MP3 128 kbps vs 320 kbps [The NO B.S. Guide!]

What is an MP3?

If you’re in the business of audio recording, it’s important to know the difference between MP3 128kbps and 320kbps.

Knowing the difference between audio qualities is essential if you are recording music; it means the difference between putting out a nice sounding record and a bad sounding one!

To start, it’s important to understand exactly what an MP3 is, in case you don’t already.

If you recall from a previous article of ours, we talked about how MP3 was formerly known as MPEG-1 Audio Layer III or MPEG-2 Audio Layer III, and it refers to a coding format for digital audio.

It was developed largely by the Fraunhofer Society in Germany, with support from other digital scientists from the United States.

It was originally defined as the third format of the MPEG-1 standard, and it was adopted further, giving it defined additional bit-rates and support for more audio channels.

The MP3 file as we know is used for audio compression. It uses lossy data-compression to encode data using inexact approximations and the partial discarding of data.

This lets a large reduction in file sizes when compared to uncompressed audio. 

With the combined power of a small size and acceptable fidelity, it let to a boom in the distribution of music over the internet in the late 1990s. Mp3 served to enable technology at the time when bandwidth and storage were at a premium.

MP3 compression works by reducing the accuracy of certain components of sound that are considered to be beyond the hearing capabilities of most humans.

The method is usually referred to as perceptual coding or as psychoacoustic modeling. The audio info that is left over is then recorded in a space efficient manner using special alogrithms. 

Compared to CD quality digital audio, MP3 compression can usually achieve a 75 to 95% reduction in size. In the early 200s, compact disc players increasingly adopted support for playback of MP3 files on data CDs.

What does kbps mean in music?

When we talk about kbps, we are talking about kilobits per second (kbps). Audio CD bitrate is always 1,411kbps, while the MP3 format can range from around 96 to 320kbps.

Streaming services like Spotify range from around 96 to 160kbps. While higher bitrates appeal to audiophiles, it’s not always better. 

The bitrate, or rather the average amount of data required per second of music, determines the audio resolution of an MP3.

Generally the higher the number of kilobits, the closer in sound quality the MP3 is to the original source. It also means the file size will be larger.

Many internet download sites are primarily occupied with coming up with better ways to give us faster downloads, which means keeping the MP3 files as small as possible.

128kbps MP3s are generally considered to be the lowest acceptable level of sound quality.

Uncompressed, Lossless, and Compressed Audio Files: What does it Mean?

Sound is made of waves, and the audio files we see when we’re recording are the representation of those waves.

The way those waves that we see are encoded in audio files through individual samples includes the waveform’s shape at a given moment and how far away it is from a zero point.

The zero point is silence, and audio files measure a sound’s distance from silence.

Just like how images can vary in quality and clarity, types of audio files will differ in how large they are, how much information they contain, and what role they fill.

While there are a few exceptions, uncompressed files will usually contain the most information and therefore have the highest bitrate.

Compressed lossy files usually have the least amount of information and therefore have a lower bitrate.

To make it a little easier:

Uncompressed files

The audio files are very large, and include all of the possible information that audio equipment can detect. Uncompressed file formats include WAV, AIFF, and PCM

Compressed lossless files

These file types are compressed but in a way that no info gets lost. They include FLAC, WMA, and ALAC. These files are larger than compressed and smaller than uncompressed files.

Compressed or lossy files

Generally the smallest types of file formats, compressed files remove some information that is not entirely essential. Popular lossy audio file formats include MP3 and AAC.

Finding the Right Bitrate

When you are starting a new audio project, it’s good to record the best quality you possibly can, with a high sample rate and bit depth. When producing audio, you need to keep in mind how your listener will be interacting with your audio.

Variable bit rate can become useful when looking at the amount of details needed, as it continuously changes bit rate throughout playback.

Usually when it comes to audio bitrate, size does actually matter. The more kilobits per second the greater quality of sound. For most general listening 320kbps is ideal.

Of course, CD-quality audio that stretches to 1,411kbps will sound better. Bit rates range from 96 to 320 kilobits per second.

Usually, for a good MP3, using a bit rate of 128kbps usually results in sound quality similar to what you would hear on the radio.

Many who are in the industry recommend people use a bitrate of 160kbps or higher if they want the MP3 file to have the same sound quality as a CD.

The best way to judge the quality of an audio file is to look at its bit rate. Keep in mind that this is relative to its original, not to its musical or engineering quality. Audio file bit rates are measured in thousands of bits per second.

As mentioned, higher bit rates are better, so a 256kbps MP3 is better than a 128kbps file. If you want to improve MP3 sound quality, you can normalize the audio.

