Table of Contents

Copyright

Brief Table of Contents

Table of Contents

List of Figures

List of Tables

About the Authors

I. Fundamentals of Sound

Chapter 1. Audio Principles

1.1. The Physics of Sound

1.2. Wavelength

1.3. Periodic and Aperiodic Signals

1.4. Sound and the Ear

1.5. The Cochlea

1.6. Mental Processes

1.7. Level and Loudness

1.8. Frequency Discrimination

1.9. Frequency Response and Linearity

1.10. The Sine Wave

1.11. Root Mean Square Measurements

1.12. The Decibel

1.13. Audio Level Metering

Chapter 2. Measurement

2.1. Concepts Underlying the Decibel and its Use in Sound Systems

2.1.1. Converting Voltage Ratios to Power Ratios

2.1.2. The dBV

2.1.3. The Decibel as a Power Ratio

2.1.4. Finding Other Multipliers

2.1.5. The Decibel as a Power Quantity

2.1.6. Example

2.2. Measuring Electrical Power

2.2.1. Most Common Technique

2.3. Expressing Power as an Audio Level

2.3.1. Special Circumstance

2.4. Conventional Practice

2.4.1. Levels in dB

2.4.2. Practical Variations of the dBm Equations

2.5. The Decibel in Acoustics—LP, LW, and LI

2.6. Acoustic Intensity Level (LI), Acoustic Power Level (LW), and Acoustic Pressure Level (LP)

2.6.1. Acoustic Intensity Level, LI

2.6.2. Acoustic Power Level, LW

2.6.3. Acoustic Pressure Level, LP

2.7. Inverse Square Law

2.8. Directivity Factor

2.9. Ohm’s Law

2.10. A Decibel is a Decibel is a Decibel

2.11. Older References

2.12. The Equivalent Level (LEQ) in Noise Measurements

2.13. Combining Decibels

2.13.1. Adding Decibel Levels

2.13.2. Subtracting Decibels

2.13.3. Combining Levels of Uncorrelated Noise Signals

2.13.4. To Add Levels

2.13.5. To Subtract Levels

2.14. Combining Voltage

2.15. Using the Log Charts

2.15.1. The 10 Log x Chart

2.15.2. The 20 Log x Chart

2.16. Finding the Logarithm of a Number to Any Base

2.17. Semitone Intervals

2.18. System Gain Changes

2.19. The VU and the Volume Indicator Instrument

2.19.1. The VU Impedance Correction

2.19.2. How to Read the VU Level on a VI Instrument

2.19.3. Calibrating a VI Instrument

2.19.4. Reading Apparent VU Levels

2.20. Calculating the Number of Decades in a Frequency Span

Example

2.21. Deflection of the Eardrum at Various Sound Levels

Example

2.22. The Phon

2.23. The Tempered Scale

2.24. Measuring Distortion

2.25. The Acoustical Meaning of Harmonic Distortion

2.25.1. Calculating the Maximum Allowable Total Harmonic Distortion in an Arena Sound System

2.26. Playback Systems in Studios

2.26.1. Choosing an Amplifier

2.27. Decibels and Percentages

2.28. Summary

Uncited Reference

Chapter 3. Acoustic Environment

3.1. The Acoustic Environment

3.2. Inverse Square Law

3.3. Atmospheric Absorption

3.4. Velocity of Sound

3.4.1. Example

3.5. Temperature-Dependent Velocity

3.6. The Effect of Altitude on the Velocity of Sound in Air

3.7. Typical Wavelengths

3.8. Doppler Effect

Example

3.9. Reflection and Refraction

3.10. Effect of a Space Heater on Flutter Echo

3.11. Absorption

Example

3.12. Classifying Sound Fields

3.12.1. Free Fields

3.12.2. Diffuse (Reverberant) Fields

