Sean Browne
M.S., Music Engineering Technology
June 2001

Hybrid Reverberation Algorithm Using Truncated
Impulse Response Convolution and Recursive Filtering

Table of Contents

1. Introduction

2. Reverberation Introduction

Artificial Reverberation: Impulse Response Convolution

  • Measuring Impulse Response
    - Geometrical Acoustics
    - Acoustic Measurement
  • Convolution Techniques
    - Direct Linear FIR
    - Direct Frequency
    - Overlap and Add
    - Overlap and Save
    - Minimum Delay Block Convolution
  • Pertinent Transforms

Artificial Reverberation: filtering

  • Inverse Comb Filter
  • Comb Filter
  • All-Pass Filters
  • Implementation

Measuring Reverb Quality

  • Frequency Density
  • Time Density
  • Energy Decay Relief

3. Hybrid Model Introduction
  • Implementation
  • Impulse Response Truncation
    - Time Based Truncation
    - Windowing
    - Equalization

4. Hybrid Model Design
  • Truncation
  • Convolution
  • Windowing
  • Reverb Tail
  • Equalization

5. Testing
  • Source Material
  • Time-Frequency Comparison
  • ABX testing

6. Conclusion

References