The Audio Expert: Everything You Need to Know about Audio

Description

The Audio Expert is a comprehensive reference book covering all aspects of audio, with both practical and theoretical explanations. It is written for people who want to understand audio at the deepest, most technical level, but without needing an engineering degree. The Audio Expert explains how audio really works in much more depth than usual, using common sense plain-English explanations and mechanical analogies, with minimal math. It uses an easy to read conversational tone, and includes more than 400 figures and photos to augment the printed text. However, this book goes beyond merely explaining how audio works. It brings together the concepts of audio, aural perception, musical instrument physics, acoustics, and basic electronics, showing how they’re intimately related. It also describes in great detail many practices and techniques used by recording and mixing engineers, including video production and computers. This book is meant for intermediate to advanced recording engineers and audiophiles who want to become experts. There’s plenty for beginners too. One unique feature is explaining how audio devices such as equalizers, compressors, and A/D converters work internally, and how they’re spec’d and tested, rather than merely describing how to use them. There’s plenty of myth-busting and consumerism too. The book doesn’t tell readers what brand power amplifier to buy, but it explains in great detail what defines a good amplifier so people can choose a first-rate model wisely without over-paying. Most explanations throughout the book are platform-agnostic, applying equally to Windows and Mac computers, and to most software and hardware. Many audio and video examples are included to enhance the written text. The new edition offers many updates and improvements throughout. New sections on coding an equalizer, comparing microphone preamps, testing results of loudspeaker isolation devices, new online video content on music theory, plus incorporated chapters on MIDI basics, computers, video production, plus new myth-busters, and much more! Cover......Page 1 Title......Page 4 Copyright......Page 5 Dedication......Page 6 Contents......Page 7 Acknowledgments......Page 22 About the Author......Page 24 Introduction......Page 26 Bonus Web Content......Page 28 Part 1 Audio Defined......Page 29 Volume and Decibels......Page 30 Standard Signal Levels......Page 33 Signal Levels and Metering......Page 37 Calculating Decibels......Page 39 Frequencies......Page 40 Standard Octave and Third-Octave Bands......Page 42 Filters......Page 43 Phase Shift and Time Delay......Page 49 Comb Filtering......Page 55 Fourier and the Fast Fourier Transform......Page 62 Sine Waves, Square Waves, and Pink Noise—Oh My!......Page 64 Resonance......Page 72 Audio Terminology......Page 76 The Null Test......Page 78 Summary......Page 79 High Fidelity Defined......Page 81 The Four Parameters......Page 83 Lies, Damn Lies, and Audio Gear Specs......Page 88 Test Equipment......Page 90 Audio Transparency......Page 97 Common Audio Myths......Page 98 The Stacking Myth......Page 103 Myth-Information......Page 108 The Big Picture......Page 109 Summary......Page 110 Chapter 3: Hearing, Perception, and Artifact Audibility......Page 112 Fletcher-Munson and the Masking Effect......Page 116 Distortion and Noise......Page 119 Jitter......Page 120 Audibility Testing......Page 122 Dither and Truncation Distortion......Page 125 Hearing Below the Noise Floor......Page 126 Frequency Response Changes......Page 127 Ultrasonics......Page 130 Ringing......Page 133 Aliasing......Page 137 Phase Shift......Page 138 Absolute Polarity......Page 139 Ears Are Not Linear!......Page 141 Blind Testing......Page 143 Calibrate the Preamp Gain Controls......Page 147 Prepare and Play the Tracks......Page 148 Psychoacoustic Effects......Page 149 Placebo Effect and Expectation Bias......Page 152 When Subjectivists Are (Almost) Correct......Page 155 