Digital Audio has revolutionized music playback. It was originally conceived as a means of addressing the massive inconvenience factor of analog playback, in the form of vinyl disks, cassette tapes and the like, and was even hailed as a fundamental leap in sound quality. The launch of the CD in 1982 was a major success, and within a decade had changed the face of the business forever. 30 years on, however, the very industry that spawned it – the music distribution business, not the music creation business – faces an existential crisis brought about by its own prodigal son. For the audiophile audience here, though, we mostly care about the issue that the threatened industry apparently couldn't care less about, that of sound quality, and we delight in the delicious irony of it all. Because digital audio is finally delivering what we want most of all. Great sound quality combined with real convenience.
Like analog audio, it is still a broad-brush-strokes medium. There is nothing about either that prevents anyone from creating and distributing content with low quality using a format designed to deliver a high-quality product. Low-quality reproduction equipment will still deliver low quality sound, even from the very finest recordings, and the highest-quality reproduction equipment still demands a commensurate budget. But on balance, most people will broadly agree that the average quality of music playback in today's digital age is significantly in advance of what it was in vinyl's heyday, particularly when you compare like-for-like in terms of cost.
I am going to write a series of columns on Digital Audio. Mostly, these will be of an unapologetically technical nature. The thing is, whereas there was a lot of art and craft involved in the reproduction of LPs, digital audio is seen to be a much simpler, more black and white thing. You've either got it right or you haven't. It is easy to reduce the whole topic to a set of simple numbers – bit depth, sample rates, and the like – and comfort yourself in the certain knowledge that if the numbers meet some easily-remembered criteria then there is little else you need to know. Of course, the truth is never as simple or as cut-and-dried as any of us would like it to be, and any in-depth discussion of why that is so must inevitably lead to the rabbit hole of technobabble.
So, if you are going to continue to read my columns, you need to prepare for a couple of things. First, mathematics. Now, I'm not to require you to learn any tedious theorems named for people with unpronounceable names. But I am going to refer to their existence from time to time, and explain what they prove and why they are important. Digital Audio is all numbers, after all, and once you reduce something to a bunch of numbers – even a colossal bunch of numbers such as a digital audio file –you can look to mathematics to tell you what is contained within those numbers, and what is not. For the most part, this can be done with both precision and certainty, although we'll need to call upon one or more of those unpronounceable names to accomplish that.
The second thing you're going to hear a lot about is DSD, which may both surprise and disappoint you. After all, isn't DSD that odd-ball audio format promoted enthusiastically by super-serious audiophiles? It requires enormous file sizes and special hardware and software to play it back. It is seriously fringe stuff. So why do you need to be concerned with it? Well, the fact is that the principles which underpin DSD are hard at work in almost every digital audio device you own, from the cheapest DAC chipsets built into your mobile phone, to the most expensive stand-alone audio DACs. Even the ADCs which convert the recording studio's microphone feeds to digital audio numbers do so based on the principles that underly DSD. So, at some point, if you want to understand Digital Audio, you're going to have to understand DSD.
For all the fact that digital audio has moved the audio playing field from the art and craft of vinyl to the mathematics and computers of digital, it still hasn't managed to completely disconnect itself from some of the strange things that made us scratch our heads back in the day. Lest we forget, there was a lot of loud protest at the notion that one might wish to test an amplifier by connecting it to loudspeakers and listening to it, rather than hooking it up to a honking great resistor and an oscilloscope. And hoots of derision were howled at the idea that the bit of a turntable that makes the record go round actually has a greater impact on the sound than either the tonearm or the cartridge. That such "radical" ideas were quickly assimilated into the mainstream was made possible at least partially because they could be acceptably assigned to the 'black art' aspect of the audio art.
So when the digital world starts to encounter its modern equivalents we prefer to think that there are no longer any of these 'black arts' still in play, and this – together with the internet – causes major rifts. Why should a USB cable affect the sound of a digital audio system? Or even the Ethernet cable that connects the computer to a NAS, for example. Why should a bunch of numbers stored as a FLAC file sound different from the same numbers stored as a WAV file? Indeed, the strange things that happen in the world of digital audio can sometimes be the strangest of all.
All these things and more shall be added unto thee, at least they will if you stick with my column for a few weeks. Digital audio is an endlessly fascinating – albeit challenging – topic. Happy reading!
Richard Murison enjoyed a long career working with lasers, as a researcher, engineer, and then as an entrepreneur. This enabled him to feed his life-long audiophile habit. Recently, though, he started an audiophile software company, BitPerfect, and consequently he can no longer afford it. Even stranger, therefore, that he has agreed to serve in an unpaid role as a columnist, which he writes from Montreal, Canada.