The control of excessively long decays in a listening room with strong low-frequency modes is problematic, expensive, and sometimes impossible with conventional passive means. A systematic methodology is presented to design active modal equalization able to selectively reduce the mode decay rate of a loudspeaker-room system at low frequencies in the vicinity of a sound engineer's listening location. Modal equalization is able to increase the rate of initial sound decay at mode frequencies, and can be used with conventional magnitude equalization to optimize the reproduced sound quality. Two methods of implementing active modal equalization are proposed. The first modifies the primary sound such that the mode decay rates are controlled. The second uses separate secondary radiators and controls the mode decays with additional sound fed into the secondary radiators. Case studies are presented of implementing active modal control according to the first method.

Authors: Mäkivirta, Aki; Antsalo, Poju; Karjalainen, Matti; Välimäki, Vesa
Affiliations: Genelec Oy, lisalmi, Finland ; Helsinki University of Technology, Laboratory of Acoustics and Audio Signal Processing, HUT, Espoo, Finland(See document for exact affiliation information.)
JAES Volume 51 Issue 5 pp. 324-343; May 2003
Publication Date: May 15, 2003 Import into BibTeX
Permalink: https://www.aes.org/e-lib/browse.cfm?elib=12226

Click to purchase paper as a non-member or login as an AES member. If your company or school subscribes to the E-Library then switch to the institutional version. If you are not an AES member and would like to subscribe to the E-Library then Join the AES!

This paper costs $33 for non-members and is free for AES members and E-Library subscribers.

Learn more about the AES E-Library

E-Library Location: (CD aes20)   /jrnl2003/2003/0324.pdf

Start a discussion about this paper!