Summary......Page 164 Audio Signals......Page 167 Audio Wiring......Page 170 Audio Connectors......Page 177 Patch Panels......Page 186 Impedance......Page 191 Summary......Page 196 Part 2 Analog and Digital Recording, Processing, and Methods......Page 198 Chapter 5: Mixers, Buses, Routing, and Summing......Page 200 Solo, Mute, and Channel Routing......Page 204 Buses and Routing......Page 206 Console Automation......Page 208 Other Console Features......Page 210 Digital Audio Workstation Software and Mixing......Page 212 The Pan Law......Page 216 Connecting a Digital Audio Workstation to a Mixer......Page 217 Inputs and Outputs......Page 218 Setting Record Levels......Page 222 Monitoring with Effects......Page 223 The Windows Mixer......Page 225 Related Digital Audio Workstation Advice......Page 228 5.1 Surround Sound Basics......Page 229 Summing......Page 235 Gain Staging......Page 238 Microphone Preamplifiers......Page 239 Preamp Input Impedance......Page 240 Preamp Noise......Page 241 Clean and Flat Is Where It’s At......Page 243 Summary......Page 244 Recording Hardware......Page 246 Analog Tape Recording......Page 247 Tape Bias......Page 249 Tape Pre-Emphasis and De-Emphasis......Page 250 Sel-Sync......Page 251 Tape Noise Reduction......Page 252 The Failings of Analog Tape......Page 254 Digital Recording......Page 258 In the Box versus Out of the Box......Page 260 Record Levels......Page 261 The Myth of Low Levels......Page 263 Recording Methods......Page 265 Specific Advice on Digital Audio Workstations......Page 267 Copy Protection......Page 269 Microphone Types and Methods......Page 271 Micing Techniques......Page 273 The 3-to-1 Rule......Page 281 Microphone Placement......Page 283 DI = Direct Injection......Page 287 Additional Recording Considerations......Page 289 Advanced Recording Techniques......Page 293 Vari-Speed......Page 294 Summary......Page 296 Chapter 7: Mixing Devices and Methods......Page 299 Volume Automation......Page 300 Editing......Page 301 Basic Music Mixing Strategies......Page 303 Be Organized......Page 304 Reference Mixes......Page 305 Panning......Page 306 Avoid Too Much Reverb......Page 308 Thin Your Tracks......Page 309 Bus versus Insert......Page 310 Pre and Post, Mute and Solo......Page 311 Perception Is Fleeting......Page 312 Be Creative!......Page 313 In the Box versus Out of the Box—Yes, Again......Page 315 Using Digital Audio Workstation Software......Page 316 Slip-Editing and Cross-Fading......Page 321 Track Lanes......Page 322 Editing and Comping......Page 323 Who’s on First?......Page 325 Time Alignment......Page 327 Editing Music......Page 328 Editing Narration......Page 329 Re-Amping......Page 331 Backward Audio......Page 332 Mastering......Page 333 Save Your Butt......Page 334 Summary......Page 335 Sampling Theory......Page 338 Quantization......Page 340 Sample Rate and Bit Depth......Page 341 The Reconstruction Filter......Page 342 Bit Depth......Page 345 Pulse-Code Modulation versus Direct Stream Digital......Page 346 Digital Notation......Page 347 Sample Rate and Bit Depth Conversion......Page 350 Dither and Jitter......Page 352 External Clocks......Page 353 Digital Converter Internals......Page 354 Bit-Rate......Page 358 Latency......Page 360 Floating Point Math......Page 362 Early Digital......Page 366 Digital Audio Quality......Page 367 Digital Timing......Page 368 Summary......Page 369 Compressors and Limiters......Page 371 Using a Compressor......Page 375 Common Pitfalls......Page 376 Multi-band Compressors......Page 377 Noise Gates and Expanders......Page 379 Expanders......Page 382 But …......Page 383 Dynamics Processor Special Techniques......Page 384 Other Dynamics Processors......Page 386 Compressor Internals......Page 389 Time Constants......Page 391 Summary......Page 395 Equalizer Types......Page 397 All Equalizers (Should) Sound the Same......Page 403 Digital Equalizers......Page 404 EQ Techniques......Page 405 Boosting versus Cutting......Page 407 Common EQ Frequencies......Page 409 Mixes That