Apple’s new “Mastered for iTunes” has been causing quite a buzz recently – and causing lots of confusion.
I’m going to try and explain it all as clearly as I can.
[Update edit: I started out sceptical, but after new clues have been discovered about Apple's plans for "Mastered for iTunes", I'm actually very excited by the opportunity it presents - check out the "Stop Press" update at the end of this post.]
There are four five ways that the term “Mastered for iTunes” can be interpreted.
1. Mastered for iTunes is a set of utilities and guidelines
The easiest to understand and least controversial definition of “Mastered for iTunes” is described on this page on Apple’s site, here:
Basically it’s a set of guidelines for people to follow, to ensure you get the best quality versions of you music files available in the iTunes Music Store. Apple also include free utilities that allow you to preview how your files will sound once they’re encoded.
The guidelines are great – they encourage you to submit the highest quality files, and suggest how avoid falling into common traps that affect the quality – for example avoiding clipping and not over-cooking the music’s level because of the so-called “Loudness Wars“.
At the moment, the final files are still 44.1 KHz, 256 Kbps AAC files – so, they’re perceptually encoded files, using lossy compression – basically like high-class mp3s.
Whether you’ll hear a real difference from submitting a 24/96 version of your music is debatable – my quick tests suggest the answer is “not much” – but Apple also hint that in future they will use the high-quality masters to offer better downloadable versions in future, which can only be a good thing.
[Edit: Some people are getting confused about exactly what "Mastered with iTunes" means, and what it is - for all the details, click here.]
So, the “Mastered for iTunes” concept has been getting a lot of press in the last couple of days, and there’s a claim that’s being made that bugs me.
Specifically, it’s being said that the “Mastered for iTunes” versions ‘sound closer to the CD’.
Not true.
Test-ably not true.
Don’t believe me ? Watch the video. It proves this claim is untrue, by using a technique know as ‘null testing’ to highlight the sonic differences.
As I say in the video, people may well prefer the “Mastered for iTunes” versions, and there’s absolutely no reason not to make a specific master for a particular release format – but to say that it sounds ‘closer to the CD’ is just wrong.
Let me know what you think in the comments !
Update
Just to be clear, it’s the specific mastering processing that’s supposed to be “optimised for mastering” that I’m calling out here – the sonic choices made by the mastering engineer.
Apple have release an excellent set of guidelines on Mastering for iTunes, and I’m delighted to see a clear discussion of issues like the loudness wars, sample rate conversion, dither and clipping.
BUT the fact that the new Apple encoders can correctly handle high sample rates, and should make a better job on the conversion, STILL doesn’t mean that the files will sound ‘closer to CD’.
In fact, since at the end of the day we’re still getting a lossy encode, it’s my opinion that the advantages of higher bit-depths and sample rates will be completely outweighed by the AAC encoding.
If Apple really care about giving us high-quality audio, they should offer lossless formats… but that’s a whole other blog post !
Update 2
A few people have asked me where the claim that “Mastered for iTunes” masters sound “closer to the CD” comes from.
To be clear, this isn’t something that Apple themselves have said, to my knowledge.
The phrase originally came from Scott Hull’s comment on the first post I wrote about Mastering for iTunes, discussing the RHCP release:
“The goal of the unique AAC master of the Chili Peppers album was to make it sound as close to the CD as possible. The ears involved in the process felt it was a success. Pick up the CD and compare to the AAC file with your ears. It’s really damn close. Keep in mind, I’m not addressing whether or not you like the sound of the CD. It was RR’s goal to make the Itunes file as true to the sound of the CD as possible despite the data reduction. A lot of time, effort and careful listening went into this project. This was not just media hype.”
And, here’s Rick Rubin saying that AAC encoding needs to be compensated for:
“The problem? The AAC compression algorithm is “quite quirky.” Without compressing a song, and carefully listening to it, then comparing to the uncompressed master, there’s no way to predict how the sound will change. Vlado Meller, another engineer at Masterdisk, described mastering for iTunes “like polishing your Bentley in total darkness, then turning on the lights to see where you missed.”
“There are no accurate real-time tools to help you hear what the algorithm will do,” VanDette said. “It was not uncommon to revise tracks three, four, even five times until I got something that compared well with the CD.”
Slightly different words, but the same spin. And still not true.
There are two kinds of audio compression, and they’re not the same. But people get them confused all the time, and it’s driving me nuts.
Today, it was Bob Stanley from St Etienne, being interviewed on Radio 4′s PM programme. The discussion was prompted by Neil Young‘s recent claims that the sound of music today makes him angry. You can hear PM’s discussion of this issue here, about 41 minutes in.
During this discussion though, they managed to completely mangle the distinctions between the two kinds of compression, and the whole ‘analogue versus digital’ debate, too.
They’re not alone though, it happens all the time.
So in an attempt to clear the water, I’m going to explain the difference, using sponges.
I don’t go out and see live shows nearly as often as I should, in fact. [Note to self !]
And I really love hearing acoustic music live. I love enjoy loud, distorted guitars as much as the next man, but there’s something magical about hearing music in it’s simplest, most honest form.
The superb video above captures that, beautifully – and also explains in only a few minutes how the internet opens up a whole new world of possibilities for independent musicians to tour, build their audience and see the world, if they have the desire, determination and drive.
Well, it’s true – there doesn’t seem to be much point in denying it any more – after all, Radiohead are one of the biggest bands in the world, and they’re prog, right ?
So while it may not be exactly hip, I don’t think that enjoying progressive rock can be considered quite the crime against music that it once was.
And, being me, one thing I’ve always enjoyed about “progressive” music is that it almost always sounds superb.
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