3.12.3. Semireverberant Fields

3.12.4. Pressure Fields

3.12.5. Ambient Noise Field

3.12.6. Outdoor Acoustics

3.13. The Acoustic Environment Indoors

3.13.1. The Mean Free Path (MFP)

3.13.2. Build-Up of the Reverberant Sound Field

3.14. Conclusion

Further Reading

II. Audio Electronics

Chapter 4. Components

4.1. Building Block Components

4.1.1. Resistors

4.1.2. Capacitors

4.1.3. Diodes

4.1.4. Transistors

4.1.5. Other Components

Chapter 5. Power Supply Design

5.1. High Power Systems

5.2. Solid-State Rectifiers

5.3. Music Power

5.4. Influence of Signal Type on Power Supply Design

5.5. High Current Power Supply Systems

5.6. Half-Wave and Full-Wave Rectification

5.7. Direct Current Supply Line Ripple Rejection

5.8. Voltage Regulator Systems

5.9. Series Regulator Layouts

5.10. Overcurrent Protection

5.11. Integrated Circuit (Three Terminals) Voltage Regulator ICs

5.12. Typical Contemporary Commercial Practice

5.13. Battery Supplies

5.14. Switch-Mode Power Supplies

III. Preamplifiers and Amplifiers

Chapter 6. Introduction to Audio Amplification

Chapter 7. Preamplifiers and Input Signals

7.1. Requirements

7.2. Signal Voltage and Impedance Levels

7.3. Gramophone Pick-Up Inputs

7.3.1. Ceramic Piezo-Electric Cartridges

7.3.2. Moving Magnet and Variable Reluctance Cartridges

7.3.3. Moving Coil Pick-Up Cartridges

7.4. Input Circuitry

7.5. Moving Coil Pick-up Head Amplifier Design

7.6. Circuit Arrangements

7.6.1. Step-Up Transformer

7.6.2. Systems Using Paralleled Input Transistors

7.6.3. Monolithic Super-Matched Input Devices

7.6.4. Small Power Transistors as Input Devices

7.6.5. Very Low Noise IC Op-Amps

7.6.6. Other Approaches

7.7. Input Connections

7.8. Input Switching

7.8.1. Transistor Switching

7.8.2. Diode Switching

Voltage amplifiers and controls

7.9. Preamplifier Stages

7.10. Linearity

7.10.1. Bipolar Transistors

7.10.2. Field Effect Devices

7.11. Noise Levels

7.12. Output Voltage Characteristics

7.12.1. Signal Characteristics

7.13. Voltage Amplifier Design

7.14. Constant-Current Sources and “Current Mirrors”

7.14.1. IC Solutions

7.15. Performance Standards

7.15.1. Use of ICs

7.15.2. Modern Standards

7.16. Audibility of Distortion

7.16.1. Harmonic and Intermodulation Distortion

7.16.2. Transient Defects

7.16.3. Spurious Signals

7.16.4. Mains-Borne Interference

7.17. General Design Considerations

7.18. Controls

7.18.1. Gain Controls

7.18.2. Tone Controls

7.18.3. Channel Balance Controls

7.18.4. Channel Separation Controls

7.18.5. Filters

Chapter 8. Interfacing and Processing

8.1. The Input

8.1.1. Input Sensitivity and Gain Requirements

8.1.2. Input Impedance (Zin)

8.2. Radio Frequency Filtration

8.2.1. Introduction

8.2.2. Requirement

8.3. Balanced Input

8.3.1. Definition

8.3.2. Real Conditions

8.3.3. Balancing Requirements

8.3.4. Introducing Common Mode Rejection

8.4. Subsonic Protection and High-Pass Filtering

8.4.1. Rationale

8.4.2. Subsonic Stresses

8.4.3. The Pro Approach

8.4.4. Logistics

8.4.5. Indication

8.4.6. Hi-End Approach

8.4.7. Low Approach

8.4.8. Direct Coupling

