Patent ID: 7286674
Filing Date: 2007-10-23
Classification: H03G,H04R

Abstract:
1. A method for designing a modal equalizer ( 5 ) for a low frequency audible range, including frequencies below 200 Hz for a location in a listening room therein, in which method modes to be equalized are determined at least by center frequency and decay rate of each mode in said location, creating a discrete-time description of the determined modes, and determining equalizer filter coefficients on the basis of the discrete-time description of the determined modes, and forming the equalizer ( forming a mode detection function (G(Ω)), defining highest peak angular frequency Ω making AR analysis of predefined order for solving the poles of the mode representing the highest peak angular frequency, wherein AR analysis is auto-regressive analysis, selecting the pole closest to point e determining the decay time of the mode and if is over a predetermined level, designing a modal correction filter for this mode, and repeating this procedure until no decay time exceeds over the predetermined level and each individual filter obtained in previous stages of the method is combined to a cascaded modal equalization filter.