How Different Wav, Flac and MP3

In the digital music era, people are always trying to create different audio formats to reduce the size of the music file stored but still have to keep the perfect sound quality. Each audio format will use different algorithms to sample, encode and retain the characteristics of the original music file.

The question is, between today’s countless digital music formats, from MP3, WMA, AAC to FLAC, ALAC, APE or WAV, AIFF – how are they different in quality, which one should we listen to, and how do we store them? What format?

First, we will need to learn the basics of audio formats with the concept of PCM (Pulse-Code Modulation). Born in 1937, PCM was one of the first technologies to support the conversion of sound wave signals (analog) into digital. Thanks to PCM, we can listen to music on computers, CD players instead of vinyl or cassettes like our ancestors.

Two components characterize PCM:

+ Sample rate: indicates the number of times the audio signal is measured and sampled in one second.

+ Bit-depth: To put it simply, bits are binary codes (numbers 0 and 1) used to create data – or music files that we download. For digital audio, the bit-depth will indicate the number of bits used to store the audio signal.

In theory and practice, high-resolution audio is more detailed than low-resolution audio. However, it also depends on other factors such as recording quality, sound system (DAC – Digital to Analog Converter), most importantly, human hearing. Listening to mp3 with lossless is the same.

In the past, digital music was usually recorded on 16-bit CDs with a frequency of 44.1 kHz. However, with the rapid development of audio technology, recordings with resolutions up to 24-bit, 32-bit with sample rates of 96khz, and even 192khz appear more and more popular.

In essence, the world’s popular audio formats will be divided into three groups: uncompressed, compressed but data-preserving (lossless), and compressed without preserving data (lossy).

Uncompressed: WAV, AIFF

As the name suggests, this audio format is original, uncompressed, and has a fairly large capacity like WAV and AIFF. According to this formatting standard, every second, audio is sampled at a frequency of 44.1 kHz (44100 times/second), each sample is represented by 16 bits of data. So for 1 minute of sound, we have:

44100 Hz x 2 left and right channels x 2 bytes (16 bits = 2 bytes) x 60 seconds = 10,584,000 bytes = 10.1 MB.

That explains why, normally, a 750MB CD will store about 74 minutes of music, corresponding to the standard bit rate of the original sound 44100 Hz X 2 channels X 16bit = 1411 kbps (Kilobits/second)

WAV

WAV is an uncompressed audio file format based on the PCM format, developed by Microsoft and IBM in 1991 to make it easier for users to use on Windows machines. However, at present, WAV has become popular on both Mac and Windows.

AIFF

Like WAV, AIFF is also based on PCM technology but developed by Apple for its Macs. In addition, AIFF has other versions, AIFF-C and Apple Loops, used by GarageBand and Logic Pro music-making software. Although designed for Mac, Windows machines can still use this format normally.

Lossless Compression: FLAC, APE, ALAC

If you use a computer, you will be no stranger to Zip or Rar – 2 software that can reduce the file size significantly, but its data remains the same. That is also the purpose of lossless compression: preserving the original audio signal.

How to do that? Simply, it uses an algorithm to find the repetition pattern of the data, then finds another way to display it more optimally, using fewer data. For example, instead of the string “ggggg eeee nnn kkkkkkk,” we have a good but much less literal interpretation: “gx5 ex4 nx3 kx7”.

Thus, the lossless compression algorithm will ensure the original quality after decompression because it does not remove anything; it just displays other data.

The audio data in a recording is extremely diverse and uses a lot of data, so the compression is not as effective as Zip or Rar. Currently, the highest possible compression of lossless compression is about 1/3 => 1/2 of the original capacity of the original audio; each lossless album will have a capacity of about 200 to 300 Mb.

FLAC (Free Lossless Audio Codec), ALAC (Apple Lossless Audio Codec), and APE (Monkey’s Audio) are three popular lossless formats today. FLAC is the most popular and supports playing on many music players, APE decodes more complex, and Apple’s ALAC is not as popular as the other two formats.

Compression does not preserve data (Lossy): MP3, AAC, WMA, Vorbis,…

When the Internet was slow, hard drives were expensive; downloading or storing a music CD with a capacity of more than 700 MB took a lot of time and effort. That’s why “lossy” formats were born, sacrificing sound quality and accuracy to reduce music file size.

In addition, the human ear can only perceive sounds with frequencies between 16Hz – 20KHz; the compression algorithm will eliminate frequencies outside this range. That saves both the number of samples and the number of bits from encoding, thereby saving maximum capacity.

Mp3 music is usually compressed with bit rates of 128kbps up to 320kbps – only 1/10 of the bit-rate of WAV (1411kbps). It’s easy to see why 128kbps mp3 music only takes about 1MB per minute, and a CD can store hundreds of songs.

So what is the cost of saving space? During compression, the fake sound will be “compensated” to the parts it removed, resulting in distortion compared to the original sound. Just try to compare a 64kbps mp3 with a lossless compressed file or a track in the original CD and easily notice this change.

In addition, once we have compressed it to a lossy format, we cannot convert it back to its original quality like lossless. WAV can be converted to FLAC and vice versa and still retain the sound quality, while WAV to mp3 128 kbps will permanently lose the original file’s quality.

However, lossy formats such as MP3, AAC, WMA, Vorbis are still commonly used today because of their compactness. Suppose you are not too picky in listening to music or simply listening to Pop. In that case, Rock, Dance (rather than classical music, vocals with high sound frequencies, many instruments), the lossy format can completely respond to meet your needs.

So, here you can distinguish the origin and difference of WAV, FLAC, and MP3 – popular digital music formats today. Which type of listening to, which type to store will depend on three main factors:

+ What sound quality do you want?

+ How good is your listening ability?

+ How capable is your audio device (speakers, radio, DAC/AMP, headphone,…)?

I think that when I started researching and downloading high-quality lossless or hi-res music – that means your need to enjoy music has changed.