Digital sound is typically 44,100 samples per second. That sounds like a freakin lot of samples per second but it’s too low and that’s the problem. Really high quality sampling of sound takes place at 2,822,400 samples per second. This is known as SACD (Super Audio CD) developed by Sony and Philips. That’s 64 times greater than 44,100 samples per second. Currently, the best digital audio recordings have a sample rate twice as high as SACD. Or 128 times the typical 44,100 sample rate.
The problem is that CDs don’t hold enough information to be able to support SACD. You’d only get a couple of minutes or less of such audio on a CD. That is probably the historic rationale for commercial audio being typically 44,100 samples per second: the file sizes are not too big.
When I listen to typical digital audio, what I notice, if I crank it up–and I like to crank up music, typically–is that there’s no presence to the recordings. Some vinyl albums I had, when played on decent stereos–the stereos didn’t have to be top of the line, but they had to be OK–sounded pretty much ‘live’. They had presence. But digital audio, it can’t break through from the other side, as it were.
The reason why the sampling rate is important is this. You’ve seen wave representations of sounds. You know sound is waves of air–that’s what sound is. Well, the samples are points used to construct those waves. Imagine a curve. Any curve. Now imagine four points on that curve. Now draw straight lines from the first point to the second point to the third point to the fourth point. Those lines will look a little bit like the curve but not much, probably. You need more than four sample points so that when you draw lines from point to point, you get something that looks more like the original curve.
Similarly, the higher the audio sample rate, the better the audio software can figure out what the sound actually sounded like. Low sample rates result in sound that lacks the highest of subtleties we as feeling humans are able to infer from sound, and that’s its presence. All that info we pick up in live audio–how far away it is, the composition of what’s being struck, all the really subtle information that makes it ‘live’–is simply undetectable at lower sample rates.
So what? So what that presence isn’t a part of contemporary recorded sound experience? So what? What does it matter?
Well, it’s a question of whether it can break on through from the other side, isn’t it? What we get, currently, is a good idea of the sound. Not the mind blowing experience you really do get from great audio rendered in recordings with presence. Which explains why live performance is so esteemed these days over recorded sound.
As time goes by, digital audio will increase in the typical sample rate. Cuz all it takes is good technology to support it. Not impossible technology by any means. Eventually the typical digital audio sample rate will match and even surpass the good old days of vinyl.
But, in the meantime, we live in age of merely the idea of the audio in recorded sound. Play me something Platonic baby.