Includes bibliographical references (pages 339-343) and index.

Preface


About the Authors


Aim and Scope of Book


Introduction and Fundamentals


Understanding Sound and Digital Audio


Working with Decibels


Level Measurements


Representing and Understanding Digital Signals


Representing Complex Numbers


Frequency and Time-Frequency Representations


Aliasing


Modifying and Processing Digital Signals


The Z Transform and Filter Representation


Digital Filter Example


Nonlinear and Time-Varying Effects


Delay Line Effects


Delay


Theory


Basic Delay


Delay with Feedback


Other Delay Types


Slapback Delay


Multitap Delay


Ping-Pong Delay


Implementation


Basic Delay


Variations


Delay Line Interpolation


Code Example


Applications


Vibrato Simulation


Theory


Interpolation


Implementation


Low-Frequency Oscillator


Parameters


Code Example


Applications


Flanging


Theory


Principle of Operation


Basic Flanger


Low-Frequency Oscillator


Flanger with Feedback


Stereo Flanging


Properties


Common Parameters


Depth (or Mix)


Delay and Sweep Width


Speed and Waveform


Feedback (or Regeneration)


Inverted Mode (or Phase)


Implementation


Buffer Allocation


Interpolation


Code Example


Applications


Resonant Pitches


Avoiding Disappearing Instruments


Flanging versus Chorus


Chorus


Theory


Basic Chorus


Low-Frequency Oscillator


Pitch-Shifting in the Chorus


Multivoice Chorus


Stereo Chorus


Properties


Common Parameters


Depth (or Mix)


