Sound Reinforcement for Audio Engineers

__Sound Reinforcement for Audio Engineers__ illustrates the current state of the art in sound reinforcement. Beginning with an outline of various fields of applications, from sports venues to religious venues, corporate environments and cinemas, this book is split into 11 chapters covering room acoustics, loudspeakers, microphones and acoustic modelling among many other topics. This comprehensive book packed with references and a historical overview of sound reinforcement design is an essential reference book for students of acoustics and electrical engineering, but also for engineers looking to expand their knowledge of designing sound reinforcement systems. Cover Half Title Title Page Copyright Page Table of Contents Figures Tables Contributors 1 Introduction to Considered Sound Systems 1.1 Categories of Sound Systems 1.2 Public Buildings 1.2.1 Paging Systems 1.2.2 Voice Alarm Systems 1.2.3 Shopping Malls 1.2.4 Transportation Hubs 1.2.5 Hotels 1.2.6 Museums and Exhibition Halls 1.3 Sports Venues 1.3.1 Stadia 1.3.2 Arenas 1.3.3 Outdoor Fields/Campuses 1.4 Performing Arts Centres 1.4.1 Clubs / Discotheques 1.4.2 Music Venues 1.4.3 Theatres, Opera Houses and Concert Halls 1.4.4 Multipurpose Halls 1.5 Religious Venues 1.5.1 Churches, Synagogues and Mosques 1.6 Media Production Facilities 1.6.1 Audio Recording Studios and Broadcasting Facilities 1.7 Cinemas 1.7.1 THX, Dolby, DTS 1.7.2 Immersive Audio 1.7.3 Home Cinemas 1.8 Corporate Environments 1.8.1 Meeting Rooms / Boardrooms 1.8.2 Video Conferencing 1.9 Educational Facilities 1.9.1 Schools, Campuses 1.9.2 Classrooms References 2 Room Acoustics and Sound System Design 2.1 Developments in Acoustics 2.2 Interaction of Space, Room Acoustics and Sound Systems 2.2.1 General Issues 2.2.2 Room Acoustics Fundamentals 2.2.3 Assessment of the Quality of Sound Events 2.2.4 Objective Influencing Quantities, Criteria and Quality Parameters in Rooms 2.2.4.1 Reverberation Time, Critical Distance 2.2.4.2 Analysis of the Energy-Time Curve 2.2.4.3 Criteria for Speech Intelligibility and Clarity for Music 2.3 Basics in Sound Propagation 2.3.1 Sound Propagation in the Open Air 2.3.2 Loudness Perception and Masking Effect 2.3.3 Echo Behaviour of the Auditory System 2.3.4 Acoustic Localization 2.4 Development of and Requirements for a Sound Reinforcement System 2.5 Integration of the Sound Reinforcement System in the Architectural Design 2.6 Acoustic Feedback 2.6.1 Mathematical and Physical Basics 2.6.1.1 General Information 2.6.1.2 Feedback in a Free Sound Field 2.6.1.3 Feedback in Closed Rooms 2.6.2 Feedback Calculation 2.7 Sound System and Reverberation Enhancement Systems 2.7.1 Use of Sound Systems 2.7.2 Electronic Procedures for Enhancing Reverberation and Spaciousness 2.8 Further Aspects Concerning the Use of Sound Reinforcement Systems References 3 Loudspeakers 3.1 Loudspeaker Types and Characteristics 3.1.1 The Principal Operation and Construction of the Dynamic Transducer 3.1.2 Complex Loudspeaker Systems 3.1.2.1 Loudspeaker Systems Modelled as Point Source 3.1.2.2 Loudspeaker Systems Described as Arrays of Point Sources 3.2 Output-Based Characterization of Point