Equalizing a multi-input multi-output (MIMO) transfer function is a common task in audio and acoustic signal processing, a process called multichannel inversion or deconvolution. For the MIMO equalization, it has been shown that by taking advantage of fixed poles the design of an IIR equalizer is equally simple when compared to the commonly used FIR equalizer. In many applications parallel filters can be used instead of FIR filters without major modifications to the methods and algorithms, resulting in higher flexibility in frequency resolution. The fixed-pole design of parallel filters is generalized to the multichannel case, and it is shown that the filter parameters can be estimated by the least-squares equations similar to the common FIR equalizers with the added flexibility and modeling efficiency of IIR filters. The method is illustrated with a MIMO crosstalk canceller for a common-enclosure loudspeaker array and results in a significantly better crosstalk cancellation compared to a least-squares FIR MIMO design of comparable computational complexity. Similar savings are foreseen in other acoustic MIMO applications that may benefit from the nonuniform frequency resolution achievable with IIR filters.
Click to purchase paper as a non-member or login as an AES member. If your company or school subscribes to the E-Library then switch to the institutional version. If you are not an AES member and would like to subscribe to the E-Library then Join the AES!
This paper costs $33 for non-members and is free for AES members and E-Library subscribers.