Sample rate and bit depth
When describing digital recording devices, two fundamental concepts are used: sample rate and bit depth. In this article, we will see what it is.
Sampling rate
The sample rate is the rate at which the logger captures samples of the input signal. When recording sound in digital form, in fact, individual samples or, in other words, values of sound intensity are recorded at separate points in time.
The sample rate for recording devices is usually the following standard values: 44.1 kHz; 48 kHz and 96 kHz. The higher the sample rate, the more samples will be taken in 1 second and the better the digital sound quality we will get as a result.
What is the meaning of these numbers? They mean the number of times the recorder reads the sound intensity value from the input signal per second. The sample rate is measured in kilohertz (kHz), 1 kHz = 1000 samples per second.
For example, if the recording is made with a sampling frequency of 48 kHz, this means that the sound recorder measures and records the sound intensity value 48,000 times per second.
This number may seem unimaginably huge, but here the phenomenon called Nyquist frequency is worth remembering. The Nyquist frequency is named after the person who first discovered it. Defines the highest sound frequency that can be recorded at a given sample rate.
In short, the maximum tone that can be digitally fed is about half the sample rate.
Therefore, when recording at a sampling frequency of 48 kHz, the maximum audio frequency that can be recorded is 24 kHz. This is sufficient, considering that the human ear hears frequencies on average from 20 Hz to 20 kHz.
Bit depth
When talking about digital recording devices, you can often hear the words “16-bit”, “24-bit”, and so on. Some mean the number of information units with which the value of each sample obtained from the digital recording can be represented.
The higher the value of this number, the more accurately you can record the value of each sample and the higher the sound quality you will get as a result.
Do not think that the greater the number of bits, that is, the greater the bit depth, the greater the intensity value that can be set. Here is meant representation precision.
Modern recorders are usually 24 bits wide. It should be noted that recording with a large bit depth takes up a lot of space on the storage device, but this is not so important, because modern media has a huge volume and is becoming more and more affordable.
