Analog vs. digital. What's the difference and does it matter?

I think the best way to describe analog vs digital is to just slog through an explanation. Besides, I've been trying to think of a killer analogy for days and all analogies limp so I ain't got nothin'. Here’s goes.

Analog is waves and digital is steps. And because of this fact, everyone generally agrees that analog does a better job of reproducing sound waves than digital. In fact, some would argue that digital can't actually make curves, only approximate them, and they would be right. Magnify any digitally reproduced sound wave enough and you will see steps; no so with analog.

Making digital sound analog.

There are two keys to making digital sound like analog. The first is the sampling rate, or the number of steps within a certain time frame (typically one second). Think of samples as pictures in a reel of film. When you have enough, you perceive smooth, fluid motion. Not enough and you've got claymation. Sound is the same way. A high sampling rate means smoother, more fluid sound. A low enough sampling rate could lead to a machine gun effect. Also, sampling rate affects frequency response, which is why high sampling rates are required for high frequencies. The second factor is what's called bit depth. This is a little geeky but the concept is simple. Think of bit depth as the accuracy of each sample. When you have a high bit depth, each sample is like a high resolution photo shot by an DSLR. With a low bit depth, you're in camera phone 1.0 land. Bit depth determines dynamic range.

So, CDs with their crummy bit-depth and sampling rates sound horrible, right?

CDs use a sampling rate of 44.1 KHz (44,100 times per second) and a bit depth of 16. From everything I’ve read, this should theoretically do the trick, but most decent digital recording gear for studios samples at up to 88 KHz or even 96 KHz and uses a bit depth of 24. To play back this level of quality, you need a DVD-Audio or Super Audio CD (SACD) player and who has one of these? But, here’s the KICKER: According to Wikipedia, a year-long double blind test conducted by the Audio Engineering Society and using professional recording engineers revealed that people could pick between SACD and CD recordings with roughly a 50% success rate (same as chance). This blows my mind because I KNOW my Super Audio CDs sound way better than my standard CDs. Weird.

The future.

As digital relentlessly improves, I’m sure there will be a point at which even the editors of The Absolute Sound agree that it’s better than analog, but right now, the debate rages. As for me, even though the Audio Engineering Society says I’m imagining it, I will continue to make sure that my studio recordings are mostly 24-bit / 88 KHz* because they sound better, dammit.

If anyone out there has thoughts on all this, I’m (ahem) all ears.


* I use 88 KHz instead of 96 KHz because it means I can open files from Hyde Street at home.