There are lots of ways to do this: you can use audio editing software, making sure to always use the best quality audio, and just generally investing in better equipment.

The absolute lowest MP3 bitrate you should consider for your music is 128kbps. For a while this was the standard and referred to as being CD quality, but it’s changed quite a bit since then.

This bitrate will allow you to get a lot more music on an MP3 player, but you would probably be sacrificing a great deal of audio quality as a result of that.

The Importance of a Higher kbps

Despite the overall tone and character of the music being preserved, the greater the compression, the more sonic details are lost.

Extremely high and low frequencies usually get discarded quickly with just the slightest amount of compression.

Although some of these frequencies are considered inaudible, they still serve a purpose by reinforcing harmonic frequencies that act as a sort of shade in the sound, giving the music much more fullness and presence. 

Further compression can diminish the differences between loud and soft passages, and could decrease dramatic impact in the music you’re making.

Extreme compression, think something like 64kbps and lower, can completely flatten the sound, resulting in something harsh and muddy. Depending on what you’re going for, that may not be exactly what you want.

In contrast, MP3 files of 192kbps, 256kbps or greater preserve most of the sonic information of the original WAV file.

Acoustic instruments tend to keep their more natural warmth at these resolutions, and electronic instruments sound much fuller while still retaining that punch they usually have.

So the question you may have now is how can you make sure the MP3s you’re importing onto your music library are at the best sound quality for you? It very much depends on the source, but you can have some control over the process.

When you’re importing music from CDs, change the default settings of your PC’s media player. Almost all of these programs let you adjust the MP3 resolution from the standard 128kbps up to at least 320kbps.

Many let you customize the setting by typing in your own number. When you purchase music online, most sites offer songs at 192kbps. Some sites, however, offer tracks at a higher resolution.

Many of these higher-resolution tracks also come without copy protection, giving you the added advantage of enjoying your purchases in more ways on more players. Many of these tracks are offered at 256kbps.

If you’re downloading music from other sources- things like band websites, or podcast directories- most sources like these offer the MP3s at 128kbps.

Try downloading other formats that your player supports, and you may find one that sounds better to you than the others.

What if MP3 is not an Option?

Sometimes you aren’t offered the choice of MP3s with different levels of compression.  Instead you might have the choice of different formats instead.

Every codec has its own algorithms to determine what to discard, and so the same song saved in different formats can vary slightly in sound. Some people find they like a particular codec and prefer it over MP3

There are also formats that retain all the information of the original files, and just store them more efficiently in a slightly smaller space. If you recall earlier in the article, these are lossless codecs. 

Another great option if MP3 won’t work for you is FLAC. This kind of audio file offers a few different benefits while still having a good audio quality.

Audio data suffers no loss of information as the integrity of the audio data is insured by storing an MDS signature in the file heads. Lots of electronic devices are compatible with FLAC, from simple players to stereo equipment.

FLAC files also tend to be great for using in editing applications and software, and it supports fast sample-accurate seeking.

Additionally, keep in mind that having music in lossless and keeping it in lossless means that you can transcode the music as many times as you’d like without losing the quality of the audio file.

If there is ever a day when the world decides to not use MP3 files anymore, your FLAC files will still be there!

It’s up to You to Decide!

Back to our original question, is 128kbps better or worse than 320kbps? As some people will mention, it isn’t really about the best bitrate.

In fact, there is no real best bitrate, merely the right bitrate. The right bitrate will depend heavily on the kind of music you’re making.

In general, 128kbps MP3 files will be smaller in size, will remove more of the higher frequencies, and have slightly more audible compression artifacts.

If you think about the music you want to make, you can decide for yourself if that’s a good or bad thing.

In general, we’ve established that a higher kbps is better in sound quality than a lower one, and that also tends to sacrifice space saving, giving us a bigger audio file.

Keep in mind that you can always compress a large file into a smaller one, but you can’t restore the resulting file back to its original form. The information lost in the compression process is permanent.

It’s generally best to choose the highest resolution when you first import a track. A 128kbps file can’t be bumped up to 256 kbps any more than a low resolution photo can be blown up to a poster sized print.

The most important thing to remember when you’re changing settings to improve sound quality is that at the end of the day, your ears will be the final judges.

Some people can distinguish between a 256 kbps and a 192 kbps MP3, but to regular humans like me and you there isn’t really an appreciable difference between a 128 kbps file and the original CD track.

It is up to you to determine the ideal MP3 resolution for the music you listen to or the music you make. Maybe you don’t even want to use MP3 and that’s ok.

But remember to try giving the higher resolutions a fair chance. You might be really surprised to hear what you’ve been missing!