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I hate mp3, and you’ll be told why this post.

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 Ogg Vorbis, FLAC or AAC – stop reading now !

Here again? Good.

First, I need to make this clear – I don’t have anything against loss audio or data compression in itself – I use 128kbps AAC files to do most of my casual listening on an iPod – they sound fine. Obviously not as good as the original CDs, 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. None of them have killed music in the long run, nor will mp3, or loss compression in general. So, why is this 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 methods of encoding and sound better to varying degrees, but only FAILs for mp3.

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

Listen to yourself

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

      3TalkAboutLoveAmLow

(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. When the vocals begin, you can hear the problems most clearly:

      swirlies

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 reminds me of somebody crinkling tin foil as well!

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

Listen now to the original file:

      3TalkAboutLove

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

The loss of depth, wealth, and 3D 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:

      GreatBearTheSmall

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

Here’s the WAV version:

      GreatBearTheSmall

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.

Several times listen to the wav, then switch to the mp3. Do you feel it sounds like good honestly? 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. A more advanced format or lossless files are the only solution.

Try to listen to your music collection’s mp3s. Compare them to the CDs from which you ripped them.

…Sorry.

I’ve had lots of interest in this post, and lots of discussion, especially on link-sharing sites. There are a few common answers I would like to respond to here.

Nobody uses mp3s of 128 kbps

Wrong. If you’ve made this comment, you probably already know about LAME and the all other flavours of mp3 codec, and you probably do choose to use higher bit-rates, but you’re in the minority. Most “regular listeners” go for the default settings – and even in iTunes this is only 160 kbps.

It sounds good at 192/320 kbps

Sometimes. This depends so heavily on the material, the encoder and the codec – you simply can’t make blanket assumptions. Ironically one of the factors making mp3 so popular – the fact that there are so many encoders and players, some of which are free – also makes it much more difficult to get a decent encode. By contrast, the Apple grip has at least consistently high encoding standards over the AAC format.

You’re just an Apple fanboy

No. Well alright, yes – I am a big fan of Apple’s products, but there are plenty of other alternatives to mp3 – OGG Vorbis, FLAC etc. The only reason I mention AAC a lot is it’s a format I have deep experience of, and always sounded good (but not perfect !) to me.

And something else.

To everyone who keeps saying “just use 320 kbps”, I say – why ?!? mp3 simply has inherent limitations compared to other formats. The whole point of lossy audio is to save space. That saving is 90% at 128 kbps – well worth it. At 320 kbps though, that saving is only 60% and it still doesn’t sound great – I’d far rather go with FLAC or Apple lossless, which can often achieve an almost equivalent 50% saving in space, and have something that sounds identical to the source.

Actualization #2 (2014):

Five years later, and we still have the mp3 (and overall loss data compression).

AAC sounds even better since Apple’s Mastered for iTunes initiative, and even offers tantalising glimpses of a lossless future. Meanwhile Neil Young has his heart in the right place with his Pono initiative – but I have some concerns. And Harman seem to regard the whole thing as nothing more than a marketing opportunity.

Try this test for another chance to hear the 128 kbps mp3 problem for yourself:

It’s only 128 kbps versus 320 kbps unfortunately, but it’s an interesting exercise all the same.

Here’s how I did:

Let’s just go lossless and be done with it !