance and force factor;
- and
- using the frequency-dependent input-voltage-to-excursion transfer function to control audio processing for the loudspeaker.
Dependencies are inferred from the claim text.