Using Vbap-derived Panning Functions for 3d Ambisonics Decoding

In this contribution we will explain the derivation of panning functions from the vector base amplitude panning (VBAP) technology for 3-dimensional Ambisonics decoding. VBAP turned out to be a robust method for presenting virtual acoustic sources. Each virtual source to be played back using VBAP has to be described by a monophonic signal and a 3-dimensional position as parameter. In opposite to this, Ambisonics describes an entire sound field where no explicit sources are given. This contribution shows how to apply the VBAP methodology to Ambisonics signals. In particular, we present the mathematical derivation to calculate a decoding matrix from given panning functions. Informal listening tests show that the proposed decoding approach shows much better localisation than Ambisonics decoding using mode matching for nonuniform loudspeaker setups.