Delay and Sweep Width


Speed and Waveform


Number of Voices


Other Variations


Summary: Flanger and Chorus Compared


Filter Design


Filter Construction and Transformation


Simple, Prototype Low-Pass Filter


High-Order Prototype Low-Pass Filter


Changing the Gain at the Cutoff Frequency


Shifting the Cutoff Frequency


Creating a Shelving Filter


Inverting the Magnitude Response


Simple Low-Pass to Band Pass Transformation


Popular IIR Filter Design


Low Pass


High Pass


Low Shelf


High Shelf


Gain at Bandwidth


Band Pass Filters


Band Stop Filters


Peaking and Notch Filters


The Allpass Filter


Applications of Filter Fundamentals


Exponential Moving Average Filter


Loudspeaker Crossovers


Filter Effects


Equalization


Theory


Two-Knob Tone Controls


Three-Knob Tone Controls


Presence Control


Loudness Control


Graphic Equalizers


Bands in a Graphic Equalizer


Parametric Equalizers


Summary


Implementation


General Notes


Tone Control Architecture


Calculating Filter Coefficients


Presence and Loudness Architecture


Graphic Equalizer Architecture


Parametric Equalizer Architecture


Code Example


Applications


Graphic Equalizer Application


Parametric Equalizer Application


Wah-Wah


Theory


Basis in Speech


Basic Wah-Wah


Auto-Wah


Tremolo-Wah


Other Variations


Implementation


Filter Design


Low-Frequency Oscillator


Envelope Follower


Analog Emulation


Phaser


Theory


Basic Phaser


Low-Frequency Oscillator


Phaser with Feedback


Stereo Phaser


Implementation


Allpass Filter Calculation


Alternate Implementation


LFO Waveform


Analog and Digital Implementations


Common Parameters


Code Example


Amplitude Modulation


Tremolo


Theory


Low-Frequency


Oscillator


Properties


Implementation


Audio Rate and Control Rate


Code Example


Ring Modulation


Theory


Modulation in the Frequency Domain


Perception


w-Frequency Oscillator


Variations


Implementation


Code Example


Applications


Dynamics Processing


Dynamic Range Compression


Theory


Compressor Controls


Signal Paths


The Gain Stage


The Gain Computer


Level Detection


RMS Detector


Peak Detector


Level-Corrected Peak Detectors


Implementation


Feedback and Feedforward Design


An Alternate Digital Feedback Compressor


Detector Placement


Code Example


Application


Artifacts


Summary


Noise Gates and Expanders


Theory and Implementation


Applications


Overdrive, Distortion, and Fuzz


Theory


Characteristic Curve


Hard and Soft Clipping


Input Gain


Symmetry and Rectification


Harmonic Distortion


Intermodulation Distortion


Analog Emulation


Implementation


Basic Implementation


Aliasing and Oversampling


Filtering


Common Parameters


Tube Sound Distortion


Code Example


Applications


Expressivity and Spectral Content


Sustain


Comparison with Compression


The Phase Vocoder


Phase Vocoder Theory


Overview


Windowing


Analysis: Fast Fourier Transform


Interpreting Frequency Domain Data


Target Phase, Phase Deviation, and Instantaneous Frequency


Synthesis: Inverse Fast Fourier Transform


Overlap-Add


Filterbank Analysis Variant


Oscillator Bank Reconstruction Variant


Phase Vocoder Effects


Robotization


Robotization Code Example


Whisperization


Whisperization Code Example


Time Scaling


Time-Scaling Resynthesis


Pitch Shifting


Code Example


Phase Vocoder Artifacts


Spatial Audio


Theory


Panorama


Precedence


Vector Base Amplitude Panning


Ambisonics


Wave Field Synthesis


The Head-Related Transfer Function


ITD Model


ILD Model


Implementation


Joint Panorama and Precedence


Ambisonics and Its Relationship to VBAP


Implementation of WFS


HRTF Calculation


Applications


Transparent Amplification


Surround Sound


Sound Reproduction Using HRTFs


The Doppler Effect


A Familiar Example


Derivation of the Doppler Effect


Simple Derivation of the Basic Doppler Effect


General Derivation of the Doppler Effect


Simplifications and Approximations


Implementation


Time-Varying Delay Line Reads


Multiple Write Pointers


Code Example


Applications


Reverberation


Theory


Sabine and Norris-Eyring Equations


Direct and Reverberant Sound Fields


Implementation


Algorithmic Reverb


Schroeder's Reverberator


Moorer's Reverberator


Generating Reverberation with the Image Source Method


Background


The Image Source Model


Modeling Reflections as Virtual Sources


Locating the Virtual Sources


The Impulse Response for a Virtual Source


Convolutional Reverb


Convolution and Fast Convolution


Block-Based Convolution


Physical Meaning


Other Approaches


Applications


Why Use Reverb?


Stereo Reverb


Gated Reverb


Reverse Reverb


Common Parameters


Audio Production


The Mixing Console


The Channel Section


The Master Section


Metering and Monitoring


Basic Mixing Console


Signal Flow and Routing


Inserts for Processors, Auxiliary Sends for Effects


Subgroup and Grouping


Digital versus Analog


Latency


Digital User Interface Design


Sound Quality


Do You Need to Decide?


Software Mixers


Digital Audio Workstations


Common Functionality of Computer-Based DAWs


MIDI and Sequencers


Audio Effect Ordering


Noise Gates


Compressors and Noise Gates


Compression and EQ


Reverb and Flanger


Reverb and Vibrato


Delay Line Effects


Distortion


Order Summary


Combinations of Audio Effects


Parallel Effects and Parallel Compression


Sidechaining


Ducking


De-Esser Sidechain Compression for Mastering


Multiband Compression


Dynamic Equalization


Combining LFOs with Other Effects


Discussion


Building Audio Effect Plug-Ins


Plug-In Basics


Programming Language


Plug-In Properties


The JUCE Framework


Theory of Operation


Callback Function


Managing Parameters


Initialization and Cleanup


Preserving State


Example: Building a Delay Effect in JUCE


Required Software


Creating a New Plug-In in JUCE


Opening Example Plug-Ins


File Overview


PluginProcessor.h


Declaration and Methods


Variables


PluginProcessor.cpp


Audio Callback


Initialization


Managing Parameters


Cleanup


PluginEditor.h


PluginEditor.cpp


Initialization


Managing Parameters


Resizing


Cleanup


Summary


Advanced Topics


Efficiency Considerations


Thread Safety


Conclusion


References


Index

"Audio Effects: Theory, Implementation and Application explores digital audio effects relevant to audio signal processing and music informatics. It supplies fundamental background information on digital signal processing, focusing on audio-specific aspects that constitute the building block on which audio effects are developed. The text integrates theory and practice, relating technical implementation to musical implications. It can be used to gain an understanding of the operation of existing audio effects or to create new ones. In addition to delivering detailed coverage of common (and unusual) audio effects, the book discusses current digital audio standards, most notably VST and AudioUnit. Source code is provided in C/C++ and implemented as audio effect plug-ins with accompanying sound samples. Each section of the book includes study questions, anecdotes from the history of music technology, and examples that offer valuable real-world insight, making this an ideal resource for researchers and for students moving directly into industry"-- Provided by publisher.