Methods for 2nd Order Spherical Harmonic Spatial Encoding in Digital Waveguide Mesh Virtual Acoustic Simulations

The Digital Waveguide Mesh (DWM) is a numerical simulation technique that has been shown to be suitable for modelling the acoustics of enclosed spaces. Previous work considered an approach using an array of spatially distributed receivers based on sound intensity probe theory to capture spatial room impulse responses (RIRs) from the DWM. A suitable process to facilitate spatial encoding of the DWMinto second-order spherical harmonics has also been explored. The purpose of this paper is to introduce a new alternative processing scheme based on the Blumlein Difference Technique. Both the previous and currently presented techniques are newly formulated with the main processing in the frequency domain. In addition the ability of the newly proposed technique for capturing the 2^nd order components is confirmed and further processing of the receiver array is considered to extend the usable frequency range.