Behind every song is a recording process that transforms live instruments and sounds into to digital audio files we can enjoy in our headphones, in the car, or on the club speakers. While you might have a strong background when it comes to making music, knowing how to preserve your sound quality across audio formats is essential to connecting with your listeners.
Below, we'll help you navigate everything you need to know about audio bitrate, how to maintain top audio quality, and decode some of the lingo around audio data. This way, you can put your best foot forward on streaming services and beyond.
It's worth noting that bit rate can refer to any digital format, so you'll often hear it discussed within the context of video quality. In this guide, we will be focusing on audio bitrate specifically so that you can nail down the best audio file format settings for your specific needs.
What is Audio Bitrate?
By definition, audio bitrate is a measurement of the amount of data transmitted or processed per second. This parameter heavily plays into the overall size of an audio file, and is measured by "bits per second" or "kilobits per second" abbreviated as bps and kbps respectively.
If you're having trouble grasping the concept, it might be helpful to think of audio bitrate, or individual audio "bits" as auditory pixels - the more pixels a photo has, the more clear the image is. However, the more pixels are, the larger the file size.
The more audio bitrate you have, the higher quality audio you'll have, but this also comes with larger file formats. Determining audio bitrate size and quality is key to packaging your songs into common containers like WAV, MP3, and AIFF files.
Audio bitrate, bit depth, and sample rate are all terms used to describe similar aspects of audio quality, but they are all inherently different. Their differences can be summarized in this video by Dr. David Macdonald:
Bitrate can also be thought of how much data is being played at any given moment. Have you ever listened to Spotify when you have slower internet connections? You might have noticed that the sound quality of your song appears to be reduced. This may be because the song in question is playing at a slower bit rate in order to compensate for the poor connection.
Once you return to an area with a stronger internet connection, your phone might be able to handle streaming at a higher bitrate, causing you to experience better sound quality since you're receiving more of the original auditory data.
How Does Audio Bit Depth Work?
Bitrate and bit depth are similar, but they ultimately measure different aspects as it pertains to audio quality. Bit depth measures how many bits represent detail within the amplitude of a sample or audio file. It's also known as resolution or sample depth, and includes commonly held formats like 16-bit, 24-bit, and 32-bit. Audio bit depth is in part a measure of dynamics or dynamic range-- the higher the bit depth, the more likely you are to hear the nuances between the peaks and valleys of a song or sample.
Audio bitrate is simply a measure of how much data is used overall within a sample or audio file. This measurement tends to be more variable, not at a set point. Bit depth is how detailed the information in each bit is, whereas bitrate measures how many bits there are in total. Higher bitrates and higher bit depths both equate to larger file size.
Sample Rate and Bit Depth Compared
Sample rate is the rate at which bits are captured, the higher the sample rate, the more bits you'll capture, creating a higher bitrate and ultimately a more detailed, high-quality audio file. Bit depth refers to the individual points of data, specifically how detailed each bit is.
What is PCM in Audio?
When talking about bitrate, bit depth, and sample rate, you're likely to come across the term "PCM" which stands for pulse code modulation. PCM refers to the way in which analog sound gets converted into digital audio. This is the initial format that's created before a PCM audio file is transformed into high quality wav files, advanced audio coding (AAC) files, AIFF files alongside compressed audio formats like MP3s.
Lossy Audio vs Lossless Audio Formats
Lossy and lossless audio formats are both optimized for different things. Loosely speaking, lossy audio formats prioritize convenience over sound quality, creating compressed audio formats that make it easy to stream or free up storage space. Common lossy formats include OGG, MP3, and AAC.
Lossy audio formats are designed to sacrifice bits of data that hold less value or are less noticeable when it comes to optimization for the human ear.
By contrast, lossless audio is designed to provide the best audio format experience as possible, even if that means working with a much larger file size. These files are compressed as little as possible, utilizing advanced algorithms to reconstruct a digital audio file with extreme accuracy. Lossless audio formats include WAV, ALAC (Apple Lossless Audio Codec for Apple Music), and FLAC (Free Lossless Audio Codec).
You can hear the difference in this video:
Lossless formats preserve the audio quality as much as possible, so in many cases, they won't have variable bitrates. However, factors like bit depth will affect the overall quality of the lossless audio formats.