8.5. Damage Protection

8.5.1. Causes

8.5.2. Scope

8.5.3. Harmful Conditions

8.5.4. On-State Risks

8.5.5. Off-State Vulnerability

8.5.6. Occurrence Modes

8.5.7. Protection Circuitry

8.6. What Are Process Functions?

8.6.1. Common Gain Control (Panel Attenuator)

8.6.2. Remotable Gain Controls (Machine Control)

8.6.3. Remote Control Considerations

8.6.4. Compression and Limiting

8.6.5. Clipping (Overload) Considerations

8.6.6. Clip Prevention

8.6.7. Soft Clip

8.7. Computer Control

Further Reading

Chapter 9. Audio Amplifiers

9.1. Junction Transistors

9.2. Control of Operating Bias

9.3. Stage Gain

9.4. Basic Junction Transistor Circuit Configurations

9.5. Emitter–Follower Systems

9.6. Thermal Dissipation Limits

9.7. Junction Field Effect Transistors (JFETs)

9.8. Insulated Gate FETs (MOSFETs)

9.9. Power BJTs vs Power MOSFETs as Amplifier Output Devices

9.10. U and D MOSFETs

9.11. Useful Circuit Components

9.11.1. Constant Current Sources

9.11.2. Current Mirror Layouts

9.12. Circuit Oddments

9.13. Slew Rate Limiting

Uncited Reference

Chapter 10. Audio Amplifier Performance

10.1. A Brief History of Amplifiers

10.2. Amplifier Architectures

10.3. The Three-Stage Architecture

10.3.1. Two-Stage Amplifier Architecture

10.4. Power Amplifier Classes

10.4.1. Class-A

10.4.2. Class-AB

10.4.3. Class-B

10.4.4. Class-C

10.4.5. Class-D

10.4.6. Class-E

10.4.7. Class-F

10.4.8. Class-G

10.4.9. Class-H

10.4.10. Class-S

10.4.11. Variations on Class-B

10.4.12. Error-Correcting Amplifiers

10.4.13. Nonswitching Amplifiers

10.4.14. Current-Drive Amplifiers

10.4.15. The Blomley Principle

10.4.16. Geometric Mean Class-AB

10.4.17. Nested Differentiating Feedback Loops

10.5. AC- and DC-Coupled Amplifiers

10.5.1. Advantages of AC Coupling

10.5.2. Advantages of DC Coupling

10.6. Negative Feedback in Power Amplifiers

10.6.1. Some Common Misconceptions About Negative Feedback

Chapter 11. Valve (Tube-Based) Amplifiers

11.1. Valves or Vacuum Tubes

11.1.1. The Cathode

11.1.2. The Anode

11.1.3. The Control Grid

11.1.4. The Space Charge

11.1.5. Tetrodes and Pentodes

11.1.6. Valve Parameters

11.1.7. Gettering

11.1.8. Cathode and Heater Ratings

11.1.9. Microphony

11.2. Solid-State Devices

11.2.1. Bipolar Junction Transistors

11.3. Valve Audio Amplifier Layouts

11.4. Single-Ended Versus Push–Pull Operation

11.5. Phase Splitters

11.6. Output Stages

11.7. Output (Load-Matching) Transformer

11.8. Effect of Output Load Impedance

11.9. Available Output Power

Chapter 12. Negative Feedback

12.1. Amplifier Stability and Negative Feedback

12.2. Maximizing Negative Feedback

12.3. Maximizing Linearity Before Feedback

Further Reading

Chapter 13. Noise and Grounding

13.1. Audio Amplifier Printed Circuit Board Design

13.1.1. Cross Talk

13.1.2. Rail Induction Distortion

13.1.3. Mounting of Output Devices

13.1.4. Single- and Double-Sided Printed Circuit Boards

13.1.5. Power Supply Printed Circuit Board Layout

13.1.6. Power Amplifier Printed Circuit Board Layout Details

13.1.7. Audio Printed Circuit Board Layout Sequence

