Grouped Feedback Delay Networks for Modeling of Coupled Spaces

Computationally-Efficient Simulation of Late Reverberation for Inhomogeneous Boundary Conditions and Coupled Rooms

“…Thus, without further evaluation, the current method is suited for typical indoor scenarios with rooms connected by doors, reflecting a class of highly relevant acoustic conditions (e.g., [29]). Future research might be directed to a more accurate simulation of the underlying acoustic coupling by, e.g., using coupled or grouped FDNs [63]. Moreover, the current spatial mapping of two (or more) discrete reverberation processes, which so far accounts for the direction-and frequency-dependent reverberation level, might be extended to anisotropic reverberation times (e.g., [16]) also suited to account for effects of coupled sub-volumes.…”

Grouped Feedback Delay Networks With Frequency-Dependent Coupling

“…In [18], the derivation of the orthonormal coupled mixing matrix was extended to an arbitrary number of coupled rooms. It was shown that a coupled feedback matrix, parameterized by a coupling coefficient matrix and individual unitary feedback matrices for each room, is unitary if the coupling coefficient matrix is unitary by design.…”

“…The diagonal filter response is flat, and the off-diagonal response is a notch filter whose cut-off frequency can be controlled by the parameter β. It can be implemented in real-time and has been incorporated into a GFDN plugin [23]. Higher-order causal filters for more than two coupled FDNs can be designed by following the rules of Theorem 3 (see Appendix B).…”

“…Assuming a circular aperture connecting the rooms, the aperture radius between the two rooms is increased in steps. This, along with the room area and absorption coefficients, is used to calculate the coupling coefficients according to (23). The frequency response of the Filter Feedback Matrix's (FFM) coupling matrix is shown in Fig.…”

“…The GFDN was used to model coupled rooms and a room made of different materials where multiple concurrent decay times are observed. The discussion on coupled room modeling was further elaborated in [18] by comparing the GFDN's behavior to measurements. Similarly, a coupled volume extension to the scattering delay network was proposed recently in [19].…”