Uppsala universitet

Compensation of Loudspeaker-Room Responses in a Robust MIMO Control Framework.

Lars-Johan Brännmark, Adrian Bahne , and Anders Ahlén

IEEE Transactions on Audio, Speech, and Language Processing , Vol. 21, No. 6, June 2013, pp. 1201-1216.
© 2013 IEEE


Abstract:
A new multichannel approach to robust broadband loudspeaker–room equalization is presented. Traditionally, the equalization (or room correction) problem has been treated primarily by single-channel methods, where loudspeaker input signals are prefiltered individually by separate scalar filters.

Single-channel methods are generally able to improve the average spectral flatness of the acoustic transfer functions in a listening region, but they cannot reduce the variability of the transfer functions within the region. Most modern audio reproduction systems, however, contain two or more loudspeakers, and in this paper we aim at improving the equalization performance by using all available loudspeakers jointly.

To this end we propose a polynomial based MIMO formulation of the equalization problem. The new approach, which is a generalization of an earlier single-channel approach by the authors, is found to reduce the average reproduction error and the transfer function variability over a region in space.

Moreover, pre-ringing artifacts are avoided, and the reproduction error below 1000 Hz is significantly reduced with an amount that scales with the number of loudspeakers used.

Related publications:
PhD Thesis by Lars-Johan Brännmark

PhD Thesis by Adrian Bahne

Paper in IEEE SP 2013 on symmetric loudspeaker-room equalization utilizing a pairwise channel similarity criterion.

Paper in IEEE SP 2009 on spatially robust audio compensation for single channels.


| Audio research at Signals and Systems | Main entry in list of publications |
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