Sound Great Loud......Page 411 Complementary EQ......Page 412 Mid/Side Equalization......Page 413 Extreme EQ......Page 414 Linear Phase Equalizers......Page 415 Equalizer Internals......Page 417 Other Frequency Processors......Page 419 Summary......Page 424 Echo......Page 427 Reverb......Page 431 Phasers and Flangers......Page 442 Summary......Page 445 Pitch Shifting Basics......Page 447 Auto-Tune and Melodyne......Page 453 Acidized Wave Files......Page 454 Summary......Page 455 Tape-Sims and Amp-Sims......Page 457 Software Noise Reduction......Page 460 Other Processors......Page 464 Vocal Removal......Page 465 Ring Modulators......Page 466 Summary......Page 468 Chapter 14: Synthesizers......Page 469 Analog versus Digital Synthesizers......Page 470 Additive versus Subtractive Synthesis......Page 471 Voltage Control......Page 474 Sound Generators......Page 475 Modulators......Page 476 Filters......Page 479 MIDI Keyboards......Page 480 Beyond Presets......Page 481 Alternate Controllers......Page 486 Samplers......Page 489 Software Synthesizers and Samplers......Page 493 Sample Libraries......Page 494 Creating Sample Libraries......Page 496 Key and Velocity Switching......Page 498 Sampler Bank Architecture......Page 500 FM Synthesis......Page 503 Physical Modeling......Page 506 Prerendering......Page 507 Algorithmic Composition......Page 508 Notation Software......Page 510 Summary......Page 512 MIDI Internal Details......Page 514 MIDI Hardware......Page 515 MIDI Channels and Data......Page 516 MIDI Data Transmission......Page 518 General MIDI......Page 519 Standard MIDI Files......Page 524 MIDI Clock Resolution......Page 525 MIDI Minutiae......Page 527 Playing and Editing MIDI......Page 528 Summary......Page 531 Part 3 Video Production......Page 533 Video Production Basics......Page 535 Live Concert Example......Page 538 Color Correction......Page 540 Synchronizing Video to Audio......Page 542 Panning and Zooming......Page 544 Video Transitions......Page 545 Key Frames......Page 548 Orchestra Example......Page 550 Cello Rondo and Tele-Vision Examples......Page 551 Backgrounds......Page 553 Time-Lapse Video......Page 554 Media File Formats......Page 555 Lighting......Page 557 Summary......Page 558 Part 4 Transducers......Page 560 Chapter 17: Microphones and Pickups......Page 562 Microphone Types......Page 563 Dynamic Microphones......Page 565 Dynamic Directional Patterns......Page 568 Ribbon Microphones......Page 573 Condenser Microphones......Page 577 Condenser Directional Patterns......Page 582 Other Microphone Types......Page 583 Phantom Power......Page 585 Microphone Specs......Page 587 Measuring Microphone Response......Page 588 Microphone Modeling......Page 591 Guitar Pickups and Vibrating Strings......Page 592 Summary......Page 594 Chapter 18: Loudspeakers and Earphones......Page 596 Loudspeaker Basics......Page 597 Loudspeaker Driver Types......Page 600 Loudspeaker Enclosure Types......Page 606 Subwoofers......Page 616 Enclosure Refinements......Page 619 Crossovers......Page 620 Active versus Passive Speakers......Page 624 Room Acoustics Considerations......Page 625 Loudspeaker Impedance......Page 627 Loudspeaker Isolation......Page 631 Loudspeaker Polarity......Page 642 Earphones......Page 643 Loudspeaker Specs......Page 644 Accurate or Pleasing?......Page 652 House Curves......Page 657 Summary......Page 660 Part 5 Room Acoustics, Treatment, and Monitoring......Page 662 Chapter 19: Acoustic Basics......Page 664 Room Orientation and Speaker Placement......Page 666 Symmetry......Page 671 Reflection Points......Page 672 Won’t All That Absorption Make My Room Sound Dead?......Page 682 Calculating Reflection Points......Page 684 Angling the Walls and Ceiling......Page 687 Low-Frequency Problems......Page 689 Reverb Decay Time......Page 692 Stereo Monitoring......Page 693 Surround Monitoring......Page 699 SPL Meters......Page 700 Summary......Page 708 Chapter 20: Room Shapes, Modes, and Isolation......Page 711 Modal Distribution......Page 713 Room