Experimental Study of Various Methods for Low Frequency Spatial Audio Reproduction Over Loudspeakers

In previous work it was shown that, at low frequencies, a number of audio reproduction techniques, including the stereo sine law, stereo tangent law, head-tracked sine law (or Compensated Amplitude Panning) and crosstalk cancellation all form a subset of first order Ambisonics and can therefore be analysed under one generalised framework. This paper expands and validates these results through objective experiments in an anechoic environment. For each of the spatial audio techniques the spherical harmonic components of the reproduced sound field of a single virtual source, as well as the reproduced binaural cues, are analysed and compared to those of an equivalent real source. The results of these measurements are in good agreement with the theoretical advances previously developed further validating, at low frequencies, the link between the otherwise disparate panning laws, binaural techniques and soundfield reconstruction approaches to spatial audio.