Ebook: Electroacoustical Reference Data

The need for a general collection of electroacoustical reference and design data in graphical form has been felt by acousticians and engineers for some time. This type of data can otherwise only be found in a collection of handbooks. Therefore, it is the author's intention that this book serve as a single source for many electroacoustical reference and system design requirements. In form, the volume closely resembles Frank Massa's Acoustic Design Charts, a handy book dating from 1942 that has long been out of print. The basic format of Massa's book has been followed here: For each entry, graphical data are presented on the right page, while text, examples, and refer­ ences appear on the left page. In this manner, the user can solve a given problem without thumbing from one page to the next. All graphs and charts have been scaled for ease in data entry and reading. The book is divided into the following sections: A. General Acoustical Relationships. This section covers the behavior of sound transmis­ sion in reverberant and free fields, sound absorption and diffraction, and directional characteris­ tics of basic sound radiators. B. Loudspeakers. Loudspeakers are discussed in terms of basic relationships regarding cone excursion, sensitivity, efficiency, and directivity index, power ratings, and architectural layout. c. Microphones. The topics in this section include microphone sensitivity and noise rating, analysis of directional properties, stereo microphone array characteristics, proximity effects, and boundary conditions. D. Signal Transmission.

---

---

Content:
Front Matter....Pages i-ix
Front Matter....Pages 1-1
Sound Pressure and dB Lp (Sound Pressure Level)....Pages 2-3
Frequency and Wavelength in Air....Pages 4-5
Inverse Square Losses in a Free Field....Pages 6-7
Attenuation with Distance from Plane and Line Sources in a Free Field....Pages 8-9
Atmospheric Sound Absorption as a Function of Frequency and Relative Humidity, I....Pages 10-11
Atmospheric Sound Absorption as a Function of Frequency and Relative Humidity, II....Pages 12-13
Atmospheric Absorption Due to Inverse Square Losses and Relative Humidity....Pages 14-15
NC and PNC Noise Criteria Curves....Pages 16-17
Sound Transmission Class (STC) Curves....Pages 18-19
Helmholtz Resonators....Pages 20-21
Resonance Frequency for Pipes Open at Both Ends....Pages 22-23
End Correction for Pipes....Pages 24-25
Resonance Frequency for Pipes Open at One End....Pages 26-27
Diffraction of Sound by a Cylinder, a Cube, and a Sphere....Pages 28-29
Response Curves Showing Diffraction by 10 Objects of Different Shape....Pages 30-31
Fresnel Diffraction Over Sound Barriers....Pages 32-33
Definition of Critical Distance....Pages 34-35
Room Constant as a Function of Surface Area and Absorption....Pages 36-37
Reverberant Level as a Function of Room Constant and Acoustical Power....Pages 38-39
Front Matter....Pages 40-41
Mean Free Path (MFP), Room Volume, and Surface Area....Pages 1-1
Sound Attenuation over Distance in Semireverberant Spaces....Pages 42-43
Critical Distance as a Function of Room Constant and Directivity Factor....Pages 44-45
Acoustical Power Required to Produce a Level of 94 dB Lp as a Function of Room Volume and Reveberation Time....Pages 46-47
Sound Pressure Level Produced by 1 Acoustic Watt as a Function of Room Constant and Distance from Source....Pages 48-49
Estimation of Total Absorption When Room Volume and Reverberation Time are Known....Pages 50-51
Estimation of Room Constant When Room Volume and Reverberation Time are Known....Pages 52-53
