Active Barycentric Beamformed Stereo Upmixing

This paper presents several novel techniques for stereo to multichannel upmixing under barycentric constraints and beamformer formulations in the short-time Fourier transform (STFT) domain. We derive optimal solutions to center channel extraction and power-averaged monoization problems for a barycentric weighted mid-side decomposition. We then generalize passive multichannel upmixing via an active pan-potted barycentric beamformer formulation with sparse Chebyshev polynomial directivity. Experiments analyze center channel leakage, evaluate subjective listening tests, and render sample multichannel upmixes over varied speaker arrangements.