Patent Document ID: 7742607
Application ID: 10293600
Patent Flag: 1

Claim One:
1. A method for designing a modal equalizer for low frequency sound reproduction in a predetermined space within a room and location therein, wherein the low frequency sound is within a range below 200 Hz, and wherein the room has a plurality of room modes, said method comprising: determining the room modes, by determining corresponding rates of decay across the low frequency range; selecting modes to be equalized based on the corresponding determined rates of decay; determining center frequencies for each said selected modes; and defining coefficients of an infinite impulse response (IIR) modal filter based upon the corresponding rates of decay for each of the selected room modes, characterized by for each selected mode, designing a modal correction filter provided as a relation between an estimate of pole location and a desired pole location, where at least the estimated pole locations are determined from respective said rates of decay, and forming the IIR modal filter as a cascade of the modal correction filters.