MULTIPLE POINT LEAST SQUARES EQUALISATION IN A ROOM

Equalization filters designed to minimize the mean square error between a delayed version of the original electrical signal and the equalized response at a point in a room have previously been investigated by several authors. In general such a strategy degrades the response at positions in the room away from the equalization point. A method is presented for designing an equalization filter by adjusting the filter coefficients to minimize the sum of the squares of the errors between the equalized responses at multiple points in the room, and delayed versions of the original electrical signal. Such an equalization filter can give a more uniform frequency response over a greater volume of the enclosure than the single point equalizer above. Computer simulation results are presented of equalizing the frequency responses from a loudspeaker to various typical ear positions, in a "room" with dimensions and acoustical damping typical of a car interior, using the two approaches outlined above. Adaptive filter algorithms, which can automatically adjust the coefficients of a digital equalization filter to achieve this minimization, are also discussed.

• Corporate Authors:

  Southampton University, England

  Institute of Sound and Vibration Research
  Southampton S09 5NH, Hampshire,   England 
• Authors:
  • Elliot, S J
  • Nelson, P A
• Publication Date: 1988-9

Media Info

• Pagination: 25 p.

Subject/Index Terms

• TRT Terms: Damping (Physics); Filters; Frequency response; Least squares method; Motor vehicle bodies
• Uncontrolled Terms: Interior
• Old TRIS Terms: Automobile bodies
• Subject Areas: Highways; Vehicles and Equipment;

Filing Info

• Accession Number: 00487954
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: ISVR-TR-165
• Files: TRIS
• Created Date: Sep 30 1989 12:00AM