Maybe you're a musician who has done the hard work of studying audio theory, writing or arranging your music, practicing it, recording it, and now you want to present it to the world. What is the best file format for your finished product? Or you could be a music lover looking for the best way to permanently store all your music. You might already have the music in some kind of digital form, or you might be ripping it from CDs or vinyl records. What audio formats will optimize your collection? Choosing the right file format matters. For one thing, the format you use will affect the authenticity of the sound of the music. File formats also determine what kinds of devices will be able to play the music. In this guide, we will look at the different audio file formats that are available, what they offer you, and how to make the best use of them. But first, let's get an understanding of what digital audio files are.
So, what is the best audio file format for you?
To choose what is the best audio file format to use, you need to look at your purposes for your files. Here are some common uses, with suggestions about the best audio formats for each one:- Are you burning your music files onto a CD? For that, uncompressed (WAV or AIFF) file formats are the standard. You want to start with the highest quality file you can when you burn music.
- Are you archiving your music? A lossless compressed format like FLAC or ALAC will allow you to store your files as efficiently as possible without losing audio quality.
- Are you digitizing music from vinyl? Again, a lossless compressed format will give you the best sound quality while allowing you to store more files.
- Are you looking for the ultimate listening experience? Lossless compressed or uncompressed formats provide the best listening if you have a player that is compatible with the format. To get the most out of listening to lossless recordings, you want to listen with high-quality equipment that will deliver the full range of sound from your recording.
- Are you sharing your music with the public? You will need to use lossy file formats because of their small size and device compatibility. Just about any device will play an MP3 file.
Digital audio files
When music is recorded, the recording device takes the soundwaves from the air and translates them into a physical form. In analog recording, the recording device stores the music as one continuous audio signal on a physical medium like a vinyl record or a tape. In digital recording, the soundwaves are turned into a series of many little digital signals. These digital signals are like tiny bits of sound, similar to the way that a digital camera turns images into millions of little pixels. This digital data can never be exactly like the waveform from the original sounds in the air, just like you can't exactly duplicate a curved image through little square pixels. But the more tiny signals the computer creates, the closer it will be to the original waveforms. With enough digital signals, you eventually reach the point where the human ear can't really tell the difference between the digital sound and live music. Again, it's just like with digital pictures -- the more pixels per inch, the more life-like the picture will look, to the point where the eye can't tell that the digital picture is different from a real physical image. More density of signal data means more realistic sound. There are many different types of audio file formats that use different densities of signal data. This signal density determines the sound quality that a file format will have. If you are recording music on a computer, the computer will probably store the audio in a format that preserves as much sound quality as possible. If you are converting analog recordings to digital, you may be given a choice between a higher-quality or lower-quality format. Let's take a look at the different categories of formats, starting with the ones of the highest quality.Lossless audio formats
A lossless audio file format is a format that captures the maximum amount of signal data possible. Therefore, it will be as close to the sound of the “raw” music as you can get. We call these formats "lossless" because there is no loss of sound quality. Lossless format files give the most authentic, "like you're right there in the room", sound quality that is possible from a digital recording. This makes them very attractive in terms of music quality. But because they contain such a huge number of digital signals, the files are very large. Some of the lossless formats can be compressed somewhat in order to decrease the file size; others do not allow any compression.Uncompressed lossless formats
The most common uncompressed audio file formats are WAV and AIFF. More details on these uncompressed formats can be found below.PCM
PCM is a file format called Pulse-Code Modulation. It gives a digital map of "pulses" at which the sound has been sampled and recorded. This method gives a close sound, not far from the original source. The PCM format of files is usually used within CDs and DVDs. A subtype is called LPCM which means Linear Pulse-Code Modulation. This simply uses intervals with linear measurements for the samples. Most PCM sound uses LPCM.WAV
WAV (which stands for "Wavefile Audio File Format") is a format that was developed by IBM and Microsoft. This is the standard file format for uncompressed audio on the Windows operating system. In the past, some Macs would not play WAV files, but now both Windows and iOS devices play both formats.AIFF
AIFF (which stands for "Audio Interchange File Format") was developed by Apple and it is the standard uncompressed format on iOS devices. Though it is commonly used on Apple devices, AIFF files aren't the most efficient with space. The quality is similar to CD, but the files are bigger. There's no real advantage to using them over the other lossless formats.Using lossless audio
Here are the pros and cons of using uncompressed lossless audio formats. Pros:- You get top-level sound quality.
- If you're starting from a digital recording, you won't need to do any conversion because the uncompressed format is the way the computer originally stored your music
- The large size of uncompressed music files limits their usability. You may not be able to store a large number of uncompressed files on your computer, and they are difficult to download or distribute. (If you have ever tried to email a WAV file, you know what we mean!).
Compressed lossless formats
Compressed lossless file formats take all the audio information from the recording and store it in a different style that takes less space, but all the digital signals are still there. As a result, the files are smaller, but they're still lossless because there is no change to the waveform or the sound quality of the recording. Because compressed files are smaller, they are easier to store and transfer and are compatible with more >devices. Common compressed lossless audio formats include FLAC and ALAC.- FLAC format can be either compressed or uncompressed. The uncompressed form is just as big as a WAV or AIFF file. If you're converting an uncompressed file to FLAC format, it will be saved in uncompressed FLAC format unless you choose the compression option. FLAC stands for "Free Lossless Audio Codec". FLAC is an open-source format that many devices recognize.