Estimation of Room Boundary Area When Volume is Known....Pages 54-55
Reveberation Time Ratios with and Without Atmospheric Losses....Pages 56-57
Relationship Between Directivity Factor and Directivity Index....Pages 58-59
Wave Number (k) as a Function of Piston Size and Frequency....Pages 60-61
Polar Response of a Piston Mounted in a Large Baffle....Pages 62-63
Polar Response of a Piston Mounted at the End of a Long Tube....Pages 64-65
Polar Response of an Unbaffled Piston....Pages 66-67
Off-Axis Response of a Piston in a Large Baffle....Pages 68-69
Directivity of a Piston in a Large Baffle, at the End of a Long Tube, and in Free Space....Pages 70-71
Front Matter....Pages 72-73
Transmission Coefficient Versus Frequency for a Piston Mounted in a Large Baffle....Pages 75-75
Normalized Mutual Coupling for Multiple Pistons....Pages 76-77
Acoustical Power Output Produced on One Side of a Piston in a Large Baffle as a Function of Amplitude, Radius, and Frequency....Pages 78-79
Sound Pressure Level Produced by a Piston in a Large Baffle at a Distance of 1 Meter as a Function of Amplitude, Radius, and Frequency....Pages 80-81
Front Matter....Pages 82-83
Sound Pressure Level Produced by a Piston in a Large Baffle as a Function of Radiated Power and Distance....Pages 75-75
Peak Amplitude for 1 Acoustical Watt Radiated by a Piston into Half-Space as a Function of Radius and Frequency....Pages 84-85
Transducer Cone Deflection as a Function of Resonance Frequency....Pages 86-87
Second Harmonic Distortion in Horns....Pages 88-89
Frequency Modulation (FM) Distortion in Cone Transducers....Pages 90-91
Nominal Loudspeaker Efficiency as a Function of On-Axis Sensitivity and Directivity Index....Pages 92-93
Sensitivity Ratings for Loudspeaker Systems....Pages 94-95
Plane Wave Tube (PWT) Sensitivity Ratings for Compression Drivers....Pages 96-97
Radiation Resistance for Various Horn Flare Development Curves....Pages 98-99
High-Frequency Driver Electrical Derating for Flat Power Response Equalization....Pages 100-101
Duty Cycle-Related Power Ratings....Pages 102-103
Resistance Change with Temperature for Copper....Pages 104-105
Weighting Curves for Loudspeaker Power Measurements....Pages 106-107
House Equalization Standard Curves for Sound Reinforcement and Program Monitoring....Pages 108-109
Transducer Sensitivity as a Function of Atmospheric Pressure and Temperature....Pages 110-111
Relation Between 2? and 4? Loading and Baffle Size....Pages 112-113
Horn Mouth Size Versus ?6 dB Beamwidth Control....Pages 114-115
Beamwidth Control of Multicellular Horns....Pages 116-117
Beamwidth Narrowing with Vertical Stacked Horn Arrays....Pages 118-119
Directivity Versus Horizontal and Vertical Beamwidth....Pages 120-121
Front Matter....Pages 122-123
Beamwidth and Directivity Characteristics of a Pair of 250-mm (10-in) Low-Frequency Transducers....Pages 75-75
Beamwidth and Directivity Characteristics of a Pair of 300-mm (12-in) Low-Frequency Transducers....Pages 124-125
Beamwidth and Directivity Characteristics of a Pair of 380-mm (15-in) Low-Frequency Transducers....Pages 126-127
Distributed Loudspeaker Layout: Hexagonal Array....Pages 128-129
Distributed Loudspeaker Layout: Square Array....Pages 130-131
Dividing Networks: 6 dB per Octave Slopes....Pages 132-133
Dividing Networks: 12 dB Per Octave Slopes....Pages 134-135
Porting Data for Vented Loudspeaker Enclosures....Pages 136-137
Thiele-Small Parameters for Low-Frequency Horn Applications....Pages 138-139
Simple Line Arrays....Pages 140-141
Front Matter....Pages 142-143
