Why mp3s sound bad, and how to hear it

I hate mp3, and this post will tell you why.

DO NOT read this post if you have a large collection of mp3s, enjoy listening to them and can’t hear any problems with them, because it’ll ruin them for you !

There’s been plenty written on how mp3 works, and why lossy compression sounds worse than uncompressed audio in general. My aim here is to demonstrate how mp3 sounds bad, for all the people who keep telling me there’s no difference.

I’m going to give you clear guidelines and examples on what to listen for and the negative effects of mp3, but there’s no going back - once you can hear the problems, you’ll never stop hearing them.

This isn’t limited to audiophiles, or “golden ears”, by the way - in my opinion anyone can hear this stuff, with a few pointers.

So seriously, unless you’re prepared to start using FLAC or AAC (which means buying an iPod) - stop reading now !

Still here ? Good.

First, I need to make this clear - I have nothing against lossy audio or data compression in itself - I do most of my casual listening on an iPod, using 128kbps AAC files - they sound fine. Not as good as the original CDs, obviously, but OK. And yes, I’m well aware that AAC is just a more advanced version of mp3. But the fact is that mp3 has fundamental limitations - even at higher bitrates.

Next - I’m also a pragmatist. mp3 is a temporary phenomenon, just like AM radio, cassettes and CDs. In the long run, none of those have killed music, and neither will mp3, or lossy compression in general. So, why the rant ?

Because people keep saying mp3 sounds great, or “indistinguishable from CD” and it’s just not true.

mp3 isn’t good enough

It doesn’t matter what encoder you use, it doesn’t matter what settings you use or what pre-processing you apply - mp3 just doesn’t cut it. AAC and later, more sophisticated encoders use more advanced encoding methods, and sound better to varying degrees, but mp3 just FAILs.

How does it fail ? That depends a little on the encoder being used, but some of my own pet hates include:

mp3 sizzle - the artificial, unnatural swirling metallic noises that sound like someone’s added chime bars to everything, or there’s a mosquito buzzing in your ear. Some people actually say we prefer these noises in mp3s - I say bullshizzle !
Added distortion - Yet another side effect of the so-called Loudness Wars. mp3 encoders rarely include any headroom for the encoding process itself, so the added processing pushes the music even further over the limits, generating inter-sample peaks and adding even more distortion in the process
Flat, two-dimensional sound mp3 works by throwing away musical information that we supposedly can’t hear - up to 90% of the original information, at 128kbps. That means all the subtle, delicate stuff, like ambience, space and realism. So a lush, three-dimension original is reduced to a flat, cardboard replica of itself
Mushiness All but the very best mp3 encodes just sound fuzzy, muddled and - well, mushy !


Hear for yourself

Don’t take my word for it - here are some examples. First, a truly nasty 128kbps mp3 example, from a Deep Purple live album I mixed a while back:

(Before anyone jumps on me, I’ve heard even a 256 kbps mp3s sounding like this - I’ve just used a low quality version to make the point.)

If that doesn’t sound too bad to you at first, try this - I’ve filtered the file to highlight the high frequencies. You can hear the problems most clearly when the vocals start:

Some people describe this effect as “sizzle”, or “swirlies”. It’s not just that I’ve removed all the bass, what I’m pointing out is the unatural bubbling, twinkling “chime-bar” type sound, or as my friend and fellow mastering engineer Nick Watson once called it, the “flocks of tweeting ultrasonic birdies”. It also reminds me of someone crinkling up tin foil !

Once you’ve picked it out, listen the first version again. Doesn’t sound so nice now, does it ? Can you ignore the swirlies, now you know they are there ?

Now download and listen to the original file:

‘Talk About Love - Excerpt’ - 5 MB WAV file

Listen to the clarity, punch, and bite of the WAV, compared to the swirly, soggy mess of an mp3. Which one do you prefer ?

The loss of depth, richness and three-dimensionality is more subtle side-effect, but just as unfortunate. Here’s a snippet of a recording I did for the brilliant Hans Koller, featuring Christine Tobin on vocals:

(This is a much better mp3 encode, with far fewer heinous swirlies. But still…)

Here’s the WAV version:

‘The Great Bear And The Small - Excerpt’ - 11 MB WAV File

Don’t expect the difference here to leap out at you straight away, it’s more a case of feeling it - listen to the swirls of the harp from 30 seconds in, listen to the piano and Christine’s voice - on the wav file, there’s a warmth, and a depth, and a sparkle that in the mp3 has just gone.

Listen to the wav several times over, then switch to the mp3. Do you honestly feel it sounds as good ? The mp3 is OK, but it’s just… meh. I’m not drawn in, my attention wanders, it doesn’t move me.

Something essential has been lost, and you can’t get it back. And once you’ve heard that loss, even cranking the data-rate up doesn’t help. The only solution is a more advanced format, or lossless files.

Try listening to the mp3s in your music collection. Go back and compare them to the CDs you ripped them from.

…Sorry.

My comment: This is what I recognized long time ago. Since the day I started to listen to MP3 files in the 90s, I felt something wrong with them, but couldn't tell what is it. Till now, even there're some foreign producers can't listten to and don't accept the fact that there're differences between WAV and MP3, or 44.1kHz and 96kHz. That's why nowadays there's less and less high sonically quality music, as long as people keep listening to crappy music TV channels, or desktop speakers.

These days, it seems that quantity and pace are more demanded than quality in every aspects of life. People cannot make choice of what they want to listen or watch. The MEDIA industry is doing that for them. Feeding all the garbage day by day surrounding our senses.

Yup, we couldn't change anything, just try to survive and keep our own tastes. Try to keep it high, dudes ;)