- In ALAC format, compression is the only option. ALAC stands for "Apple Lossless Audio Codec". Apple originally created ALAC, but they have released it to be open-source. ALAC files are put in a container called MPEG-4 format.
- You still get the best possible sound quality.
- Compressed files are easier to store and transfer.
- Both FLAC and ALAC formats are compatible with a variety of players.
- These compressed files are still too large for some uses. Many small devices like phones and tablets cannot download them.
- A lot of music players do not play these formats.
Lossy file formats
Due to the lossless huge file size, even in its compressed version, many times a more aggressive type of conversion is needed. This sacrifices quality on order to achieve a small file size. The files generated from this kind of conversion are called Lossy. It's important to state that the parts lost during this process are inside the human audible spectrum range, meaning converting to lossy loses audible information. (as opposed to what many think, that it only affects frequency response in ultra-high and ultra-low frequencies). In other words, it's possible to hear the difference between a lossy and a lossless file. Of course, there is a wide variety of lossy formats and there are highly trained years, but it's undeniable that the losses are in a range which is perfectly audible by a normal human being. Basically speaking, you are losing information bits from the file. To use a visual analogy, think about a photograph on a screen, if you start to lose pixels then the quality is lower. This is what is happening with Lossy audio. The most common lossy audio format is our old friend the MP3 format. Another common lossy format is Apple’s AAC format. An MP3 file can be as small as 2% the size of a WAV file of the same recording. Pros and cons of the lossy formats? Pros:- These smaller, lossy files are much easier to download, store, and share. They're also popular among streaming services as they will use less data.
- The sound is good enough for many purposes. Often, if you're listening on poor quality speakers or headphones, you wouldn't be able to tell the difference.
- Lossy files do not have the full quality of sound that lossless formats do.
Comparing file sizes of different audio formats
A member of our staff took a recording of one song and stored it in five different audio file formats. In this graphic, you can see the difference in size between the WAV and AIFF files, the compressed FLAC and ALAC (MPEG-4) files, and the MP3 file. Clearly, there would be many instances where the lossy MP3 file can do the job that the bigger lossless files can't. These are the different types of audio file formats. Next, let's talk about best practices for converting one format to another.Transcoding
Transcoding is the process of converting a digital file from one format to another. This is how you create a compressed audio file from the original uncompressed file. Most likely, the recording software on your computer already has built-in functions that will convert your music into compressed formats. But if not, or if you want a particular audio format that your software doesn't offer, there are websites that will do transcoding online. You always want to be sure that you are converting the right way to get the right results. If not, you might as well not be using higher quality sample formats and audio codecs in the first instance. Here is how to optimize your transcoding efforts.Good vs. bad transcoding
Here's how to make sure that your transcoding is working for you and not working against you. You understand now what the different audio file formats are, and that is the first step. You know which formats lose sound quality and why. The next thing you need to understand is that when you remove sound quality from a file, that lost quality is gone forever. In other words, if you transcode something into a lossy format, you do not want to take the lossy file and try to convert it back to a lossless format. You won't get the lost signals back!The types of conversions that can be helpful are:
- From lossless to lossless: Taking a lossless file format like a WAV/AIFF and converting it to another lossless format like a FLAC or ALAC file;
- From lossless to lossy: Taking a lossless file format and converting it to an MP3 or AAC. Going from a lossless format to a lossy format is called downsampling.
The type of conversion that will not do any good is:
- From lossy to lossless: Don’t take an MP3 and try to convert it back to a FLAC or WAV format. Going from a lossy format to a lossless one is called upsampling, and it will not accomplish anything. An upsampling conversion will take the data from the MP3 and space it out bigger, but you won't get back the digital signals that were removed to make the MP3 in the first place. Therefore, you will end up with a big file, but it won’t sound any better than the MP3 did.
- From lossy of a certain quality to a lossy of the same quality: Re-doing a transcode only results in more losses. Do not convertwith the same codec/transcode twice!
- From a lower quality lossy to a higher quality lossy: That's also upsampling. Quality lost is forever lost. Converting to a higher spec won't make the final audio better. The source file must always be of a higher quality than the resulting file's quality.
Music production and audio files - the golden rules
If you are looking to learn about music file formats because of your ambitions as a producer, there are some rules to follow! A detailed understanding of files helps, but there are some basic rules that can eliminate errors.- Always record in a lossless format. The industry standard is WAV. We recommend using WAV for pretty much everything until it is time to mix down a finished piece of music or recording. At this point, you might decide to use different file formats.
- Don't reduce file sizes to send audio during production. Let's say you want to send a guitar recording to a friend so they can make edits or run it through their effects and send it back. Don't degrade the audio or change to a lossy format in order to send more easily. It can be tempting due to the file sizes, but ultimately it isn't worth it. Once you've lowered the quality and lost the information bits, there's no going back.
- Work with source material in lossless formats wherever possible. By "source material" we mean things like individual drum samples you may wish to add, or samples you have downloaded from the internet or ripped from vinyl. We live in a sampling culture when it comes to music production, but there are some low-quality files out there. A kick drum sampled in WAV will be better than the same kick drum as an MP3 file.
- Understand the other aspects of audio files. One WAV file can still be lower quality than another. Learn about kbps and 16-bit vs 24-bit audio. These settings play an important part in the audio quality as well as the file format. Many audio software options let you set the kbps of your files or recordings.