Configuring SpADE: practical considerations influencing the design of a three-dimensional multi-channel listening environment

The Digital Media and Arts Research Centre’s (DMARC) Spatialisation and Auditory Display Environment (SpADE) is a sound system comprising a 32-channel circular loudspeaker array encompassing more than 13 multi-channel configurations designed for auditory research. The environment in which SpADE resides has recently been evaluated to determine whether the space meets listening room standards.Given the absence of a listening room standard for three- dimensional (3D) multi-channel reproduction, the ITU-R BS.1116-1 standard has been applied. This standard is recommended for 5- and 7-channel reproduction focusing on the horizontal plane and while the effects of the elevated speakers are not tested, it is the most comprehensive listening room standard currently available. The use of this listening room standard in SpADE has two primary functions: (1) to offer tight control of the acoustic variables which ensure that perceptual research conducted in the room is devoid of acoustic distortions which may detrimentally affect the validity of the tests, (2) to allow composers of electroacoustic music to undertake creative work in an acoustic environment which allows compositions to be encoded accurately without encoding the room deficiencies, thereby ensuring accurate translatability.This paper details the methodology used to measure the room using acoustic software and how this information was mapped against the ITU-R standard. It further explains how this process facilitated the creation of acoustic treatment which targets the specific problems in SpADE and the design of this treatment is discussed. Finally, the room was re-measured to determine the effectiveness of the treatment and final adjustments were made to bring the room within the guidelines set out in ITU-R BS.1116-1.