Further Extensions for FDN Reverberation

Specific low-frequency modes (``early resonances'') -- do we want them?

• Early reflections do some shaping of low-frequency response
• For concert halls, low-frequency resonances and anti-resonances are typically eliminated as much as possible by parametric equalizers
• Perhaps ``unnaturally flat'' at low frequencies is ideal
• `Small-box reverberators'' such as the violin body or vocal tract require faithful LF resonators (formants important)

Perceptual studies say reverberation time should be independently adjustable in at least three frequency bands Householder FDN = digital waveguide network (DWN) with one scattering junction