With the popularization of music streaming services, audio quality has become a crucial factor for the user experience.
Did you know that this experience is primarily affected by the audio format used in the streams?
In this post, we will explain the difference between two widely popular formats: AAC and MP3. We will discuss the key differences, including audio quality, bit rate, compatibility, and other important factors that affect the streaming user experience.
Enjoy reading to learn a bit about the history of MP3 and AAC.
The history of the MP3 audio compression format is fascinating and begins in the early 1980s when the first digital music storage devices started appearing on the market.
At that time, most digital audio files were large and took up a lot of disk space, making it difficult to store and share them with others.
It was in 1987 that a group of researchers from the Fraunhofer Institute for Integrated Circuits in Germany began developing a digital audio compression algorithm that could reduce the size of audio files without compromising sound quality. The project was led by Karlheinz Brandenburg, who focused on the study of human audio perception.
The first version of the audio compression algorithm developed by the Fraunhofer Institute was called ISO/MPEG Audio Layer-1. The technology enabled audio file compression to about 1/10 of the original size, making it possible to store much more music on a single storage device.
However, the MPEG-1 Audio Layer-1 format did not achieve much success at the time because the sound quality was not as good as that of uncompressed digital audio formats. It was only in 1991 that the Fraunhofer Institute released the second version of the audio compression algorithm, called MPEG-1 Audio Layer-2.
The sound quality of MPEG-1 Audio Layer-2 was significantly better than that of MPEG-1 Audio Layer-1, but it was still not perfect. It was only in 1993 that the Fraunhofer Institute released the third version of the audio compression algorithm, called MPEG-1 Audio Layer-3, or MP3.
With the emergence of MP3, music became a digital file that could be easily streamed over the internet and stored on portable devices.
It quickly became the most popular audio compression format in the world. In 1994, the first MP3 song was created and shared on the internet, and in 1997, the first MP3 player was released by Diamond Multimedia.
The success of MP3 led to a true revolution in the music industry, making it possible to create audio streaming services.
However, MP3 was not the only digital audio format available at the time.
AAC was also developed by the Fraunhofer Institute, this time in 1997 as an alternative to MP3, with superior audio quality and more efficient compression.
AAC quickly became popular in the music industry, especially after the launch of Apple’s iTunes in 2001. iTunes was the first digital music service to adopt AAC as the standard format, and the popularity of the service helped drive the adoption of AAC in other music services.
In 2004, Apple released the iPod mini, which supported playback of AAC files and further popularized the format. AAC was also adopted by other digital audio devices such as smartphones, tablets, and high-quality sound systems.
In 2006, AAC was included as part of the MPEG-4 standard, along with other audio and video formats. This helped standardize the format and ensure its support by devices.
To this day, the MP3 and AAC formats continue to be widely used.
Now that you have learned part of the history of the development of these audio formats, let’s move on to the main differences between them.
MP3 and AAC use lossy data compression techniques to reduce the size of audio files without compromising sound quality. This technique involves removing audio information that is considered unimportant to the listener, such as sound frequencies that are not perceptible to the human ear. However, there are differences in how MP3 and AAC perform this compression.
MP3 uses a lossy data compression technique known as Discrete Cosine Transform (DCT) encoding. This technique divides the audio into time and frequency blocks and applies a mathematical transformation to reduce data redundancy. The result is an audio file with significantly smaller size but noticeable loss in audio quality.
On the other hand, AAC uses a lossy data compression technique known as Discrete Fourier Transform (DFT) encoding. This technique divides the audio into frequency bands and applies a mathematical transformation to eliminate data redundancy. It then employs a more advanced technique called Spectral Band Replication (SBR), which allows the lower frequencies of the audio to be preserved in a high-quality format while compressing the higher frequencies into a lower-quality format.
This more efficient compression technique allows AAC to offer superior audio quality compared to MP3, even at lower bit rates.
Bit rate is a measure of the amount of data that is transmitted or stored in a given amount of time. In the context of audio compression, bit rate refers to the amount of data used to store one second of audio. The higher the bit rate, the higher the audio quality, but also the larger the file size.
Both MP3 and AAC support constant bit rate (CBR), but they also use variable bit rate (VBR) to optimize audio quality in different parts of the music without compromising sound quality.
When compared, AAC generally offers better audio quality at lower bit rates than MP3. This is possible due to the encoding technique used by AAC, which allows the lower frequencies of the audio to be preserved in a high-quality format while compressing the higher frequencies into a lower-quality format.
Another important factor to consider when choosing between MP3 and AAC is compatibility. It refers to the ability of an audio format to be played on different devices and platforms.
MP3 is a widely supported audio format and is compatible with most devices and platforms. This means that MP3 files can be easily played on smartphones, tablets, computers, and other audio devices.
AAC, on the other hand, is less compatible than MP3. While AAC is supported by many popular devices and platforms, not all audio devices support the AAC format. This can limit the ability to play AAC files on certain devices, which can be considered a drawback.
While both formats are designed to offer efficient audio compression without compromising sound quality, they differ from each other. In terms of audio quality, AAC is generally considered superior to MP3.
MP3 is an audio format that provides decent sound quality at higher bit rates. However, MP3 can experience sound quality issues at lower bit rates, especially in songs with many instruments and complex sounds.
This is because MP3 compression can remove important audio information in such situations. On the other hand, the AAC’s DFT compression technique is capable of preserving more audio information.
Additionally, AAC may also be able to compress high-frequency sounds better than MP3. This is because AAC can retain audio information in those frequencies more efficiently than MP3, which helps maintain the final sound quality.
However, it is important to note that the final sound quality depends on many factors, including the quality of the original audio and the chosen bit rate for compression.
Number of Channels
The MP3 streaming format supports up to two audio channels, commonly referred to as “stereo audio.” It allows a song to be heard in two channels, one for the left channel and another for the right channel, creating a sense of spatial sound. However, the MP3 format does not support multichannel formats such as 5.1 or 7.1, which are used in movies and videos with more complex audio mixes.
On the other hand, Advanced Audio Coding (AAC) can support up to 48 audio channels, including multichannel formats like 5.1 and 7.1.
Which format to use for online radio streaming?
If you’re unsure about which format to use for your online radio streaming, here are our recommendations!
BRLOGIC recommends its clients to use the AAC format for stereo streaming at bitrates up to 64kbps. In other words, if you’re streaming at 32kbps, 48kbps, or 64kbps, opt for AAC. In these situations, the audio quality using AAC tends to be superior to the same bitrate in MP3.
For bitrates of 96kbps, 128kbps, and 192kbps, or for mono streaming, we recommend MP3. In these situations, the difference in audio quality is imperceptible. Considering the fact that MP3 has greater compatibility with players and applications, it is more advantageous to use it.
As we have seen in this text, there are several differences between the AAC and MP3 audio formats, such as compression technique, sound quality, and compatibility.
Both formats have their advantages and disadvantages, and it is up to broadcasters to choose the format that best suits their needs.
BRLOGIC’s clients benefit from highly qualified support to make the best choice for each type of project.
Take a free test and discover all the benefits.