Nomograph for Microphone Output Power and Voltage versus Microphone Impedance....Pages 145-145
Microphone Self-Noise Rating Curves....Pages 146-147
EIA GM Microphone Sensitivity Rating....Pages 148-149
First-Order Microphone Pattern Data....Pages 150-151
Mid-Side/XY Conversion Data....Pages 152-153
Random Energy Efficiency, Directivity Factor, and Distance Factor as a Function of Polar Pattern....Pages 154-155
Front-to-Total Ratio as a Function of Polar Pattern....Pages 156-157
Front-Back Ratio Versus Polar Pattern....Pages 158-159
Omni- and Bidirectional Components of the First-Order Cardioid Family....Pages 160-161
Back-to-Back Cardioid Components of the First-Order Cardioid Family....Pages 162-163
Front Matter....Pages 164-165
Splay Angles and Separation for Various Near-Coincident Stereo Microphone Arrays....Pages 145-145
Mid-Side (MS) and XY Microphone Pairs....Pages 166-167
Multipath and Multimicrophone Interference Effects....Pages 168-169
Effect of Dipole Dimension on Directional Microphone Frequency Response....Pages 170-171
Basic Proximity Effect in Directional Microphones....Pages 172-173
Proximity Effect in a Dipole Microphone at Several Distances....Pages 174-175
On-Axis Proximity Effect in a Cardioid Microphone at Several Distances....Pages 176-177
Proximity Effect in a Cardioid Microphone as a Function of Azimuth Angle....Pages 178-179
On-Axis and Diffuse Field Incidence Response of Omnidirectional Microphones....Pages 180-181
Delay Versus Level for Accent Microphones in Recording....Pages 182-183
Microphone Boundary Size Versus 2? to 4? Transition Frequency....Pages 184-185
Higher-Order Microphone Characteristics....Pages 186-187
Microphone Line Losses....Pages 188-189
Front Matter....Pages 190-191
Time Constant Versus Frequency....Pages 193-193
RIAA (Record Industry Association of America) Disc Pre-emphasis and De-emphasis....Pages 194-195
FM Broadcasting Pre-emphasis and De-emphasis....Pages 196-197
Early 78-rpm and 331/3-rpm Disc Pre-emphasis and De-emphasis Standards....Pages 198-199
Motion Picture Mono Optical Reproduce Standard....Pages 200-201
Digital Pre-emphasis and De-emphasis Standard....Pages 202-203
Comparison of Meters Used in Broadcasting and Recording....Pages 204-205
Front Matter....Pages 206-207
Power Ratios Expressed in dBm....Pages 193-193
Voltage Ratios Expressed in dBu....Pages 208-209
Power Ratios Expressed in dBW....Pages 210-211
Voltage Ratios Expressed in dBV....Pages 212-213
Sine Wave Voltage Output versus DC Voltage Capability....Pages 214-215
Resistance Values for Various Lengths and Gauges of Copper Wire....Pages 216-217
Metric Wire Gauges....Pages 218-219
High-Frequency Transducer Protection Capacitors....Pages 220-221
Design of Symmetrical T-pads....Pages 222-223
Design of L-pads....Pages 224-225
Summing of Levels....Pages 226-227
Distortion Percentage and Level....Pages 228-229
Load Impedance as a Function of Power Input in 70-Volt, 100-Volt, and 25-Volt Distribution Systems....Pages 230-231
Maximum Wire Runs for 0.5 dB Loss in 70-volt Systems....Pages 232-233
Peak and rms Values of Waveforms....Pages 234-235
Input and Output Impedances of Electronic Devices....Pages 236-237
Loudspeaker Damping Factor as a Function of Line Length and Wire Gauge....Pages 238-241
Amplifier Requirements: Direct Field Considerations....Pages 242-243
Amplifier Requirements: Reverberant Field Considerations....Pages 244-245
Panpot Response: One Channel to Two....Pages 246-247
Front Matter....Pages 248-249
Panpot Response: One Channel to Three....Pages 193-193
Quadraphonic Panpot Response: One Channel to Four....Pages 250-251
