340 



INDEX 



Larynx, 318, 



artificial, 318 

 Line microphone, 214 

 Longitudinal vibration of bars, 44 

 Loudness, 320 



Loud speaker, direct radiator, 111 

 baffles, 127 



cabinet back enclosed, 130 

 cabinet open, 129 

 diaphragm, 142 

 double coil, double cone, 123 



single cone, 121 

 efficiency, 112 

 feedback, 135 

 field structures, 143 

 horn combination, 135 

 labyrinth, 132 

 mechanical networks, 124 

 multiple, single cone, single coil, 119 

 nonlinear distortion, 136, 262 

 phase inverter, 131 

 power output, 113 

 single coil, double cone, 120 



single cone, 112 

 transient response, 138, 268 

 voice coils, 142, 171 

 horn, 145, 



amplitude of the diaphragm, 164 

 compound, 168 

 compressed air, 242 

 diaphragms, 171 

 efficiency, 145 



air chamber, effect of, 150 



generator, effect of, 153 



initial, 146 



mass, effect of, 149 



temperature, effect of, 155 

 field structures, 171 

 multiple horn, multiple channel, 167 



single channel, 169 

 nonlinear distortion, 156, 262 



air, chamber, effect of, 157 

 gap, effect of, 161 



subharmonic, 162 



suspension, effect of, 160 



throat, effect of, 156 

 power handling capacity, 163, 164 

 single horn, single channel, 164 



voice coil, 163, 171 



walls, absorption, 171 

 vibration, 171 

 operating in, automobile, 299 



living room, 298 



theatre, 282 

 testing, (see testing of loud speakers) 



Masking, 322 



Measurement of, absorption coefficient, 

 275 

 acoustic impedance, 271 

 loud speakers, 253 

 microphones, 245 

 noise, 273 



reverberation time, 274 

 telephone receivers, 269 

 transmission coefficient, 276 

 Measurements, 245 

 Mechanical, analogies, 49 

 compliance, 52 

 elements, 53 

 impedance, 59 

 ohm, 59 



phonograph, 233 

 reactance, 59 

 resistance, 50, 59 

 system, one degree of freedom, 54 

 three degrees of freedom, 61 

 two degrees of freedom, 60 

 vibrating systems, 36 

 Membrane, circular, 40 

 Microphone, batteryless telephone, 213 

 calibration, (see calibration of micro- 

 phones) 

 directional efficiency, 221 

 high sensitivity, 224 

 highly directional, 213 

 line type, 214 

 simple, 214 

 with, delay, 216 



pressure gradient, 218 

 parabolic reflector, 213 

 ultradirectional, 220 

 hotwire, 212 

 lapel, 212 



motional impedance, 224 

 nonlinear distortion, 223 



