Audio Engineering

482 Chapter 15 At this stage you will need to be sure you are confi dent that you appreciate that the combined effect of the ant ...

Representation of Audio Signals 483 A very simple form of DAC is based on switching currents into a virtual earth summing point. ...

484 Chapter 15 2R resistors is halved at each stage the current that is switched is also halved. The currents are summed at the ...

Representation of Audio Signals 485 There are many variations on the use of this technique with one common approach being to spl ...

486 Chapter 15 itself. The error can be referred to as quantizing distortion, granulation noise, or simply quantizing noise. One ...

Representation of Audio Signals 487 Unfortunately, it is also quite a problem to design accurate and stable quantizers. The prob ...

488 Chapter 15 A powerful alternative test method uses a sinusoidal waveform and checks the amplitude probability density functi ...

Representation of Audio Signals 489 which an apparently high-quality signal can be delivered using fewer bits. The telephone com ...

490 Chapter 15 Convert VRT VRT R 1 R O 1 O 8 R R 2 R R R 2 Vinput Outputs Latch 255 to 8 encoder Differential comparators (255) ...

Representation of Audio Signals 491 The encoder will need to have the matching inverse characteristic in order that the net tran ...

492 Chapter 15 Delta sigma modulators made an early appearance in digital audio effects processors for a short while. One of the ...

Representation of Audio Signals 493 of samples with a low-pass fi lter set to remove the components between the top of the audio ...

494 Chapter 15 quantization noise over four times the spectrum, thus only 1/4 of the noise power now resides in the audio band. ...

Representation of Audio Signals 495 to arranging the encoded data in the required format. The principle in this encoder is simil ...

496 Chapter 15 published in 1975, the principles have not changed, indeed it is salutary to read the book and to realize that so ...

Compact Disc John Linsley Hood 16.1 Problems with Digital Encoding ............................................................. ...

498 Chapter 16 Input waveform Time Digitised ‘staircase’ waveform Permissible step levels Figure 16.1 : Digitally encoded/decode ...

Compact Disc 499 audio bandwidth of the incoming signal. However, in practice, additional digital “ bits ” will be added to this ...

500 Chapter 16 fs is the sampling frequency and fm is the upper modulation frequency. Because of the way in which the sampling p ...

Compact Disc 501 This diffi culty is illustrated by the graph of Figure 16.4 , which shows the relative group delay and phase sh ...