Last Updated on December 2, 2022 by Norvan Martin
There are a lot of questions about the AAC and MP3 320 audio encoding formats, how well they perform and which one is better. This article was written to help answer some of them and provide a bit of a guide towards deciding on which one of the two formats to use by comparing their performance, what advantages each has over the other, and what devices they are compatible with.
AAC is a superior codec to MP3 320 because AAC can both do a better job at the same bit rate, or an equivalent job at a slightly lower bit rate. This means AAC 320 is better than MP3 320, however you will likely not notice the difference. You may not even notice a difference between AAC 256 and MP3 320. However, MP3 320 is compatible with more devices.
You can check out other similar audio codec comparisons here:
Otherwise, continue reading further to understand the difference between AAC and MP3 320.
What Is AAC?
AAC stands for Advanced Audio Coding and is a digital sound storing format that was created to succeed the MP3 format.
It can encode sound to a higher quality (especially in audio files with lower bit rates) while retaining the same file size that MP3 would offer.
It was released in 1997, and jointly developed by the tech companies; Sony, Nokia, LG Electronics, NEC, Bell, Dolby, NTT Docomo, Panasonic, and Fraunhofer.
Please note that there are different formats of AAC including AAC-LC, HE-AAC and HE-AAC2. Check out our article on AAC vs AAC-LC vs HE-AAC vs HE-AAC2 to learn more.
What Is MP3 320?
MP3 320 is an MP3 (MPEG 2, Audio Layer 3) audio storage format that can encode sounds up to, but not more than 320 kilobits per second (kbps).
It means that 320kbps is the highest rate of information at which the encoder can store quality sound.
The sound accuracy drops beyond this point as the information rate increases. MP3 was invented by Karlheinz Brandenburg and initially released in 1991, with an update released in 1994.
Advantages of AAC Over MP3 320
AAC can encode higher quality sound than MP3 at the same bit rate: AAC was designed with such an algorithm that enables it to compress sound more effectively than MP3, and so offer sound as true to the source as possible.
AAC’s encoding algorithm is purely MDCT (Modified Discrete Cosine Transform), unlike MP3, which uses a hybrid combination of MDCT and FFT (Fast Fourier Transform).
You can however get better results with MP3 if you use V0. You can check out our guide on MP3 V0 vs MP3 320 to learn more.
Sound Quality At Lower Bit Rate
AAC can also encode practically equal quality sound at a lower bit rate than MP3: Due to its ability to compress sound more efficiently, AAC can compress equivalent sound quality to MP3 in smaller file sizes which gives it a huge advantage over MP3.
AAC does its best work with the smaller sizes in audio files: AAC encoding can retain audio quality in smaller files where sound distortion would occur with MP3.
AAC has a wider frequency range: Ranging from 8 kHz to 96 kHz, it can encode more precisely than MP3 with a frequency range of just 16 kHz to 48 kHz.
AAC can support more channels: MP3 can only sync 2 audio channels compared to AAC’s 48.
This gives it more flexibility and accuracy with sound encoding as well as the ability to work wonderfully with audio files recorded in multichannel settings.
MP3 in particular offers the ability to encode in stereo or joint stereo. Joint stereo allows you to combine both the left and right channels for a smaller size file. Check out our guide on stereo vs joint stereo to learn more.
Advantages of MP3 320 Over AAC
At Higher Bit Rates
MP3 320 is practically equal to AAC’s quality at higher bit rates: The difference in quality between MP3 and AAC is nearly imperceptible with an increase in bit rate.
The advantage of the AAC format is only perceptible at 198kbps or lower, which is not a very popular bit rate amongst audiophiles.
MP3 is compatible with a wider range of devices than AAC: AAC is mostly found on Apple devices being the preferred encoding format for Apple Music and iTunes while MP3 supports a whole range of devices including those with Android and Windows operating systems.
Though both formats can be used on any device regardless, MP3 is still the more widely preferred.
MP3 is more popular: Due to being older and more widely available, MP3 has a popularity advantage over AAC. It is currently the standard audio encoder for most digital sound systems.
128kbps AAC vs 320kbps MP3
It is a fact that AAC encodes audio files of high observable quality at low data rates. While MP3 is known to produce a pretty high sound quality at 320kbps, AAC can produce a surprisingly clear sound quality at 128kbps.
However, 320 MP3 is still significantly crisper than 128 AAC.
AAC 192 vs MP3 320
The sound produced by AAC at 192kbps is quite clear for that bit rate, however, the sound quality is still not as high as MP3 at 320kbps, although at this point, the sound quality disparity is not as wide as in 128 AAC.
Some would argue that 320kbps is obviously of a higher quality than 192kbps but considering the frequency range and encoding advantage the AAC format has over the MP3 format, it is not ridiculous to compare them at both levels.
256 AAC vs 320 MP3
The sound quality produced by both encoders at these two levels is practically similar. AAC can produce a more or less equivalent audio standard at lower bit rates than MP3 (and at 256, it tilts towards more) so it’s no surprise.
AAC generally does much better than MP3 at lower bit rates whereas MP3 would naturally begin to produce distortions.
AAC vs MP3 vs WAV
WAV (Waveform Audio File Format) offers the best audio quality of all audio encoding formats, but at a comparably large size for MP3 and AAC files.
While the MP3 format produces reasonably good quality sound, it can be said to be the least performing in this area compared to the other two, however, MP3 file sizes are much smaller.
The AAC format meets both sides halfway and is a great compromise between size and quality, being able to retain high-quality sound at lower data rates.
AAC vs MP3 File Size
At the same bit rate, MP3 files are found to be a little smaller than AAC files and AAC files have the higher quality, but because AAC can produce similar sound quality to MP3 at a lower bit rate, AAC files have the advantage of retaining compression quality.
M4A 256 vs MP3 320
M4A or MP4 (MPEG 4, Part 14) is a higher, more advanced audio encoding format than MP3.
In terms of quality, M4A has the higher hand without a doubt while MP3 has the advantage of device compatibility, being the preferred standard audio encoding format on a wider range of devices (including Android devices and devices with the Windows operating system).
Based on just encoding quality, 256kbps M4A will produce equal (or higher) quality sound to 320 MP3.
Having compared the two encoding formats at varying frequencies, as well as file sizes, hopefully, this article has been able to provide you with adequate useful information to aid you in deciding what format best works for you. If you are doing high-fidelity recording, then AAC is the superior codec. However, at higher bitrates (greater than or equal to 256kbps) the difference between AAC/MP3 is negligible. In addition, keep in mind that MP3 320 is compatible with a wider range of devices.
Norvan Martin is the founder of BoomSpeaker.com. He is a professional Electronics Engineer and is passionate about home theater systems and AV electronics. BoomSpeaker was created as an online hub to share his knowledge and experiences as it relates to home theaters and home audio electronics.