000229162 001__ 229162
000229162 005__ 20190617200527.0
000229162 022__ $$a1610-1928
000229162 02470 $$2ISI$$a000417126700015
000229162 0247_ $$a10.3813/AAA.919132$$2doi
000229162 037__ $$aARTICLE
000229162 245__ $$aOn the Optimisation of Multi-Degree-of-Freedom Acoustic Impedances of Low-Frequency Electroacoustic Absorbers for Room Modal Equalisation
000229162 269__ $$a2017
000229162 260__ $$c2017
000229162 300__ $$a12
000229162 336__ $$aJournal Articles
000229162 500__ $$a<span class="__dimensions_badge_embed__" data-doi="10.3813/AAA.919132"></span><script async src="https://badge.dimensions.ai/badge.js" charset="utf-8"></script>
000229162 520__ $$aLow-frequency electroacoustic absorbers have recently been developed as a solution for the modal equalisation. Firstly investigated in waveguides, the technique consists in matching the acoustic impedance at a closed-box loudspeaker diaphragm to the characteristic acoustic impedance of air. Extending the results in a duct to rooms brings up several challenges. Some parameters, such as the position and orientation of absorbers, the total area, as well as the acoustic impedance achieved at the diaphragms may influence the performance, especially in terms of modal decay time reduction. In this paper, the optimal values of a purely resistive acoustic impedance at an absorber diaphragm, whose area varies, are first investigated under normal incidence and grazing incidence in a finite-length waveguide. The optimal acoustic resistance values are then investigated for a given position, orientation, and total area of absorbers in rooms of different size. From these results, the target acoustic impedances with multiple degrees of freedom are defined with a view to assign to the absorber diaphragms. These impedances are then optimised from a global criterion, so that these impedances approach at best the different optimal resistance values found to minimise the modal decay times. Finally, an experimental evaluation of the performance of the electroacoustic absorber in a waveguide is provided.
000229162 6531_ $$aElectroacoustic absorbers
000229162 6531_ $$aRoom modes equalization
000229162 6531_ $$aActive acoustic impedance control
000229162 6531_ $$aMultiple degree of freedom resonators
000229162 700__ $$g195222$$0246640$$aRivet, Etienne
000229162 700__ $$aKarkar, Sami
000229162 700__ $$aLissek, Hervé
000229162 773__ $$q1025-1036$$k6$$j103$$tActa Acustica united with Acustica
000229162 8560_ $$fherve.lissek@epfl.ch
000229162 8564_ $$uhttps://infoscience.epfl.ch/record/229162/files/2017_AAA_Rivet_MDOF%20optimization.pdf$$zPublisher's version$$s1887141$$yPublisher's version
000229162 909C0 $$xU10380$$0252392$$pLTS2
000229162 909CO $$qGLOBAL_SET$$pSTI$$ooai:infoscience.tind.io:229162$$particle
000229162 917Z8 $$x195222
000229162 917Z8 $$x157878
000229162 917Z8 $$x157878
000229162 917Z8 $$x157878
000229162 937__ $$aEPFL-ARTICLE-229162
000229162 973__ $$rREVIEWED$$sPUBLISHED$$aEPFL
000229162 980__ $$aARTICLE