13.1.8. Miscellaneous Points

13.2. Amplifier Grounding

13.3. Ground Loops: How They Work and How to Deal with Them

13.3.1. Hum Injection by Mains Grounding Currents

13.3.2. Hum Injection by Transformer Stray Magnetic Fields

13.3.3. Hum Injection by Transformer Stray Capacitance

13.3.4. Ground Currents Inside Equipment

13.3.5. Balanced Mains Power

13.4. Class I and Class II

13.4.1. Warning

13.5. Mechanical Layout and Design Considerations

13.5.1. Cooling

13.5.2. Convection Cooling

13.5.3. Mains Transformers

13.5.4. Wiring Layout

13.5.5. Semiconductor Installation

IV. Digital Audio

Chapter 14. Digital Audio Fundamentals

14.1. Audio as Data

14.2. What is an Audio Signal?

14.3. Why Binary?

14.4. Why Digital?

14.5. Some Digital Audio Processes Outlined

14.6. Time Compression and Expansion

14.7. Error Correction and Concealment

14.8. Channel Coding

14.9. Audio Compression

14.10. Disk-Based Recording

14.11. Rotary Head Digital Recorders

14.12. Digital Audio Broadcasting

14.13. Networks

Chapter 15. Representation of Audio Signals

15.1. Introduction

15.2. Analogue and Digital

15.3. Elementary Logical Processes

15.4. The Significance of Bits and Bobs

15.5. Transmitting Digital Signals

15.6. The Analogue Audio Waveform

15.7. Arithmetic

15.8. Digital Filtering

15.9. Other Binary Operations

15.10. Sampling and Quantizing

15.10.1. Sampling

15.10.2. Quantizing

15.10.3. Other Forms of ADC and DAC

15.11. Transform and Masking Coders

References

Chapter 16. Compact Disc

16.1. Problems with Digital Encoding

16.1.1. Quantization Noise

16.1.2. Bandwidth

16.1.3. Translation Nonlinearity

16.1.4. Detection and Correction of Transmission Errors

16.1.5. Filtering for Bandwidth Limitation and Signal Recovery

16.2. The Record-Replay System

16.2.1. The Recording System Layout

16.2.2. Disc Recording

16.3. The Replay System

16.3.1. Physical Characteristics

16.3.2. Electronic Characteristics

16.4. Error Correction

16.4.1. Error Detection

16.4.2. Faulty Bit/Word Replacement

Chapter 17. Digital Audio Recording Basics

17.1. Types of Media

17.1.1. Magnetic Recording

17.1.2. Optical Discs

17.1.3. Magneto-Optical Discs

17.2. Recording Media Compared

17.3. Some Digital Audio Processes Outlined

17.3.1. The Sampler

17.3.2. The Programmable Delay

17.3.3. Time Compression

17.3.4. Synchronization

17.3.5. Error Correction and Concealment

17.3.6. Channel Coding

17.4. Hard Disc Recorders

17.5. The PCM Adaptor

17.6. An Open Reel Digital Recorder

17.7. Rotary Head Digital Recorders

17.8. Digital Compact Cassette

17.9. Editing Digital Audio Tape

Uncited Reference

Chapter 18. Digital Audio Interfaces

18.1. Digital Audio Interfaces

18.1.1. AES/EBU or IEC958 Type 1 Interface

18.1.2. The SPDIF or IEC985 Type 2 Interface

18.1.3. Data

18.1.4. Practical Digital Audio Interface

18.1.5. TOSlink Optical Interface

18.1.6. Transmission of AES3-Formatted Data by Unbalanced Coaxial Cable

18.2. MADI (AES10–1991) Serial Multichannel Audio Digital Interface

18.2.1. Data Format

18.2.2. Scrambling and Synchronization