Determining Bitrate by Audio File
Each audio file format has its own respective audio bitrates that should be taken into consideration throughout the audio recording process:
Wav Audio Files
Wav files are one of the lossless formats, meaning that the file is built to prioritize audio quality accuracy over-optimizing storage space. As a lossless format, the original audio quality is preserved though streaming services may slow bitrate based on a listener's internet connection or preferences. Generally speaking, Wav files should have a bit depth of 24 and a sample rate of 44.1kHz.
CD Audio Files
Uncompressed CD audio utilizes uncompressed PCM audio, typically with a 16 bit depth and sample rate of 44.1kHz. As with other lossless formats like WAV, audio CDs bitrate is preserved from the original audio file.
MP3 Audio Files
MP3s, also known as MPEG Audio Layer III, is one of the most popular lossy audio formats. You can set a bitrate for MP3 files to optimize for quick playback on streaming services and otherwise. Decent quality bitrates for MP3 files fall between 192kbps to 256kbps.
Great quality MP3s tend to have a bitrate between 256kbps to 320kbps. You can also use variable audio bitrate, or VBR. This bitrate processing technique sets a different bitrate throughout the course of an MP3. The idea is that you preserve as much storage/data space as possible while still providing enough room for the more nuanced parts of a song to shine.
What Bitrate Should I Use?
When determining the right bitrate for the job, you'll want to consider the intended output and desired effect on the listener. Generally speaking, when optimizing for quality audio you'll want to opt for a higher audio bitrate between between 256Kbps and 320Kbps if possible. However, a higher bitrate might become more difficult to play since it has a higher file size, which isn't built for streaming services.
For instance, Spotify's streaming quality for free users is 128Kbps. Premium users have a bitrate of bitrate is 256Kbps or the option to toggle to the highest quality audio at 320kbps. By comparison, Apple Music provides a maximum values of 256 Kbps. Apple Music provides 16 or 24 bit depth, and Spotify only provides 16 bit depth.
In most cases, you'll want to export a song for streaming services with 256Kbps with 24 bit depth at 44.1Hz in WAV format.
As discussed above, there are different standards for specialized use cases like creating CD quality audio or optimizing for MP3s. Follow the standard parameters per your audio recordings' use case. It's a good idea to take a listen to songs at various bitrates yourself to have a stronger understanding of how audio birate affects MP3 and WAV files.
Hear the difference in bitrate using this experiment by creator TechDamis. Use headphones for best results:
Don't forget that preserving your audio file formats isn't just important during the exporting process. When recording or using audio equipment, it's a good idea to record at a higher bitrate to ensure that you don't lose quality across the music production process. Remember that every layer builds onto itself. You cannot transform a low bitrate recording into a higher quality recording, but you can compress a higher bitrate recording.
Recording at a higher bitrate (assuming you have the storage space and it doesn't slow down your digital audio workstation) is a good rule of thumb.
Audio Bitrate FAQ
Use these commonly asked questions and answers to help you bake better sound quality into your music:
Is a higher audio bitrate better?
Having a higher audio birtrate generally means that you'll have better audio quality. However, this also comes at the expense of larger file formats, so it may be challenging to stream audio with such a high bitrate. Some playback devices like headphones and speakers may not be able to reproduce a larger bitrate to a T, so in some cases, a higher bitrate might not be worth it.
How do I check an audio file's sample rate and bit depth?
In most cases, you should be able to right-click an audio file and select "information", "properties" or something similar to check a file's sample rate and bit depth. There are also several online tools that can be used to check an audio file's resolution, like Maztr's free audio analyzer .
Is 320kbps good audio quality?
320 kbps is considered good sound quality. This bit depth is often used for common audio format outputs like AAC or MP3. While it's often used for compressed sound, this bit rate still strikes a good balance between file size and quality audio.
What is the difference between 24 bit and 320 kbps?
24 bit is a measure of bit depth whereas 320 kbps speaks to audio bitrate. Both of these values are associated with fairly good audio quality, but it's important to note that there's a difference between bitrate and bit depth though they have similar names.
What happens if audio bitrate is too high?
If an audio's bitrate is too high for the format it was exported for, it can make it more challenging to enjoy on digital music platforms, since more data presumably takes longer to load. It's also key to note that audio streaming platforms tend to compress all audio files regardless, so unless you're using an output built for uncompressed audio formats, you could have diminishing returns by the time the piece gets to the listener.
Audio bitrate is one of those important aspects to understand if you're actively releasing music. Hopefully, this guide makes it easier for you to understand the ins and outs of producing high-quality audio with an audio bitrate that's built for your desired output. Have fun making better use of your audio samples and tracking down the best audio bitrate for your needs.