The Measurement of Directional Stage Support in a Drama Theatre: Quantifying the Acoustic Effect of a Set

The acoustic environment of an auditorium stage can enhance the ability of musicians or actors to hear each other clearly. This is assessed through a set of parameters called ‘stage support‘. Stage support parameters are conventionally measured using an omnidirectional source and microphone separated by 1 m on the stage. Various stage support parameters are derived from energy ratios of the direct and reflected (or reverberant) sound in the impulse response from source to microphone. The present paper examines the possibility of assessing the directional characteristics of the reflected soundfield by using a multidirectional microphone. Measurements were made in the Sydney Theatre Company's ‘Sydney Theatre’ with and without a stage set. The microphone used allows first order spherical harmonic decomposition of the soundfield, which was transformed to cardioid components for orthogonal directions (upstage, downstage, left, right, up and down), as well as for horizontal rotations of the cardioid microphone. These were used to calculate directional stage support values. Results demonstrate the potential of this simple extension of standard stage support measurement by showing the acoustical effect of the set.