First things first. An Introduction to Digital Audio is NOT a "How To" manual in the usual sense. Think of it more as Digital Audio 101 in a College of your choice. More a textbook and service manual than a "Buy a Sennheiser ME66 and a Beachtek adapter and you'll make nice audio". No, this is the nuts and bolts of digital audio from the ground up.
It was interesting to me that the back cover included quotes from various reviewers like HI-FI Magazine and Mobile Radio Technology. That should have been a tip off right there! When I first opened the book there was the usual "let's explore what digital audio really is" section. Most books cover that part perfunctorily and then move on to equipment choices and microphone placement. This book pulls you into the world of digital audio like Kurt Russell got pulled into the computer in TRON. We're going to see EXACTLY what happens when you record a signal on your DAT player or MiniDisc recorder.
Originally written in 1994, Watkinson was prescient in his statement that digital audio gives the average person tools that were either un-affordable or simply unavailable with Analog equipment. He accurately predicts the rise of digital data streams coming into our homes to be enjoyed on demand (digital cable services).
His introduction to the subject of digital audio proceeds just as any textbook would. "What is an audio signal?" Beginning with the explanation of an analog audio signal, Watkinson proceeds to point out the weakness of the analog signal and the strengths of the digital one.
Make no mistake, Watkinson knows his stuff here. He breaks down the subject into small digestible (if not somewhat dry) portions that hammer home the concept of digital audio as data (which of course it is).
Chapter 2 gets into the physics of audio and I mean PHYSICS! Any book that covers periodic and aperiodic signals along with illustrated waveforms, models of the human ear, tables and graphs of signal response, mathematical models of frequency and pressure, and contains the following sentence; "Figure 2.10 shows an uncoiled basilar membrane with the apex on the left so the usual logarithmic frequency scale can be applied.", falls WAY out of the realm of the average person's search for better audio. Each of the 11 chapters in the book cover their subjects in the same detailed manner. There are schematics and drawings galore, all of which are well laid out and to the point, but very technical.
There is very little that Watkinson misses in this book pertaining to digital equipment. He delves deep into the whole structure of digital data, with copious charts and diagrams explaining each section covered down to the last bit and byte. He covers computer systems, which as he points out are critical to digital audio. More charts and diagrams dissect the inner working of your computer until you feel as though you are reading an old assembly language text. He does manage to bring us back to the audio subject right at the point where we are scratching our heads, but again, it's DEEP. This is not a book that you are going to read at lunch hour to pick out a couple of neat tricks for that event you're shooting on the weekend. As a matter of fact, there are no tricks in this book at all, just solid theory and technical information that explains the workings of digital recording equipment.
There is no doubt that Watkinson knows his subject inside and out. His explanation of PCM (Pulse Code Modulation), Compression schemes, Networked Audio, MPEG audio compression, Sub Band and Transform coding etc. is thorough and complete. The question is, does the average person searching for good clean audio really NEED to know all this? If one is planning on a career as an audio engineer, then I would say that this book will lay the groundwork and foundation for entry into that field. It's great to know how a magnetic disc drive assembles data and then retrieves it, but this isn't something that I'm terribly interested in as I'm recording my audio. A good analogy is the computer user who doesn't need to know how memory is addressed, packets of data are stored and delivered, they just want to know that the word processor will pop up when they hit the icon for it.
If you are an information junkie, then you will certainly have more than your share of minutiae to digest in this book. Plan on spending a semester reading this over and over again and if you can retain all the information therein, you will probably know more than the engineer at your local recording studio. Whether that will make you produce better audio, however, remains to be seen. The fellow who can explain how the hard disk writes information and how the printer knows where to shoot the little spots of ink doesn't necessarily have the talent to write a good novel.
An Introduction to Digital Audio is a comprehensive book in every respect, but not for the faint of heart or those wishing to have guidance of a more practical nature in producing their audio.
I rate An Introduction to Digital Audio (4 1/2 Cows) for aspiring Audio Engineers and don't recommend this book to those who are looking for something more practical and less "Academic".