Soundfield control for consumer device testing

This paper covers the theory, measurement and analysis of a constructed reference system to capture and acoustically reconstruct a spatial soundfield for device testing. Using a rigid sphere microphone array, a framework is presented for numeric and visual representation of the multidimensional system performance. This is used to compare the measured acoustic spatial recreation of a practical 30 channel dodecahedral speaker array to that of a theoretically optimal third order system. We consider the excess noise gain introduced to compensate for the imperfect realization. Results show the theoretical impact of the pragmatic dodecahedral speaker geometry is similar in magnitude to the impact of acoustic considerations such as scattering and use of real speakers. Whilst the speaker arrangement is important, in the context of system design, it is not the most critical factor in a cost constrained design. This work provides a contribution towards bridging the gap between academic soundfield theory and the research challenges for a present high impact application.