18.2.3. Electrical Format

18.2.4. Fiber-Optic Format

Chapter 19. Data Compression

19.1. Lossless Compression

19.2. Intermediate Compression Systems

19.2.1. NICAM

19.3. Psychoacoustic Masking Systems

19.4. MPEG Layer 1 Compression (PASC)

19.4.1. Intensity Stereo Coding

19.4.2. The Discrete Cosine Transform

19.5. MPEG Layer 2 Audio Coding (MUSICAM)

19.6. MPEG Layer 3

19.6.1. Dolby AC-3

19.6.2. Dolby E

19.6.3. DTS

19.6.4. MPEG AAC

19.7. MPEG-4

19.7.1. Structured Audio

19.7.2. SAOL

19.7.3. Audio Scenes

19.8. Digital Audio Production

Chapter 20. Digital Audio Production

20.1. Digital Audio Workstations (DAWs)

20.1.1. Hard-Disk Editing

20.1.2. Low-Cost Audio Editing

20.1.3. Professional Audio Editing

20.1.4. Multitrack Hard-Disk Recording

20.1.5. Plug-ins

20.2. Audio Data Files

20.2.1. Wav Files

20.2.2. AU Files

20.2.3. AIFF and AIFC

20.2.4. MPEG

20.2.5. VOC

20.2.6. Raw PCM Data

20.3. Sound Cards

20.4. PCI Bus Versus ISA Bus

20.5. Disks and Other Peripheral Hardware

20.6. Hard Drive Interface Standards

20.6.1. IDE Drives

20.6.2. SCSI

20.6.3. Fiber Channel

20.6.4. Firewire (IEEE 1394) Interface

20.7. Digital Noise Generation—Chain Code Generators

Uncited Reference

Chapter 21. Other Digital Audio Devices

21.1. Video Recorders

21.2. High Definition Compatible Digital (HDCD)

21.3. CD Writers

21.3.1. Uses

21.4. MPEG Systems

21.4.1. Layers

21.5. MP3

21.6. Transcribing a Recording by Computer

21.7. WAV Onward

21.8. DAM CD

21.9. DVD and Audio

21.9.1. Regionalization

21.9.2. Copy Protection

21.9.3. DVD-Audio

V. Microphone and Loudspeaker Technology

Chapter 22. Microphone Technology

22.1. Microphone Sensitivity

22.2. Microphone Selection

22.2.1. Carbon

22.2.2. Capacitor

22.2.3. Moving Coil

22.2.4. Ribbon

22.2.5. Piezoelectric

22.2.6. Matching Talker to Microphone

22.3. Nature of Response and Directional Characteristics

22.4. Wireless Microphones

22.5. Microphone Connectors, Cables, and Phantom Power

22.6. Measurement Microphones

22.6.1. Measurement Microphone Types

Further Reading

Chapter 23. Loudspeakers

23.1. Radiation of Sound

23.2. Characteristic Impedance

23.3. Radiation Impedance

23.4. Radiation from a Piston

23.5. Directivity

23.6. Sound Pressure Produced at Distance r

23.7. Electrical Analogue

23.8. Diaphragm/Suspension Assembly

23.9. Diaphragm Size

23.10. Diaphragm Profile

23.11. Straight-Sided Cones

23.12. Material

23.13. Soft Domes

23.14. Suspensions

23.15. Voice Coil

23.16. Moving Coil Loudspeaker

23.17. Motional Impedance

23.17.1. Analogue Models

Uncited Reference

Chapter 24. Loudspeaker Enclosures

24.1. Loudspeakers

24.1.1. Loudspeaker Drive-Unit Basics

24.1.2. Loudspeaker Sensitivity versus Efficiency

24.1.3. Loudspeaker Enclosure Types and Efficiencies

24.1.4. Loudspeaker Configurations: A Résumé

24.2. The Interrelation of Components

24.2.1. What Loudspeakers Look Like to the Amplifier

24.2.2. What Speakers Are Looking For

24.2.3. What Passive Crossovers Look Like to Amplifiers

Chapter 25. Headphones

25.1. A Brief History

25.2. Pros and Cons of Headphone Listening