Ratios......Page 714 Modes, Nodes, and Standing Waves......Page 717 ModeCalc Program......Page 718 Room Anomalies......Page 721 Odd Room Layouts......Page 724 One Room versus Two Rooms......Page 727 Vocal Booths......Page 728 Surface Reflectivity......Page 731 Calculating Reflections......Page 733 Isolation and Noise Control......Page 734 Air Leaks......Page 740 Room within a Room......Page 741 Summary......Page 744 Acoustic Treatment Overview......Page 747 Buy or Build?......Page 749 Flutter Echo......Page 750 Absorb or Diffuse?......Page 752 Rigid Fiberglass......Page 753 Absorption Specs......Page 754 Material Thickness and Density......Page 756 Acoustic Fabric......Page 759 Wave Velocity, Pressure, and Air Gaps......Page 760 Bass Traps......Page 763 DIY Bass Traps......Page 765 Free Bass Traps!......Page 773 Diffusers......Page 778 Treating Listening Rooms and Home Theaters......Page 783 Bass in the Place......Page 788 Front Wall Absorption......Page 790 Treating Live Recording Rooms......Page 792 Hard Floor, Soft Ceiling......Page 794 Variable Acoustics......Page 796 Treating Odd Shaped Rooms......Page 797 Treating Large Venues......Page 799 Room Equalization......Page 802 Summary......Page 810 Why We Measure......Page 813 How We Measure......Page 814 Room Measuring Software......Page 817 Configuring Room EQ Wizard......Page 818 Using Room EQ Wizard......Page 820 Interpreting the Data......Page 822 Waterfall Plots......Page 824 RT60 Reverb Time......Page 825 Energy Time Curve......Page 826 Using the Real Time Analyzer......Page 828 Measuring Microphones......Page 829 Microphones Comparison......Page 830 The Results......Page 834 Calibrating Loudspeakers......Page 837 Summary......Page 838 Part 6 Electronics and Computers......Page 840 Ground......Page 844 Volts, Amps, Watts, and Ohms......Page 847 Electronic Components......Page 849 Capacitor Upgrades......Page 853 Inductors......Page 854 Power Ratings......Page 856 Solenoids......Page 857 Transformers......Page 859 Acoustic Impedance......Page 865 Switches......Page 866 Diodes......Page 867 Parasitic Elements......Page 871 Active Solid-State Devices......Page 873 Amplifier Damping......Page 876 Negative Feedback......Page 877 Power Supplies......Page 879 Passive Filters......Page 880 Amplifiers......Page 881 Slew Rate......Page 885 Understanding Op-Amps......Page 889 Negative Feedback......Page 891 Op-Amp Circuits with Gain......Page 894 Active Filters......Page 897 Digital Logic......Page 899 Wiring......Page 903 Practical Electronics......Page 906 Splitters and Pads......Page 908 Phone Patch......Page 910 Schematics and PC Boards......Page 911 Summary......Page 916 Chapter 24: Test Procedures......Page 918 Frequency Response......Page 920 Ringing......Page 921 IM Distortion......Page 923 Null Tests......Page 927 Oscilloscopes......Page 931 Summary......Page 936 Chapter 25: Computers......Page 938 Divide and Conquer......Page 939 Back Up Your Data......Page 943 Optimizing Performance......Page 945 Practice Safe Computing......Page 947 If It Ain’t Broke, Don’t Fix It......Page 948 Avoid Email Viruses......Page 949 Bits ’n’ Bytes......Page 950 Computer Programming......Page 952 Coding an Equalizer......Page 954 Website Programming......Page 960 Image Files......Page 962 Embedded Audio and Video......Page 963 Summary......Page 965 Part 7 Musical Instruments......Page 967 Chapter 26: Musical Instruments......Page 968 Instrument Types......Page 970 Sympathetic Resonance......Page 973 The Harmonic Series Is Out of Tune......Page 974 Equal Temperament......Page 976 “Wood Box” Instruments......Page 978 Bowed Instruments......Page 979 The Bow......Page 984 The Stradivarius......Page 985 Plucked Instruments......Page 986 Solid Body Electric Guitars......Page 988 Blown Instruments......Page 990 Flutes......Page 992 Single Reeds......Page 993 Double Reeds......Page 994 Brass Instruments......Page 995 Percussion Instruments......Page 997 The Piano......Page 1000 Summary......Page 1003 Index......Page 1006