Method for designing a modal equalizer for a low frequency audible range especially for modes positioned very close.

摘要

Method for forming a modal equalizer (5) for audible low frequency range, in particular for frequencies below 200 Hz for a space (1) predetermined and location (2) therein, comprising the steps of: - determining the modes to be equalized at least by center frequency and decay rate of each mode, - creating a description discrete the determined modes, and - determining equalizer coefficients filter based on description discrete the determined modes, and - forming the equalizer (5) by a digital filter by defining the filter coefficients based on the properties of the modes, wherein said method is characterized by the steps of - forming a function mode detection (G (omega)), - defining the angular frequency omega p of the highest peak of the function (G (omega)), - performing an autoregressive analysis predefined order on the version d and minimum phase target response for solving the poles of the mode representing the angular frequency of the highest peak, - selecting the closest point eg omega p of the unit circle pole, to represent with its complex conjugate the most prominent mode, - determining the decay time of said mode and if it is above a predetermined level, designing a filter modal correction for this mode and applying said filter modal correction to the response to be equalized, and - repeating this procedure until no damping time exceeds the predetermined level and - forming the equalizer by combining all the modal correction filters so obtained into a modal equalization filter cascade.