Patent ID: 8363853

Claim:
A method for equalizing audio signals provided to speakers, the method comprising: measuring loudspeaker-room acoustics to obtain time domain room response data; processing the time domain room response data with a Linear Predictive Coding (LPC) model to obtain smoothed time domain room response data; performing an FFT on the smoothed time domain room response data to obtain smoothed frequency domain room response data; computing center frequency F c , a gain G, a bandwidth BW, and a term Q factor for a plurality of parametric Infinite-duration Impulse Response (IIR) filters from the smoothed frequency domain room response data includes a method for determining a number of peaks num_peaks comprising: computing a frequency response HH2 from a linear predication coefficient q wherein elements in the frequency response HH2 correspond to an array of frequencies FF; given an interested frequency range between LO_FREQ and HI_FREQ in Hz, and a low bin bin_lo and a high bin, bin_hi, updating the array of frequencies FF such that the elements of the updated the array of frequencies FF are the frequencies in the interested frequency range; computing HH2_abs, the magnitude of HH2, based on the bin_lo and bin_hi in the interested frequency range; determining peak locations peak_loc and valley_locations valley_loc while ensuring that a first peak occurs before a first valley; saving a number of peak locations as the num_peaks; and determining the center frequency Fc and gain G of each peak based on the peak location peak_loc and the magnitude HH2_abs at the peak location; cascading the plurality of parametric IIR filters to form an equalizing filter; equalizing a signal with the equalization filter to obtain an improved loudspeaker-room response; and providing the equalized signal to a speaker to provide improved sound production.