Binaural rendering is typically assessed via timbre; localization accuracy, while its intrinsic spatial resolution remains rarely quantified. This paper proposes a perceptual evaluation method based on Minimum Audible Angle (MAA) measurements to estimate the azimuthal just-noticeable difference (JND) introduced by binaural rendering algorithms. We systematically compared several rendering algorithms across eight reference azimuths using two participant-allocation paradigms. The results show that spatial resolution is significantly influenced by Ambisonic order; choice of the rendering alrorithm, with MAA thresholds systematically decreasing as the truncation order increases. Furthermore, the propsed method successfully captures physiological spatial characteristics ; identifies resolution limits imposed by reference angles. While both participant-allocation paradigms yield consistent qualitative trends, the repeated-measures design provides superior data stability. These findings demonstrate that the proposed MAA-based method is an effective tool for quantifying the spatial resolution of binaural rendering algorithms.
