Inversion of Loudspeaker Dynamics and Room Acoustics

Daniel Botella

Master Thesis, Uppsala University, Report UPTEC F 99010, Feb 1999.

Background:

Within the new undergraduate course Adaptive Signal Processing Project course, one of the projekt tasks which can be chosen is to investigate ways to compensate for the dynamics of loudspeakers, and if possible also to invert some of the room acoustics. This master thesis project verified the basic ideas, hardware and software tools.

Abstract:

The specifications of this project are to study how a PC could be used for compensating an audio system and what problems there are, so that a laboratory course can be launched where the students have to compensate for room acoustics and stereo dynamics.

The results of using the filtered-x LMS algorithm to compensate for a stereo are presented by compensating for two different sets of equipment. Due to the limitations of the equipment used, real time adaptation has not been attempted and audio evaluation of the solutions found has not been possible.

The results obtained suggest that a fast computer and a good microphone system will allow for good adaptive compensation of the stereo. Some further research will be needed for successful compensation of room acoustics.

Thesis Advisor:

Mikael Sternad

Related publications:

Subsequent Master Thesis by Mathias Johansson and Jonas Rutström.