Sound-field reproduction in-room using optimal control techniques: simulations in the frequency domain.

This paper describes the simulations and results obtained when applying optimal control to progressive sound-field reproduction (mainly for audio applications) over an area using multiple monopole loudspeakers. The model simulates a reproduction system that operates either in free field or in a closed space approaching a typical listening room, and is based on optimal control in the frequency domain. This rather simple approach is chosen for the purpose of physical investigation, especially in terms of sensing microphones and reproduction loudspeakers configurations. Other issues of interest concern the comparison with wave-field synthesis and the control mechanisms. The results suggest that in-room reproduction of sound field using active control can be achieved with a residual normalized squared error significantly lower than open-loop wave-field synthesis in the same situation. Active reproduction techniques have the advantage of automatically compensating for the room's natural dynamics. For the considered cases, the simulations show that optimal control results are not sensitive (in terms of reproduction error) to wall absorption in the reproduction room. A special surrounding configuration of sensors is introduced for a sensor-free listening area in free field.

[1]  A. Berkhout,et al.  Acoustic control by wave field synthesis , 1993 .

[2]  Gary W. Elko,et al.  Effect of loudspeaker position on the robustness of acoustic crosstalk cancellation , 1999, IEEE Signal Processing Letters.

[3]  Hareo Hamada,et al.  The stereo dipole : A virtual source imaging system using two closely spaced loudspeakers , 1998 .

[4]  Hareo Hamada,et al.  SOUND FIELDS FOR THE PRODUCTION OF VIRTUAL ACOUSTIC IMAGES , 1997 .

[5]  Marvin Camras,et al.  Approach to Recreating a Sound Field , 1967 .

[6]  Mark Franklin Davis.  History of Spatial Coding , 2003 .

[7]  Philip A. Nelson,et al.  Optimal source distribution for binaural synthesis over loudspeakers. , 2002 .

[8]  John Mourjopoulos,et al.  Errors in Real-Time Room Acoustics Dereverberation* , 2004 .

[9]  O. Kirkeby,et al.  Reproduction of plane wave sound fields , 1993 .

[10]  Steven J. Elliott,et al.  Practical Implementation of Low-Frequency Equalization Using Adaptive Digital Filters , 1994 .

[11]  Hareo Hamada,et al.  Inverse filter design and equalization zones in multichannel sound reproduction , 1995, IEEE Trans. Speech Audio Process..

[12]  Felipe Orduña-Bustamante,et al.  Multi-Channel Signal Processing Techniques in the Reproduction of Sound , 1992 .

[13]  O. Kirkeby,et al.  Local sound field reproduction using digital signal processing , 1996 .

[14]  Philip A. Nelson,et al.  Multiple-Point Equalization in a Room Using Adaptive Digital Filters , 1989 .

[15]  Hareo Hamada,et al.  Adaptive inverse filters for stereophonic sound reproduction , 1992, IEEE Trans. Signal Process..

[16]  Philip A. Nelson.  Active Control Of Acoustic Fields And The Reproduction Of Sound , 1994 .

[17]  P. Nelson,et al.  ESTIMATION OF ACOUSTIC SOURCE STRENGTH BY INVERSE METHODS: PART I, CONDITIONING OF THE INVERSE PROBLEM , 2000 .