Source Loudspeaker Systems 3.2.1 Linear Dynamic Behaviour 3.2.1.1 Frequency Domain Description: The Frequency Response Curves (Sensitivity, Impedance, Group Delay) 3.2.1.2 Time Domain Description: Impulse Response, Step Response, Waterfalls 3.2.2 Distortion 3.2.3 The Directional Characteristics 3.2.3.1 Display of Loudspeaker Directivities 3.2.3.2 The Directivity Index and Other Measures Related to Directivity 3.2.3.3 Loudspeaker Efficiency 3.2.4 Power Handling 3.3 Directional Loudspeakers 3.3.1 The Directivity of the Circular Piston 3.3.2 Horn-Loaded Loudspeaker Systems 3.3.2.1 Constant Directivity (CD) Horns 3.3.3 The Directivity of Multiple Sources 3.3.3.1 The Most Common Two-Way Loudspeaker System 3.3.4 Directivity Control Using Line Arrays 3.3.4.1 Straight Line Array With Identical Sources 3.3.5 More Complex Control of the Desired Directivity 3.3.5.1 DSP-Controlled Line Array Loudspeaker 3.3.5.2 Large Line Arrays 3.3.5.3 Two-Dimensional Arrays References 4 Microphones 4.1 The Different Transducer Types for Microphones 4.1.1 The Condenser Microphone 4.1.1.1 The Dynamic Microphone 4.1.2 Differentiation of the Application 4.2 Microphones and Application 4.2.1 Characterization of Microphone Parameters 4.2.1.1 Type of Microphone and Related Directivity Pattern 4.2.1.2 Interconnecting Microphones and Preamps 4.2.1.3 Microphone Sensitivity, Signal To-Noise Ratio, Maximum SPL 4.2.1.4 Directional Behaviour of Microphones 4.2.1.5 Application-Related Microphone Characterization References 5 Design for Sound Reinforcement Systems 5.1 Introduction 5.2 Sound Pressure Level and Signal To-Noise Ratio 5.3 Transfer Function, Impulse Response, Frequency Response 5.4 Important Design Criteria for Sound Systems 5.4.1 Loudspeaker Coverage and Off-Axis Sound Radiation 5.4.1.1 Introduction 5.4.1.2 Coverage Issues 5.4.2 Delay Issues, Time Alignment, Equalization and Gain Before Feedback 5.4.2.1 Travel Time Phenomena 5.4.2.2 Suppression of Echoes 5.4.2.3 Feedback Suppressor 5.4.2.4 Use of Narrow Band Filters 5.4.2.5 Frequency Shifter 5.4.3 Equalization By Filtering 5.5 Basic Tools and Parameters for Computer-Based Calculation 5.5.1 Practical Use of Computer-Based Simulation 5.5.1.1 Room Acoustic Simulation 5.5.1.2 Results of All These Calculations 5.5.2 Sound System Design By Verification of Simulation Results 5.5.2.1 Aiming 5.5.2.2 Time-Arrivals, Delay, Alignment 5.5.2.3 SPL Calculations 5.5.2.4 Mapping and Single-Point Investigations 5.5.3 Auralization 5.6 Efficiency – Costs, Space, Weight References 6 System Design Approaches 6.1 Introduction 6.2 Important Acoustic Parameters for Sound Design 6.2.1 Sound Level Calculation 6.2.1.1 Free Field (Direct Field of the Loudspeaker) 6.2.1.2 Diffuse Field 6.2.1.3 Real Rooms 6.3 Layout of Sound Reinforcement Systems 6.3.1 Information Systems With Distributed Loudspeakers 6.3.1.1 Flat Rooms 6.3.1.2 Factory and Exhibition Halls 6.3.1.3 Complexes of Individual Rooms 6.3.1.4 Sound Coverage of Outdoor and Traffic Areas 6.3.2 Simple Sound Systems 6.3.2.1 Determination of the Acoustic Gain of a Simple Sound System 6.3.2.2 Simple Centralized Reinforcement System 6.3.3 Multi-Channel Systems With and Without Delay Units 6.3.4 Improving