In the first of a series, mastering engineer Joe Lambert answers one of the many FAQs he regularly fields:
Q: Joe — bit rate: 16 or 24? Does the bit rate of a sound file make a big difference?
A: Here is a little background:
Bit rate is the amount of information (in bits) recorded per second. I like to think of it as pieces of data or music, and with 16-bit audio, there are 65,536 possible pieces.
With every bit of greater resolution, the number of pieces double. By the time we get to 24 bit, we are up to 16,777,216 pieces per second. Each bit gives you 6dB of dynamic range, so 16-bit gives you 96dB of dynamic range and 24-bit gives you 144dB dynamic range.
24-bit has room for 256 times the data, giving you better resolution. Having all of this dynamic range gives you greater separation between audio and noise floor. With hard drive space so cheap now (I paid $1000.00 for my first 1 Gb drive in the mid-90’s!) there is no good reason not to get all the bits we can.
So is it easy to hear the difference? Sometimes…
The easiest way for me to hear the difference is to listen to the noise floor. Put up a couple mic’s in a room and just listen to the noise coming through your system: It’s dramatically lower at 24-bit.
This gives you the ability to record at lower volumes and get better resolution. When recording a bunch of tracks, as well as adding effects, this is especially important, because noise can add up quickly.
How does this affect my final master if it’s going to end up 16-bit?
The goal is to get all the details of your music that you put down. So the more detail we have to start with, the more you will end up with in the final product regardless of the end format, which gives your mixes better imaging, better top end detail, and clarity.
The Moral of the Story:
I like to capture all my files at 24-bit, then I can decide what the end format will be and down sample when needed.
Joe Lambert is owner and chief engineer of Joe Lambert Mastering (JLM) in Brooklyn, NY. To send Joe your question and visit JLM, go to http://www.joelambertmastering.com.