I have always had a bit of a bee in my bonnet about people listening to music at a lower quality than they need to.
That probably comes from spending so much of my life working as an audio engineer. The more time you spend critically listening to sound, the more you begin to notice the small details that make up a recording.
At the same time, sound quality is subjective. How you listen to music and how you enjoy it is entirely up to you. If you love how something sounds, that is ultimately what matters. Music should always be enjoyed first.
My personal mission, however, has always been to encourage people to listen to music at the highest practical quality available.
So rather than simply saying that WAV files are better than MP3s, let's look at what is actually happening to the audio.
The basic difference:
Can You Actually Hear The Difference?
This is where the debate becomes interesting. A well-encoded 320 kbps MP3 can sound extremely good, and on some playback systems the difference between it and the original lossless file can be very difficult to hear.
However, in a controlled studio environment on revealing monitoring, I can hear differences between compressed MP3 files and their lossless WAV equivalents.
We have even had this debate inside our own studio. My studio partner initially wasn't convinced that the difference was something he could reliably hear. Through repeated listening and ear training, he gradually began recognising some of the same characteristics I was hearing.
That is an important point: critical listening is a skill. Once you understand what compression artefacts sound like and where to listen for them, they can become much easier to identify.
WAV vs MP3: The Important Facts
Lossless vs Lossy
Uncompressed PCM WAV audio preserves the audio samples contained in the source file. MP3 uses lossy compression, meaning some information is deliberately discarded to reduce the size of the file.
Much Less Data
Standard 44.1 kHz / 16-bit stereo PCM audio contains approximately 1,411 kbps of audio data. A 320 kbps MP3 represents the music using considerably less data.
MP3 Removes Information
MP3 compression uses psychoacoustic models to identify information that is considered less perceptible to human hearing. Some of that information can then be removed or represented less accurately to achieve a smaller file.
High Frequencies Can Be Reduced
MP3 encoders may reduce or remove information towards the upper end of the frequency spectrum. The exact behaviour depends on the encoder, bitrate and settings rather than there being one universal MP3 cut-off frequency.
Compression Can Create Artefacts
Lossy encoding can introduce audible artefacts including changes to transients, high frequencies, ambience and stereo information. At high bitrates these effects can be subtle, but the encoded signal is still not identical to the original.
Repeated Encoding Makes It Worse
Repeatedly encoding lossy audio can progressively degrade the signal. Converting an MP3 into another MP3 does not restore the missing information; another lossy encoding stage is simply being applied.
WAV Is Better For Processing
When audio is going to be EQ'd, compressed, limited, time-stretched or otherwise processed, starting with a lossless source gives the engineer the most complete version of the audio to work with.
Storage Is No Longer The Issue
MP3 became successful partly because dramatically smaller files were extremely useful when internet speeds and storage capacity were limited. Today, lossless audio is far easier to store, transfer and stream.
Why We Prefer WAV
Mixing & Mastering
If an engineer is mastering your music, there is very little reason to send them an MP3 when the original lossless mix is available. Once information has been removed by lossy compression, mastering cannot put that information back.
Mid / Side Processing
Lossy coding can alter stereo information and ambience. Those differences can become more noticeable when processing the Mid and Side components independently, which is another reason mastering should begin with the original lossless mix.
Time-Stretching & Master Tempo
Processes such as time-stretching, pitch manipulation and DJ Master Tempo algorithms place additional demands on the audio. Existing compression artefacts can become easier to notice after this type of processing.
DJ Playback
Where equipment and storage allow it, lossless files provide DJs with the highest-quality source before the audio passes through mixers, processing, PA systems and any subsequent recording or broadcasting.
Future Editing
A lossless master is far more useful if you later need to create radio edits, extended versions, clean edits, instrumental versions or other derivatives of the finished track.
Long-Term Archiving
Your master should be treated as an archive asset. Keeping a lossless version means you retain the highest-quality practical copy rather than permanently storing only a compressed listening version.
The Problem With Compressing An Already Compressed File
Imagine a DJ set made entirely from MP3 files. Those tracks have already passed through one lossy encoding process.
If the complete DJ set is then recorded and uploaded as another MP3, the finished recording passes through another lossy encoding stage. The second encode does not simply preserve the first MP3 — the encoder analyses and compresses the audio again.
Compare that with starting with lossless WAV files and only creating an MP3 at the final distribution stage. You minimise the number of lossy generations and preserve more of the original audio throughout the production chain.
This is one of the simplest principles to follow: keep the signal lossless for as long as possible and only create compressed versions when you actually need them.
So, Should You Stop Using MP3?
MP3 isn't useless. It is an incredibly successful format that solved a genuine problem and helped make digital music practical at a time when bandwidth and storage were far more limited.
A properly encoded 320 kbps MP3 can also sound extremely good, particularly in normal listening conditions.
But that doesn't make it the ideal master format.
If you have the choice between keeping your finished music as a lossless WAV or permanently reducing it to a lossy MP3, I see very little reason not to keep the WAV.
Use lossless audio for recording, production, mixing, mastering, DJ libraries where practical, distribution masters and long-term archiving. Create an MP3 when you specifically need a smaller, convenient listening copy.
Most importantly, enjoy the music. Sound quality should enhance that experience rather than get in the way of it.