Technical Booklet G Resistance to the Passage of Sound·Page 119·B2.6
Multiple source positions and level difference averaging
The sound source should be moved to at least two positions in the source room, with level differences from each position arithmetically averaged to determine the overall level difference D as defined in BS EN ISO 140-4.
The sound source should now be moved to the next position in the source room and the above procedure repeated to determine another level difference. At least two positions should be used for the source. The level differences obtained from each source position should be arithmetically averaged to determine the level difference, D as defined in BS EN ISO 140-4.
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