Frequency and Angular Resolution for Measuring, Presenting and Predicting Loudspeaker Polar Data

The spherical polar loudspeaker data available today are usually measured with such a coarse resolution that only rough estimates of the performance of sound systems can be predicted by applying these data. Complex, spherical polar data with higher angular and frequency resolutions than used today are needed to represent and predict the sound fields from single and multiple sound sources more accurately. The relationship between measurement resolution and the accuracy of presented or predicted polar and frequency responses from single or arrayed loudspeakers is described. Plane and spherical polar data measurement principles and systems, in terms of specific levels of accuracy, are also discussed. The presented material consists of research the authors have done for the AES Standards Committee SC-04-03, working group on loudspeaker modeling and measurement, toward a goal set by that working group and approved by the AES Standards Committee. The work is a continuation of AES project AES-X07 and is presented to provide background for a Call for Comment on Draft AES-5id-xxxx, AES information document for Room acoustics and sound reinforcement systems - Loudspeaker modeling and measurement - Frequency and angular resolution for measuring, presenting and predicting loudspeaker polar data.