Comb Filters

Comb filters are extremely basic building blocks for digital audio effects, as we will soon see. The acoustic echo simulation depicted in Fig.1.8 on page is one instance of a comb filter. This section presents the two basic comb-filter types, feedforward and feedback, and carries out a frequency-response analysis.

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Subsections

• Feedforward Comb Filters
• Feedback Comb Filters
• Feedforward Comb Filter Amplitude Response
• Feedback Comb Filter Amplitude Response
• Filtered-Feedback Comb Filters
• Equivalence of Parallel Combs to TDLs
• Equivalence of Series Combs to TDLs
• Time Varying Comb Filters

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Order a Hardcopy of Physical Audio Signal Processing

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Next: Feedforward Comb Filters

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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.