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Evaluating the Accuracy of the Ambisonic Reproduction of Measured Soundfields

Clapp, Sam; Guthrie, Anne; Braasch, Jonas; Xiang, Ning

FG Audiokommunikation

A spherical microphone array can encode a measured soundfield into its spherical harmonic components. Such an array will be subject to limitations on the highest spherical harmonic order it can encode and encoding accuracy at different frequencies. Ambisonics is a system designed to reproduce the spherical harmonic components of a measured or virtual soundfield using multiple loudspeakers. In ambisonic systems, the size of the sweet spot is wavelength dependent, and thus decreases in size with an increase in frequency. This paper examines how to reconcile the limitations of the recording and playback stages to arrive at the optimum ambisonic decoding scheme for a given spherical array design. In addition, binaural models are used to evaluate these systems perceptually.