Observatorio de I+D+i UPM

Memorias de investigación
Research Publications in journals:
Influence of loudspeaker directivity and measurement geometry on direct acoustic levels over facades for acoustic insulation test with the international standard ISO140-5
Year:2012
Research Areas
  • Engineering
Information
Abstract
The International Standard ISO 140-5 on field measurements of airborne sound insulation of façades establishes that the directivity of the measurement loudspeaker should be such that the variation in the local direct sound pressure level (DSPL) on the sample is DSPL < 5 dB (or DSPL < 10 dB for large façades). This condition is usually not very easy to accomplish nor is it easy to verify whether the loudspeaker produces such a uniform level. Direct sound pressure levels on the ISO standard façade essentially depend on the distance and directivity of the loudspeaker used. This paper presents a comprehensive analysis of the test geometry for measuring sound insulation and explains how the loudspeaker directivity, combined with distance, affects the acoustic level distribution on the façade. The first sections of the paper are focused on analysing the measurement geometry and its influence on the direct acoustic level variations on the façade. The most favourable and least favourable positions to minimise these direct acoustic level differences are found, and the angles covered by the façade in the reference system of the loudspeaker are also determined. Then, the maximum dimensions of the façade that meet the conditions of the ISO 140-5 standard are obtained for the ideal omnidirectional sound source and the piston radiating in an infinite baffle, which is chosen as the typical radiation pattern for loudspeakers. Finally, a complete study of the behaviour of different loudspeaker radiation models (such as those usually utilised in the ISO 140-5 measurements) is performed, comparing their radiation maps on the façade for searching their maximum dimensions and the most appropriate radiation configurations.
International
Si
JCR
Si
Title
Applied Acoustics
ISBN
0003-682X
Impact factor JCR
1,05
Impact info
Volume
73
Journal number
From page
440
To page
453
Month
ABRIL
Ranking
Participants
  • Autor: Jose Luis Sanchez Bote (UPM)
  • Autor: Antonio Pedrero Gonzalez (UPM)
  • Autor: Juan Jose Gomez Alfageme (UPM)
Research Group, Departaments and Institutes related
  • Creador: Grupo de Investigación: Grupo de Aplicaciones en Sonido y Vídeo
  • Departamento: Ingeniería Audiovisual y Comunicaciones
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