Active diffusers : some prototypes and 2D measurements

Xiao, L, Cox, TJ ORCID: and Avis, MR 2005, 'Active diffusers : some prototypes and 2D measurements' , Journal of Sound and Vibration, 285 (1-2) , pp. 321-339.

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Diffusing devices are used to improve room acoustics in a wide variety of applications. The dispersion generated by current diffuser technologies is often limited to mid-to-high frequencies because low-frequency diffusers are usually too large to be easily accommodated. To extend the bandwidth of diffusers to a lower frequency a new approach is proposed, that is to use active control technology. In particular, active impedance techniques have been exploited to create non-absorbing diffusers, and hybrid structures that partly absorb while dispersing any reflected sound. This paper presents results mostly from a feedforward structure. It is found that achieving active dispersion without absorption other a worthwhile bandwidth can be more difficult than achieving active absorption due to the more complex target impedance that the controller needs to learn. Measurements on polar responses provide evidence that the active diffusers can achieve wider bandwidth dispersion. Boundary element modelling has enabled the design of these structures to be examined in more application-realistic set-ups.

Item Type: Article
Themes: Subjects / Themes > Q Science > QC Physics > QC221-246 Acoustics - Sound
Subjects outside of the University Themes
Schools: Schools > School of the Built Environment
Schools > School of Computing, Science and Engineering > Salford Innovation Research Centre
Journal or Publication Title: Journal of Sound and Vibration
Publisher: Elsevier
Refereed: Yes
ISSN: 1095-8568
Depositing User: H Kenna
Date Deposited: 10 Sep 2007 10:44
Last Modified: 16 Feb 2022 07:46

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