Audio Engineering

242 Chapter 8 (cf. peak) and also specifi ed with a steady sine wave, and for power amps in particular, with loading—all unless ...

Interfacing and Processing 243 provides 100 W at normal drive levels (0 dBu say). The  13-dBu/3.5-V rms input drive needed for ...

244 Chapter 8 However, as just discussed, a specifi c lower value, as low as 30 mV, may be best (at least in high NFB circuits) ...

Interfacing and Processing 245 Impedances (often abbreviated ‘ z ’ ) are rated in ohms ( Ω ). As in this case, ohmic values are ...

246 Chapter 8 8.1.2.3 Audio is Not RF Precise “ impedance matching, ” where specifi c impedances (often 50 or 75 ohms) must be a ...

Interfacing and Processing 247 alike, an amplifi er’s individual input impedances may be ultra-matched. Since with voltage match ...

248 Chapter 8 is accidentally connected to another’s input. Added protection would add complexity, increase the cost, and likely ...

Interfacing and Processing 249 required to handle just one frequency band alone,^8 the signal was split among up to 10 line driv ...

250 Chapter 8 Figure 8.1 shows how the input impedance of a typical, minimal power amplifi er with an unbalanced input ( Figure ...

Interfacing and Processing 251 Figure 8.3 shows how the same input stage’s impedance varies (without changing anything else) as ...

252 Chapter 8 8.2 Radio Frequency Filtration ................................................................................... ...

Interfacing and Processing 253 frequencies l0,000 times higher. However, special radio transmissions (for submerged submarines, ...

254 Chapter 8 8.3.3 Balancing Requirements 8.3.3.1 Input Impedances The norm in modem pro-audio equipment is 10 k Ω across the l ...

Interfacing and Processing 255 8.3.4.2 What Does CMR Achieve? Common mode rejection action prevents the egress and build-up of e ...

256 Chapter 8 8.3.4.3 What CMR Cannot Do Like the stable door, the one thing CMR can’t do is remove unwanted noises that are alr ...

Interfacing and Processing 257 8.3.4.4 Relativity Rules The size of common mode (noise) signals is not fi xed or even very predi ...

258 Chapter 8 Subsonic ( infrasonic ) information , comprising both music content and ambient information, may occur below the h ...

Interfacing and Processing 259 8.4.3 The Pro Approach Subsonic fi ltering may be regarded as an essential part of editing and sw ...

260 Chapter 8 switchable (or programmable or otherwise controllable) so that its action can beremoved positively when not requir ...

Interfacing and Processing 261 be an acceptable point for the bass response low cutoff frequency (f3 L ). The result is consider ...