BIT DEPTH
-translated from eurpean language-
As a digital music producer, you will soon come into contact with the terms Sample Rate and Bit Depth. These terms are often experienced as complicated and are also used interchangeably. Starting today, you will no longer have to make those mistakes, because you have LesinProducing and we will do our best to explain it to you as well as possible. So here we go!
As a digital music producer, you work 99% of your time on your computer or laptop. In order to record and edit sounds with a computer, the sound must be translated into the digital language that a computer understands, that is, “binary codes” (with all those zeros and ones).
SAMPLE RATE
Sample Rate Image A movie is actually a complete series of images that are put together, which our brain then interprets as a moving image. This is how it works with digital audio. Digital audio is basically a series of snapshots, which our brain experiences as one continuous sound. The frequency with which snapshots of the audio are taken, we express it in “Sampling frequency”. The greater the number of snapshots taken, the more detailed the result. In the world of digital audio recording, 44.1 kHz and 48 kHz are / were the most common sample rates. “But what exactly does 44.1 kHz mean?” I heard you think!
44.1 kHz means 44,100 “snapshots” that are taken per second. At 48 kHz this is 48,000 “snapshots” per second. Today you come across sound cards that support recordings of up to 96 kHz or even 192 kHz. That’s respectively 96,000 and 192,000 “snapshots” per second.
Okay, so far, because I know you have a few questions on your mind right now. Let’s see if we can answer your questions right away:
Question 1: If my sound card supports 96kHz recording, for example, where can I configure this?
Answer: In Cubase you can set the sample rate in Project -> Project Settings. In Logic X, do this in File -> Project Settings -> Audio.
Question 2: Is the difference between 44.1 kHz and 96 kHz audible?
Answer: The difference between 44.1 kHz and 96 kHz is almost inaudible.
Question 3: If we don’t experience / hear 92 kHz as “better”, what good is it?
Answer: To answer this question, we are introducing a new term, the “Nyquist Frequency”. Simple explanation: generally people can hear frequencies from 20Hz to 20,000Hz (= 20kHz). If you want to record a 20 kHz sound source, it must have a sampling frequency of at least 40 kHz. The “Nyquist frequency” of the 40 kHz sample rate, in this case 20 kHz. In this setting, 20 kHz is the highest frequency that can be recorded with a 40 kHz sample rate. Some musical instruments are said to have a higher range than our hearing (20 kHz). According to some, it is important to record these instruments as well as possible, although these instruments contain frequencies that we do not hear directly at first, but that we can feel / experience. If you want to achieve this,
Question 4: Why not record everything at the highest possible sample rate?
Answer: One reason is that the higher the sample rate, the larger the storage space. For example, if you need 5 MB of storage space for a few seconds of audio at a sampling rate of 48 kHz, you will need no less than 4 times more storage space for the same seconds at 192 kHz, that is, 20 MB.
BIT DEPTH
When Sample Rate takes vertical “snapshots”, the bit depth is based on the resolution (sharpness of the translation). Easy said; the higher the bit depth of the “digital translation”, the sharper the “translated” result. The result is a nice smooth waveform at higher bit depth. So you can take 44,100 “snapshots” with the sample rate, but if the resolution (depth of supply) is not sharp enough, the result will not be a smooth waveform. Bit depth is also about dynamic range. With each +1 bit, a dynamic range of + 6dB is added. For example, a 16-bit bit depth has a 96 dB dynamic range, and a 24-bit has a 144 dB dynamic range. For CDs, use 16-bit and for DVDs, 24-bit.
