Explanation of the sample rate, bit depth and bit rate
This is what happens when you compress audio files
High-resolution streaming and audio promise us particularly good lossless sound when playing digital music. But what exactly does that mean? Sample rate, bit depth, and bit rate are explained.
16-bit 44.1 kHz – CD Quality: This slogan is often used when marketing high-resolution and lossless audio formats and equipment. But what exactly is it about?
The quality of digital audio signals is primarily determined by three things: sample rate, bit depth, and bit rate.
In principle, you have to imagine that a digital audio signal is not a constant flow of information. Rather, music is divided into very, many small “slices” (samples), each of which carries the information for the digital-to-analog converter in a short section.
The more samples a signal has per unit time, the more precisely the original analog signal can be mapped.
The sample rate reveals how tight the samples are: the 44.1 kHz of a CD represents 44,100 samples per second.
Bit depth
Bit depth (resolution) is specified in “bits” and indicates how many different values each sample can assume. With 16 bits (CD quality), this is 2 ^ 16, that is, 65,536. The recording studio usually works with 24 or even 32 bits.
This is where many high-resolution formats come into play that also promise studio quality at 32-bit resolution.
▶ ︎ MP3, FLAC, ALAC, WAV – the most important music formats in comparison
Bit rate
The bit rate (bandwidth) of an audio file in uncompressed formats is initially nothing more than the summary of the sample rate, the bit depth and the number of channels. It is specified in kBit / s and therefore provides an initial characteristic value for evaluating the quality of a file.
Example: A stereo CD stores two tracks at 44.1 kHz with a bit depth of 16 bits. This means that its bit rate is 44.1 kHz x 16 bits x 2 channels = 1411.2 kBit / s
