The University of Southampton
University of Southampton Institutional Repository

An investigation into an empirically designed passive sound absorber for use in recording studio control rooms

An investigation into an empirically designed passive sound absorber for use in recording studio control rooms
An investigation into an empirically designed passive sound absorber for use in recording studio control rooms

The purpose of the research is to investigate how an empirically designed sound absorber works. Particular attention is given to its performance below 400 Hz.

Anecdotal evidence regarding its performance is ratified through in situ measurements of a recently built studio, with the results showing that the room exhibits little spatial variation in low frequency reverberant energy.

Measurements made at different stages of room construction show that the short reverberation time in a room in which the absorber is used is not directly related to the surface area of porous absorbent present. A Sabine diffuse field adsorption coefficient model alone is unable to account for the behaviour of the absorber. The multi-layer absorbent wall used in the design is shown to be effective below 100 Hz by virtue of damped resonances within its structure.

Through experimental and numerical investigations, the attenuation of sound as it propagates past the absorber when implemented on the side wall of a duct is shown to be highly dependent on the wall construction. Large transmission losses are evident when the absorber presents a particular surface normal acoustic impedance. The results from a theoretical model suggest that the attenuation is caused by an acoustic surface wave. Diffraction is noted, though significant effects are not evident at the low frequencies of interest. Filtering effects are also restricted to high frequencies. All results indicate that there is no 'trapping' of sound at low frequencies.

A hypothesis relating to the normal incidence absorption coefficient of the absorber is ratified by using absorbent Finite Elements in a numerical model. Though secondary to the absorption noted at odd integer multiples of ¼ wavelength, further research could lead to a new design of modular low frequency absorber.

University of Southampton
Colam, Stuart
Colam, Stuart

Colam, Stuart (2002) An investigation into an empirically designed passive sound absorber for use in recording studio control rooms. University of Southampton, Doctoral Thesis.

Record type: Thesis (Doctoral)

Abstract

The purpose of the research is to investigate how an empirically designed sound absorber works. Particular attention is given to its performance below 400 Hz.

Anecdotal evidence regarding its performance is ratified through in situ measurements of a recently built studio, with the results showing that the room exhibits little spatial variation in low frequency reverberant energy.

Measurements made at different stages of room construction show that the short reverberation time in a room in which the absorber is used is not directly related to the surface area of porous absorbent present. A Sabine diffuse field adsorption coefficient model alone is unable to account for the behaviour of the absorber. The multi-layer absorbent wall used in the design is shown to be effective below 100 Hz by virtue of damped resonances within its structure.

Through experimental and numerical investigations, the attenuation of sound as it propagates past the absorber when implemented on the side wall of a duct is shown to be highly dependent on the wall construction. Large transmission losses are evident when the absorber presents a particular surface normal acoustic impedance. The results from a theoretical model suggest that the attenuation is caused by an acoustic surface wave. Diffraction is noted, though significant effects are not evident at the low frequencies of interest. Filtering effects are also restricted to high frequencies. All results indicate that there is no 'trapping' of sound at low frequencies.

A hypothesis relating to the normal incidence absorption coefficient of the absorber is ratified by using absorbent Finite Elements in a numerical model. Though secondary to the absorption noted at odd integer multiples of ¼ wavelength, further research could lead to a new design of modular low frequency absorber.

Text
841572.pdf - Version of Record
Available under License University of Southampton Thesis Licence.
Download (52MB)

More information

Published date: 2002

Identifiers

Local EPrints ID: 464632
URI: http://eprints.soton.ac.uk/id/eprint/464632
PURE UUID: 9a93dd7b-6068-4925-96ac-574d12ec1fe3

Catalogue record

Date deposited: 04 Jul 2022 23:52
Last modified: 05 Jul 2022 02:40

Export record

Contributors

Author: Stuart Colam

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×