the Naturalness of Sound Reproduction 6.3.4.1 Arrangement of the Loudspeakers 6.3.4.2 Single-Channel Sound Delay 6.3.4.3 Multi-Channel Procedures With Delay Systems 6.3.5 Multipurpose Systems 6.3.6 Assistive Listening Systems (ALS) 6.3.6.1 Induction Loops 6.3.6.2 Infrared Transmission 6.3.6.3 FM Transmission Appendix 6.1 Details of the Acoustic Gain Calculation References 7 Speech Intelligibility of Sound Systems 7.1 Factors That Affect the Intelligibility of Sound Systems 7.2 Discussion of Intelligibility Factors and Implications for Successful System Design 7.2.1 Primary Factors 7.2.1.1 Sound System Bandwidth and Frequency Response 7.2.1.2 Absolute Sound Pressure Level (SPL) / Loudness 7.2.1.3 Signal To-Noise Ratio (SNR) 7.2.1.4 Reverberation Time (RT)+ 7.2.1.5 Volume, Floor Area and Shape of the Space+ 7.2.1.6 Distance Between Listener and Loudspeaker(s)+ 7.2.1.7 Directivity of Loudspeaker+ 7.2.1.8 Number of Loudspeakers Operating Simultaneously+ 7.2.2 Secondary Factors 7.2.2.1 Uniformity of Sound Coverage 7.2.2.2 Sound Focussing and Discrete (Late Arriving) Reflections 7.2.2.3 System Distortion (Including Headroom / Signal Clipping) 7.2.2.4 System Equalisation 7.2.2.5 Direction of Primary Sound Arrival 7.2.2.6 Direction of Interfering Noise (Particularly Relative to Source of Sound) 7.2.2.7 Talker Type – Male, Female and Accented 7.2.2.8 Vocabulary (Complexity) and Context of Speech Information 7.2.2.9 Talker Enunciation (Articulation) and Rate of Delivery 7.2.2.10 Talker / Listener First Language 7.2.2.11 Listener Acuity (Hearing Ability) 7.2.2.12 Talker Microphone Technique 7.2.2.13 SNR at Microphone 7.2.2.14 Visual Contact Between the Listener and Talker 7.2.2.15 Signal-Processing Effects (E.g. Compression, Automatic Gain Control (AGC), Limiting, Echo Cancellation, Latency) 7.2.2.16 Electronic Interference of Audio Signal (Hum, Noise, Signal Continuity / Interruption) 7.3 The Speech Signal and Implications for Intelligible Sound System Design 7.4 Speech Intelligibility Measures and Measurement 7.4.1 Brief Description of STI 7.4.2 STI Use and Limitations 7.4.3 Other and New Methods of Speech Intelligibility Assessment 7.4.3.1 Percentage Loss of Consonants (% ALcons) 7.4.3.2 Coherence 7.4.4 A Comment About System Frequency Response and Intelligibility 7.5 Summary of Sound System Design Factors Required for Good Intelligibility Notes References 8 Acoustic Modelling – Basics 8.1 Why to Model and What Modelling Can Do 8.2 Required Data for Simulation Models 8.2.1 Input Data for the Model 8.2.2 Loudspeaker Data 8.2.3 Wall Materials 8.2.3.1 Absorber Data 8.2.3.2 Scattering Data 8.2.3.3 Diffraction, Low-Frequency Absorption 8.3 Simulation Methods 8.3.1 Direct Field 8.3.2 Early Reflections 8.3.3 Reverberation 8.3.4 Room Modes 8.4 Numerical Optimization 8.5 Numerical Methods of Geometrical Acoustics 8.5.1 Image Source Method 8.5.2 Ray Tracing Based On Monte Carlo Methods 8.5.3 Derivatives and Tail Extensions 8.5.4 Wave-Based Extensions 8.5.5 Performance Considerations 8.5.6 Limitations 8.6 Model Data and Output 8.7 Modelling Reliability 8.7.1 Input Data 8.7.2 Model Calibration 8.7.3 Modelling Engine 8.7.4 Interpretation and Validation of Results 