Differences between digital audio formats (MP3, AAC, FLAC, WAV files, etc.)
What are the main digital audio formats and what are the differences between WAV, MP3, AAC, FLAC and others?
Differences in audio files To discover all types of digital audio formats, you must first understand briefly and synthetically what digital audio means and how it was created.
It all starts with Pulse Code Modulation (PCM), the basis for digital audio, which was founded in 1937 and is characterized by two properties: sampling rate for measuring the waveform amplitude and bit depth for measuring possible digital values.
If the sound is continuous in the real world, this is not the case in the digital world.
To understand the difference, you can think of digital videos that consist of still images that change quickly and give the impression of continuous motion.
It is the same for audio and the amplitude of the sound waves in a digital format is not fluid, but changes according to certain criteria at predefined intervals.
Since I am not an audio technician or physicist to do simple things and understand what digital audio is, I have found a very explanatory analogy that I am trying to explain here.
The analog audio source can be thought of as the water flowing from an open tap and the amplitude of the audio waveform as the water temperature.
Sampling can be viewed as the frequency with which the finger is immersed in the flowing water per second
The more the finger is immersed in it, the more continuous the temperature changes become.
If you put your finger in the running water 44,100 times per second, it’s almost like holding your finger still all the time.
This is the idea behind the sampling rate.
In terms of bit depth, we should think that we’re using a thermometer instead of the finger.
If the water temperature is higher than that of the surrounding area, we will say that it is hot, otherwise it will be cold if it is below it.
Instead of only 2 options, we could mark 16 possible values for measuring the water temperature.
The bit depth can be viewed as the number of values with which the thermometer is to be used to measure the temperature. The more they are, the more accurate information is obtained.
Without losing ourselves technically, we are now seeing the most important digital audio file formats and their differences.
1) WAV and AIFF are lossless (i.e. uncompressed) PCM-based audio container formats with some minor changes in data storage.
.WAV or Wave is the standard format when you take a CD out of your computer (CD ripping).
A WAV and an AIFF can be converted into each other without changing the quality.
These audio formats are suitable for a stereo system (2 channels), they are sampled at 44.1 kHz (or 44100 times per second) with 16 bits (“CD quality”) and the files are approximately 10 MB per minute.
2) Lossless formats: FLAC (Free Lossless Audio Codec), ALAC (Apple Lossless Audio Codec) and APE
These formats compress audio using algorithms.
The difference between compressed files and FLAC files is that FLAC is specifically designed for audio and therefore has better compression rates without data loss.
As a rule, a .FLAC takes up half of the storage space of a WAV in megabytes and maintains the “CD quality”.
A FLAC can be converted to WAV without loss of quality and is the preferred format for those who want to listen to music with the best quality and great speakers.
3) Loss formats: MP3, AAC, WMA, Vorbis
.MP3 and .AAC files are the most common formats when you need to store music on a computer or phone and need to share or download music on the network and the Internet.
MP3 is a highly compressed “lossy” format that sacrifices a certain amount of audio quality for a significant gain in file size.
An MP3 has a size of approximately 1 MB per minute.
The difference to lossless formats is that if you convert the file to a less compressed format like WAV, the quality sacrificed during compression will not be restored.
The various lossy formats use different data storage algorithms, so they vary the size of the files with the same quality. For lossy formats such as MP3, the audio quality is measured using the bit rate value, which is generally specified in “192 kbit / s” or “192 kbit / s”.
The higher the bit rate, the more detailed the sound becomes.
