If you’ve started caring about audio, you’ve probably seen something called “bit depth”. The thing is … what the hell is this is he? Well, we are here to help.
First of all, bit depth is one of the two measures involved in measuring the quality of a piece of digital music. The first of these is the sampling rate. We’ve covered what it is here, but for a quick recap, it’s the number of “samples” taken per second from an analog sound wave to turn it into digital.
Think of it like the audio version of a TV’s frame rate: lots of individual dots played one after another to make the sound feel like always smooth. And, if we continue this metaphor, the bit depth is the resolution, in fact the amount of data that there is in any of these points or samples.
Of course, bit depth is not the same as TV resolution, but it’s a useful way to visualize the term.
Anyway, let’s dive a little deeper. There are several bit depths, as this beautiful diagram shows:
The most common bit depth is 16 bit, this is the CD standard and what you will find with the majority of FLAC files, which is a lossless music format.
This means that the digital audio file contains 16 bits of information in each sample. When combined with the CD’s sample rate (44.1 kHz), this means that every second 44,100 samples are taken and each of them contains 16 bits of data. Simple, right?
What impact does bit depth have on music?
Well, if a bit depth is too shallow, the quality will suffer. Specifically, you will find that a good portion of the weak sounds will be lost. On recordings or files with a high bit depth, you will have a much more accurate reading – up to a point. But we’ll get to that shortly.
Something bit depth controls is the dynamic range of a sound. This is the difference between the silence and volume level of the respective parts of the audio. And, the higher the bit depth (8-bit, 16-bit, 24-bit, and 32-bit being the most common), the more dynamic range is available.
But… this is where we come to a crossroads.
Apologies, audio nerds, but it’s incredibly unlikely that anyone will hear the difference between 16-bit bit depth and anything higher. There is an argument to be made for recording audio with a bit depth greater than 16 bits (this is mainly just to give the engineer as much flexibility as possible), but for listeners? These 24-bit FLAC files are rarely worth the space.
Either way, we’re coming to the end of this piece, so let’s freshen up. Basically, bit depth describes the amount of data taken per sample in an audio file. Take a look at this to help you:
And the other thing to remember? Bit depth controls the dynamic range of the tracks, which can be thought of as the difference between the quietest and loudest sounds in an audio piece. Phew, haven’t we learned some stuff?
This piece is part of a series around CDs and you can find this Big Beefy Boy post here. Come on, click, you’ll love it.
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Published March 8, 2021 – 10:17 UTC