Evaluation of changes in stereophonic imagery during progressive optimization of loudspeaker configuration in critical listening rooms

While simple approaches to the configuration of loudspeakers in critical listening rooms are well known, there is no standardized practice for optimising loudspeaker positions that is based upon improvements in the perceived quality of the stereophonic imagery associated with adjustments to the loudspeaker positions. As the influence of the acoustical response of the reproduction space on stereophonic imagery is not so simple to predict, a pragmatic solution to this problem has been developed and is growing in popularity, particularly among recording engineers. This method utilising changes in stereophonic image quality that occur when moving either the listening position or loudspeaker positions in an effort to find an optimum configuration within a listening room. While the method gives good practical results, there is as yet no explanation as to how or why the method works, and no consensus regarding the characterisation of changes in auditory imagery to which listeners must attend. To provide a more scientific foundation for explaining this method, the steps involved in optimisation were documented for a test case, and the changes in the binaural responses during the adjustment of loudspeaker positions were analysed in relation to loudspeaker configurations that were preferred by a group of ten listeners.