A lot of competent audio engineers working in the field today have some real misconceptions and gaps in their knowledge around digital audio.
Not a month goes by that I don’t encounter an otherwise capable music professional who makes simple errors about all sorts of basic digital audio principles – The very kinds of fundamental concepts that today’s 22 year-olds couldn’t graduate college without understanding.
There are a few good reasons for this, and two big ones come to mind immediately:
The first is that you don’t really need to know a lot about science in order to make great-sounding records. It just doesn’t hurt. A lot of people have made good careers in audio by focusing on the aesthetic and interpersonal aspects of studio work, which are arguably the most important.
(Similarly, a race car driver doesn’t need to know everything about how his engine works. But it can help.)
The second is that digital audio is a complex and relatively new field – its roots lie in a theorem set to paper by Harry Nyquist 1928 and further developed by Claude Shannon in 1946 – and quite honestly, we’re still figuring out how to explain it to people properly.
In fact, I wouldn’t be surprised if a greater number of people had a decent understanding of Einstein’s theories of relativity, originally published in 1905 and 1916! You’d at least expect to encounter those in a high school science class.
If your education was anything like mine, you’ve probably taken college level courses, seminars, or done some comparable reading in which well-meaning professors or authors tried to describe digital audio with all manner of stair-step diagrams and jagged-looking line drawings.
It’s only recently that we’ve come to discover that such methods have led to almost as much confusion as understanding. In some respects, they are just plain wrong.
What You Probably Misunderstand About Bit Depth
I’ve tried to help correct some commonly mistaken notions about ultra-high sampling rates, decibels and loudness, the real fidelity of historical formats, and the sound quality of today’s compressed media files.
Meanwhile, Monty Montgomery of xiph.org does an even better job than I ever could of explaining how there are no stair-steps in digital audio, and why “inferior sound quality” is not actually among the problems facing the music industry today.
After these, some of the most common misconceptions I encounter center around “bit depth.”
Chances are that if you’re reading SonicScoop, you understand that the bit depth of an audio file is what determines its “dynamic range” – the distance between the quietest sound and the loudest sound we can reproduce.
But things start to go a little haywire when people start thinking about bit depth in terms of the “resolution” of an audio file. In the context of digital audio, that word is technically correct. It’s only what people think the word “resolution” means that’s the problem. For the purpose of talking about audio casually among peers, we might be even better off abandoning it completely.
When people imagine the “resolution” of an audio file, they tend to immediately think of the “resolution” of their computer screen. Turn down the resolution of your screen, and the image gets fuzzier. Things get blockier, hazier, and they start to lose their clarity and detail pretty quickly.
Perfect analogy, right? Well, unfortunately, it’s almost exactly wrong.
All other things being equal, when your turn down the bit depth of a file, all you’ll get is an increasing amount of low-level noise, kind of like tape hiss. (Except that with any reasonable digital audio file, that virtual “tape hiss” will be far lower than it ever was on tape.)
That’s it. The whole enchilada. Keep everything else the same but turn down the bit depth? You’ll get a slightly higher noise floor. Nothing more. And, in all but extreme cases, that noise floor is still going to be – objectively speaking – “better” than analog.