Limitations of Point-Source Sub-woofer array models for Live Sound

摘要

This paper examines the validity of applying simple models to the kind of, highly configurable, low frequency arrays typically used for live sound. Measurements were performed on a single full sized touring sub-woofer array element at different positions within a number of different array configurations. It was discovered that radiation was rarely omnidirectional and in some cases more than 20dB from being so. Additionally the in-situ polar response significantly differed from that obtained with the cabinet in isolation, the degree of difference (2-10dB) was strongly dependent on array type and element position. For compact arrays we demonstrate, via the application of the 'acoustic centre' concept, that even when elemental radiation approaches omnidirectional behaviour some array configurations are particularly susceptible to errors arising from commonly applied assumptions.