8.8 Auralization References 9 Audio Networking 9.1 Introduction 9.1.1 Advantages and Disadvantages of Using Audio-Over-IP 9.1.2 Phase Accuracy 9.1.3 General Requirements for Audio-Over-IP Connections 9.2 Connectivity 9.2.1 Network Terminology 9.2.2 IP Addresses and Subnet Masks 9.2.3 Network Topologies 9.2.3.1 Star 9.2.3.2 Ring 9.2.4 Unicast and Multicast 9.2.5 Quality of Service (QoS) Recommended QoS Settings 9.3 Synchronization 9.3.1 Selection of the PTP Leader 9.3.2 PTP Profiles - Recommended Settings 9.3.3 PTP Support in Switches 9.3.3.1 Recommendation 9.4 Connection Management 9.4.1 Device and Stream Discovery 9.4.1.1 Device Discovery 9.4.1.2 Stream Discovery 9.4.2 Setup of Senders and Receivers 9.4.3 Stream Formats 9.5 Latency 9.6 Standards 9.6.1 AES67 9.6.2 SMPTE ST 2110 9.6.3 NMOS 9.6.4 Internet Protocol Media Experience (IPMX) 9.6.5 AES70 9.6.6 SNMP 9.6.7 Milan (AVB/TSN) 9.7 Proprietary Technologies 9.7.1 Ember+ 9.7.2 Dante and AES67 9.7.2.1 Connectivity 9.7.2.2 Synchronization 9.7.2.3 Connection Management 9.8 Redundancy 9.8.1 Spanning Tree Protocol (STP) 9.8.2 Link Aggregation 9.8.3 Stream Redundancy 9.9 Common Mistakes in Audio Networks 9.9.1 Incorrect Device IP Settings 9.9.2 Incorrect Matrix Settings in Audio Devices 9.9.3 Occasional Audio Dropouts Or No Audio at All 9.9.4 Unexpected Traffic On the Network 9.9.5 Network Congestion Due to Lack of QoS 9.9.6 Unstable PTP Synchronization 9.9.7 Audio Problems On a Computer With a Virtual Sound Card 9.9.8 Stream Format Not Supported 9.9.9 The Switch Is Not Suitable for Audio Networks 9.9.10 Devices and Streams Not Visible References 10 Commissioning, Calibration, Optimization 10.1 Introduction 10.2 Functional Testing and Installation Verification 10.2.1 Electrical 10.2.2 Mechanical 10.2.3 Acoustical 10.3 Troubleshooting 10.4 Calibration and Optimization 10.4.1 Electrical 10.4.2 Mechanical 10.4.3 Acoustical 10.4.3.1 Room Acoustical Properties 10.4.3.2 Electro-Acoustical Properties 10.4.4 Subjective Evaluation 10.5 Documentation 10.5.1 Electrical 10.5.2 Mechanical 10.5.3 Acoustical 10.6 Acoustical Measurements 10.6.1 Measurement Methods 10.6.1.1 Traditional Sound Level Measurements 10.6.1.2 Current Sound Level Measurements 10.6.2 Measurement Techniques Based On Fourier Analysis 10.6.2.1 Fundamentals 10.6.2.2 Conventional Excitation Signals 10.6.2.3 Measurements With Frequency Sweeps 10.6.2.4 Measurements With Other Noise 10.6.2.5 Measurements With Maximum Length Sequences 10.6.2.6 TDS Method and Technique 10.6.2.7 Measurements Using Arbitrary Excitation Signals 10.7 Performing Acoustical Measurements 10.7.1 General Comments 10.7.2 Selection of Measurement Locations 10.7.3 Measurement of Room Acoustic Properties 10.7.4 Time Domain 10.7.5 Frequency Domain 10.7.6 Waterfall Diagram 10.7.7 Special Applications 10.7.7.1 Filtering and Averaging 10.7.7.2 Determining Timing of Sources 10.7.7.3 Signal Alignment 10.7.7.4 Acoustic Feedback 10.7.7.5 Polarity Test References 11 System Solutions / Case Studies 11.1 Paging and Voice Alarm Systems 11.1.1 Common Features and Differences 11.1.2 Target Room Acoustic Measures 11.1.3 Different System Layout Approaches as a Base for Computer Simulation 11.1.4 