Patent ID: 7593535
Filing Date: 2009-09-22
Classification: H04R,H04S

Abstract:
1. A method of determining inverse linear and non-linear transfer functions of an audio transducer for precompensating an audio signal for reproduction on the transducer, comprising: a) Synchronized playback and recording of a linear test signal through the audio transducer; b) Extracting a forward linear transfer function for the audio transducer from the linear test signal and recorded version thereof; c) Inverting the forward linear transfer function to provide an estimate of an inverse linear transfer function A( ) for the transducer; d) Mapping the inverse linear transfer function to corresponding coefficients of a linear filter; e) Synchronized playback and recording of a non-linear test signal I through the transducer; f) Applying the linear filter to the recorded non-linear test signal and subtracting the result from the original non-linear test signal to estimate a non-linear distortion of the transducer; g) Extracting a forward non-linear transfer function F( ) from the non-linear distortion; and h) Inverting the forward non-linear transfer function to provide an estimate of an inverse non-linear transfer function RF( ) for the transducer.