Understanding Audio File Formats: FLAC, WMA, MP3
These days, almost every device plays MP3 files. Many devices also support a wide variety of file formats. You may be wondering, "Why would I want to use any audio format other than MP3?" While MP3 has become the industry standard for audio playback, iTunes uses its own Apple proprietary format, and Windows Media uses its own in place of MP3s. You also have people who want to copy their CDs to digital files in order to archive their music collection as high-quality audio files on their home computers. Those people will undoubtedly want a higher quality file than a MP3 or Windows Media file will allow.
But how do you know which file format will sound the best? Many devices — including RetroSound® RetroRadios™ – are capable of playing back multiple file types such as MP3, WMA and FLAC (more about these file types in a moment). Before you decide which format is going to be best for you, first you need to understand what bitrates are and the difference between lossy and lossless compression.
Bitrate
Most people who are familiar with digital audio have heard the word "bitrate," and have some kind of an idea of what that term means. In general, the higher the bitrate of your audio file, the higher the quality of the sound.
The word "bitrate" actually refers to the amount of data (in bits) that is processed in one-second. The bitrate is measured in kbps (kilobits per second). The idea here is: more audio data = higher quality audio, since there is more audio data to decode. In essence, when the bitrate is reduced using lossy compression, audio data is removed — which results in reduced sound quality. Because a higher bitrate results in more audio data, it also results in a larger file size. This is the reason it has become so common to compress audio files — so you can fit more music files on your device.
Lossy vs Lossless
With audio file formats, there are two types of audio quality: lossless and lossy. Lossless formats retain all of the original audio data. Typically, these are large, uncompressed files with lots of information and very high bitrates. There are also some compressed audio formats that retain lossless audio quality (more on that in a moment).
Lossy formats are compressed files that lose audio quality as the bitrate and file size is reduced. The files are made smaller by removing audio data that exists beyond a certain frequency range (such as hums and feedback) and by reducing the quality of certain sounds (such as cymbals and high-hats). The higher the bitrate, the more of the original data that is retained. This means that with a higher bitrate, you'll have higher audio quality but a larger file size.
To make this easier to understand, we've made a couple of very basic diagrams to help you visualize the difference between lossy and lossless compression. Referring to the diagrams below, think of an audio file as a stack of different colored blocks. The different colors in the diagram below represent different audio frequency ranges.
Lossy Compression
Referencing the diagram below, you'll see that lossy compression removes the less audible frequency ranges (represented by yellow and green blocks) to make the overall file smaller. The audio data that is read back in by your music player no longer processes the deleted data. This results in a smaller file size at the cost of audio quality.
The main benefit of lossy compression is file size. Audio CDs use a lossless format for very accurate sound reproduction. A typical audio CD containing 9 songs might use up 500 megabytes of disk space. But those same 9 songs might only use up 50 megabytes once compressed.
Lossless Compression
With lossless compression, instead of deleting extra blocks, the redundant blocks are removed and replaced with instructions. For example: In the chart below, you'll see that once our audio file is compressed into a lossless format, two blocks are now represented by one block with the number two. Three blocks are represented by one block with the number three, and so on. When your music player reads the compressed file, it processes the instructions and rebuilds the original file with no loss of the original audio data. It gives you a much smaller file size while retaining the highest possible audio quality.
The benefit of lossless compression is this retention of audio quality and a reduced file size. The downside is that the file sizes are still larger than with lossy compression, and not all music players support lossless file formats.
FLAC (Lossless)
FLAC is an acronym for Free Lossless Audio Codec and is a lossless audio format that allows reduced file size with no cost to audio quality. FLAC files are compressed in a way that does not reduce the audio quality, making it one of the best formats available for archiving your music. This compression makes it possible to reduce the file size by up to 60% while retaining all of the raw audio data.
FLAC was introduced in 2001 as an open-source file type and has grown to one of the most popular audio file formats today. Because it is one of the most popular lossless formats, most modern devices support FLAC playback. Unlike WAV format (the most popular lossless format), FLAC files also retain information tags — storing artist and album information.
WMA (Lossy)
The WMA format is a lossy audio file — similar to MP3. WMA is an acronym for Windows Media Audio and was first released in 1999 by Microsoft for use with their Windows Media Player. The file format has evolved since its initial launch, but has continually retained the WMA file extension.
The WMA format is similar to the MP3 format and compresses the audio file in a similar way that leads to a reduction in file size at the cost of reduced audio quality. Because this format is not as widely supported as MP3, there is no advantage to choosing this file type.
MP3 (Lossy)
MP3 is an acronym for MPEG Layer 3. The MP3 format was originally released all the way back in 1993, and has been steadily gaining in popularity ever since the dot com boom of the 1990s. Today, the MP3 format has become synonymous with digital music, and has become the standard for nearly every digital audio player the world — so much that nearly all digital music players are referred to as MP3 players.
MP3 is a lossy format originally developed to create a listenable audio file that doesn't use up much disk space. This file-size compression is achieved by cutting out all of the audio data that exists beyond the hearing range of the average person and by reducing the quality of sounds that are more hidden in the mix. The result is a listenable file with a small file size. The quality of an MP3 file can vary considerably depending on bitrate and audio export settings.
So which format is right for you? Well, that depends. Generally for listening to music on the run, a high-bitrate MP3 would be more than sufficient. MP3s are supported by nearly every digital music player in the world, and the sound-quality can be quite high. The small file size makes MP3s a perfect choice for filling up a thumb drive or portable music player. MP3s also work great in most modern car stereos — including your RetroSound® RetroRadio™.
FLAC is another fantastic format that is quickly gaining in popularity. You can archive all your music into FLAC format to keep the audio quality of the original file while saving space on your device. Not all devices can read FLAC files, but your RetroSound® RetroRadio™ can. The high audio quality and small file size makes FLAC a perfect choice for audiophiles.