Effect of Noise on Speech Communication....Pages 252-253
Equivalent Acoustic Distance (EAD) and A-Weighted Noise Level....Pages 254-255
Horn Coverage Angle as Seen in Plan View....Pages 256-257
Peutz’s Percentage Articulation Loss of Consonants (Alcons)....Pages 258-259
Augspurger’s Modification of Peutz’s Data....Pages 260-261
Calculation of Articulation Index (AI)....Pages 262-263
Typical Motion Picture Screen Losses....Pages 264-265
House Equalization Standard for Motion Picture Systems....Pages 266-267
House Equalization for Motion Picture Systems: Adjustments for House Size....Pages 268-269
ISO (International Standards Organization) Preferred Numbers....Pages 270-271
Front Matter....Pages 272-273
Fletcher-Munson Equal Loudness Contours....Pages 275-275
Robinson-Dadson Equal Loudness Contours....Pages 276-277
Churcher-King Equal Loudness Contours....Pages 278-279
Determination of “Twice Loudness” at Low Frequencies....Pages 280-281
Calculation of Loudness in Sones....Pages 282-283
Standard Weighting Curves....Pages 284-285
Loudness and Signal Duration....Pages 286-287
Pitch and Level Relationships, I....Pages 288-289
Front Matter....Pages 290-291
Pitch and Level Relationships, I....Pages 275-275
Frequency and Pitch Relationships....Pages 292-293
Critical Bandwidth....Pages 294-295
Annoyance Due to Echo Effects....Pages 296-297
Blauert and Laws Criterion for the Audibility of Signal Group Delay....Pages 298-299
Optimum Reverberation Time as a Function of Room Volume and Usage....Pages 300-301
Optimum Reverberation Time as a Function of Frequency....Pages 302-303
Subjective Effects of First Reflections in a Concert Hall....Pages 304-305
Binaural Lateral Masking....Pages 306-307
Stereophonic Localization: Franssen’s Data....Pages 308-309
The Precedence Effect (Haas Effect)....Pages 310-311
Bauer’s Stereophonic Law of Sines....Pages 312-313
Pressures and Pressure Levels Generated by a Variety of Sound Sources....Pages 314-315
Typical Male Speech Spectra....Pages 316-317
Hearing Threshold Shift as a Function of Age....Pages 318-319
Front Matter....Pages 320-321
Frequency Ranges of Musical Instruments and the Human Voice....Pages 323-323
Dynamic Ranges of Wind and String Instruments....Pages 324-325
Directional Properties of Brass Instruments....Pages 326-327
Directional Properties of Woodwind Instruments....Pages 328-329
Directional Properties of String Instruments....Pages 330-331
Front Matter....Pages 332-333
Octave Band Spectral Amplitude Distribution, Music Sources....Pages 323-323
Front Matter....Pages 334-337
Track Width Standards for Professional Magnetic Recording....Pages 339-339
Track Widths Standards for Consumer Tape Formats....Pages 340-341
Azimuth Losses in Tape Playback....Pages 342-343
Oxide Thickness Losses in Tape Playback....Pages 344-345
Spacing Losses in Tape Playback....Pages 346-347
Gap Length Losses in Tape Playback....Pages 348-349
Reference Surface Fluxivity Standards for Tape Recording....Pages 350-351
IEC (International Electrotechnical Commission) Equalization Standards for Professional Tape Playback....Pages 352-353
NAB (National Association of Broadcasters) Standard for Professional Tape Playback....Pages 354-355
AES (Audio Engineering Society) Standard for Professional Tape Playback at 76 cm/sec (30 in/sec)....Pages 356-357
Standards for Playback of Consumer Tape Formats....Pages 358-359
IEC to NAB Conversion at 38 cm/sec....Pages 360-361
IEC to NAB Conversion at 19 cm/sec....Pages 362-363
Standard Weighting Curve for Tape Flutter Measurements....Pages 364-365
Back Matter....Pages 366-368
....Pages 369-378