Verification With Different Measurement Tools 11.1.5 Case Studies 11.1.5.1 Airport – Hamad International Airport, Doha, Qatar 11.1.5.2 Railway Station – Main Station, Berlin, Germany 11.1.5.3 Multi-Storey Lobby – Elbphilharmonic Hall, Hamburg, Germany 11.2 Sports Facilities 11.2.1 Large Meeting Rooms Used for Sport Events and Smaller Sports Halls 11.2.2 Sports and Multipurpose Halls 11.2.3 Sports Stadia 11.2.3.1 Basic Requirements for Loudness and Sound Reinforcement in Stadia 11.2.3.2 Target Groups for Sound Radiation 11.2.3.3 Sound Coverage in Sports Stadia 11.2.4 Case Studies 11.2.4.1 Getec-Arena, Magdeburg, Germany 11.2.4.2 Stadium – Green Point Stadium, Cape Town, South Africa 11.3 Hotels, Museums, Exhibition Halls and Convention Centres 11.3.1 Common Features and Differences 11.3.2 Target Room Acoustic Measures 11.3.2.1 Different System Layout Approaches as a Base for Computer Simulation 11.3.3 Verification With Different Measurement Tools 11.3.4 Cases Studies 11.3.4.1 Museum – National Museum, Beijing China 11.3.4.2 Hotel – Lusail Hotel, Doha, Qatar 11.4 Theatres and Concert Halls 11.4.1 Common and Special Features of These Facilities 11.4.1.1 Single-Purpose Facilities 11.4.1.2 Repertoire and All-Purpose Theatre 11.4.1.3 Concerts in Multi-Purpose Halls for Modern Music 11.4.2 Task of Sound Systems in Theatres and Concert Halls 11.4.2.1 Tasks in General 11.4.2.2 Systems in Detail Explained in a Theatre 11.4.3 Target Criteria for Sound Systems 11.4.3.1 Intelligibility, Sound Level Coverage 11.4.3.2 Clarity and Spaciousness 11.4.4 Brief Summary of the Two Different System Layouts 11.4.4.1 Pure Sound System Design 11.4.4.2 Use of Additional Enhancement Systems 11.4.4.3 Measurement Approaches 11.4.5 Case Studies 11.4.5.1 Musical Theater – Musiktheater Linz, Austria 11.4.5.2 Concert Hall - Organ and Concert Hall Kharkov, Ukraine 11.5 Multipurpose Halls 11.5.1 Common and Special Features 11.5.2 Acoustics and Sound Systems 11.5.2.1 Target Measures 11.5.2.2 Different System Layout Approaches as a Base for Simulation 11.5.2.3 Measurement Approaches 11.5.3 Case Studies 11.5.3.1 Convention Centre – Congress Centrum Suhl, Germany 11.5.3.2 Pop/Rock Venue – The Anthem Hall, Washington DC, USA 11.6 Sacral Buildings 11.6.1 Buddhism 11.6.2 Judaism 11.6.2.1 Architectural, Acoustic and Sound Design 11.6.2.2 Case Studies 11.6.3 Christianity 11.6.3.1 Architectural Design 11.6.3.2 Acoustic Properties 11.6.3.3 Case Studies 11.6.4 Islam References Index "Sound Reinforcement for Audio Engineers illustrates the current state of the art in sound reinforcement. Beginning with an outline of various fields of applications, from sports venues to religious venues, corporate environments and cinemas, this book is split into twelve sections covering room acoustics, loudspeakers, microphones, and acoustic modelling among many other topics. Ending with a comprehensive appendix packed with references and a historical overview of sound reinforcement design, this is the essential reference book for both students of acoustics and electrical engineering, but also for engineers looking to expand their knowledge of designing sound reinforcement systems"-- Provided by publisher