25.2.1. Dummy Heads

25.2.2. Cross-Blending

25.2.3. Biphonics

25.3. Headphone Types

25.3.1. Moving Iron

25.3.2. Moving Coil

25.3.3. Electrodynamics Orthodynamic

25.3.4. Electrostatic

25.3.5. Electrets

25.3.6. High Polymer

25.4. Basic Headphone Types

25.4.1. Velocity

25.4.2. Pressure

25.4.3. Intra-Aural

25.5. Measuring Headphones

25.6. The Future

VI. Sound Reproduction Systems

Chapter 26. Tape Recording

26.1. Introduction

26.2. Magnetic Theory

26.3. The Physics of Magnetic Recording

26.4. Bias

26.5. Equalization

26.6. Tape Speed

26.7. Speed Stability

26.8. Recording Formats—Analogue Machines

26.8.1. Analogue Mastering

26.8.2. Analogue Multitrack Tape Machines

26.8.3. Cassette-Based Multitracks

Chapter 27. Recording Consoles

27.1. Introduction

27.2. Standard Levels and Level Meters

27.2.1. The VU Meter

27.2.2. The PPM Meter

27.2.3. PPM Dynamic Performance

27.2.4. Opto-electronic Level Indication

27.2.5. Polar CRT Displays

27.3. Standard Operating Levels and Line-Up Tones

27.4. Digital Line-Up

27.5. Sound Mixer Architecture and Circuit Blocks

27.5.1. System Architecture

27.5.2. Input Strip

27.5.3. Groups

27.5.4. Pan Control

27.5.5. Effect Sends and Returns

27.5.6. The Groups Revisited

27.5.7. The Recording Console

27.5.8. Talkback

27.5.9. Equalizers

27.6. Audio Mixer Circuitry

27.6.1. Microphone Preamplifiers

27.6.2. Insert Points

27.6.3. Equalizers and Tone Controls

27.6.4. Inductor–Gyrators

27.6.5. ‘Q’

27.6.6. Effect Send and Return

27.6.7. Faders and Pan Controls

27.6.8. Mix Amplifiers

27.6.9. Line-Level Stages

27.7. Mixer Automation

27.7.1. Time Code

27.8. Digital Consoles

27.8.1. Introduction to Digital Signal Processing (DSP)

27.8.2. Digital Manipulation

27.8.3. Digital Filtering

27.8.4. Digital Mixer Architecture

Reference

Chapter 28. Video Synchronization

28.1. Introduction

28.2. Persistence of Vision

28.3. Cathode Ray Tube and Raster Scanning

28.4. Television Signal

28.4.1. Horizontal and Vertical Sync

28.5. Color Perception

28.6. Color Television

28.6.1. NTSC and PAL Color Systems

28.7. Analogue Video Interfaces

28.8. Digital Video

28.8.1. The 4:2:2 Protocol Description—General

28.8.2. Parallel Digital Interface

28.8.3. Serial Digital Video Interface

28.9. Embedded Digital Audio in the Digital Video Interface

28.10. Time Code

28.10.1. Longitudinal Time Code (LTC)

28.10.2. Vertical Interval Time Code (VITC)

28.10.3. PAL and NTSC

28.10.4. User Bits

Chapter 29. Room Acoustics

29.1. Introduction

29.2. Noise Control

29.2.1. External Airborne Noise

29.2.2. Internally and Locally Generated Noise

29.2.3. Internal Noise Transfer

29.2.4. Sound Insulation

29.3. Studio and Control Room Acoustics

29.3.1. Absorbers

29.3.2. Resonances

29.3.3. Absorber Performance

29.3.4. Reverberation and Reflection

VII. Audio Test and Measurement

Chapter 30. Fundamentals and Instruments

30.1. Instrument Types

30.2. Signal Generators

30.2.1. Sinewave Oscillators

30.2.2. Digital Waveform Generation

30.3. Alternative Waveform Types

30.4. Distortion Measurement