Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Equalization of Loudspeaker and Room Responses Using Kautz Filters: Direct Least Squares Design | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2007 Article ID 60949 13 pages doi 2007 60949 Research Article Equalization of Loudspeaker and Room Responses Using Kautz Filters Direct Least Squares Design Matti Karjalainen and Tuomas Paatero Department of Electrical and Communications Engineering Laboratory of Acoustics and Audio Signal Processing Helsinki University of Technology . Box 3000 FI 02015 Finland Received 30 April 2006 Revised 4 July 2006 Accepted 16 July 2006 Recommended by Christof Faller DSP-based correction of loudspeaker and room responses is becoming an important part of improving sound reproduction. Such response equalization EQ is based on using a digital filter in cascade with the reproduction channel to counteract the response errors introduced by loudspeakers and room acoustics. Several FIR and IIR filter design techniques have been proposed for equalization purposes. In this paper we investigate Kautz filters an interesting class of IIR filters from the point of view of direct least squares EQ design. Kautz filters can be seen as generalizations of FIR filters and their frequency-warped counterparts. They provide a flexible means to obtain desired frequency resolution behavior which allows low filter orders even for complex corrections. Kautz filters have also the desirable property to avoid inverting dips in transfer function to sharp and long-ringing resonances in the equalizer. Furthermore the direct least squares design is applicable to nonminimum-phase EQ design and allows using a desired target response. The proposed method is demonstrated by case examples with measured and synthetic loudspeaker and room responses. Copyright 2007 M. Karjalainen and T. Paatero. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. INTRODUCTION .
