FDN Reverberation

Feedback Delay Networks (FDN) were introduced earlier in §1.7. An example is shown in Fig.1.23 on page . After a brief historical summary, this section will cover some practical considerations for the use of FDNs as reverberators.

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Subsections

• History of FDNs for Artificial Reverberation
• Choice of Lossless Feedback Matrix
  • Householder Feedback Matrix
  • Most General Lossless Feedback Matrices
  • Triangular Feedback Matrices
  
  
• Choice of Delay Lengths
  • Mean Free Path
  • Mode Density Requirement
  
  
• Achieving Desired Reverberation Times
• Delay-Filter Design
  • First-Order Delay-Filter Design
  
  
• Tonal Correction Filter
• FDNs as Digital Waveguide Networks
• Further Extensions
  • Spatialization of Reverberant Reflections
  • Distribution of Mode Frequencies
  • Reverberation Time vs. Frequency
  • Digital Waveguide Reverberators
  • The Digital Waveguide Mesh for Reverberation
  • Time Varying Reverberators

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written by Julius Orion Smith III
Julius Smith's background is in electrical engineering (BS Rice 1975, PhD Stanford 1983). He is presently Professor of Music and Associate Professor (by courtesy) of Electrical Engineering at Stanford's Center for Computer Research in Music and Acoustics (CCRMA), teaching courses and pursuing research related to signal processing applied to music and audio systems. See http://ccrma.stanford.edu/~jos/ for details.