iTunes improvement???

Apple has just announced a new section of iTunes, this section will carry music which has been specially encoded to improve the perceived reproduction. I say 'perceived' because in fact it does nothing for the actual reproduction of the original instruments!!

This simply continues the fallacy that since the human ear can only hear 20-20kHz that is all we need to play music. Which is nonsense, to hear the music you need to reproduce the sound of the original instruments, and these produce frequencies much above 20kHz which give them their individual timbre. So any music system needs to be able to manage very low frequencies (organs go down to 16Hz) and very high frequencies (trumpets produce harmonics above 50kHz), a reasonable system should manage 5Hz-50kHz, not the usually quoted 20-20kHz.

Let's see what it is all about

Sound in studios is recorded digitally with 24bit words and at 96kHz. This is the original sound heard by the sound engineer. according to his settings this original can have some clipping on load peaks and some compressed dynamic range as he adjusts the volume. Possible dynamic range or 24bit/96kHz digital recording is 126dB, with a bandwidth of 48kHz.

Apple is now asking the studios to submit to them this 24/96 media. They will then convert it to the CD standard of16bit/44kHz using an Apple CAF 32 bit file intermediary, this will avoid certain distortions introduced in the down-sampling process. A sharp cut off filter will be used at 20kHz, dynamic range will be limited to the CD's 84dB, and only 15% of original data will remain!

Think that a full orchestra has a dynamic range of over 130dB, the CD is a pretty bad medium to carry realistic audio dynamics.

Next Apple will check for clipping, that is where the signal goes upto or over the maximum that the digital representation can handle, known as 0dBS. Beyond that their is no bigger digital number to represent the signal peak and it is chopped off. Any clipping is reported back to the engineers and they can re-master the tracks.

Next Apple will convert the file to AAC 256kbps, eliminating frequencies and harmonics supposedly not perceived by human ears. Cutting data down to 1/5th of the CD size, or just 3% of original.

Thus you get your song on iTunes. But is it any better?

No, it's clever but dumb.

The music industry has resisted higher quality distribution directly to, again, prevent "piracy". They clapped DRM on the 24/96 standard DVD-A or SACD disks and on Blu-ray, which effectively killed their market, but they don't care.

Now I believe Apple is trying slowly to drag the recording industry into the modern digital age. First step, get them to give Apple 24/96 masters. Second step define the best way to get this sound squeezed into 256kbps AAC compressed format, losing as little as possible of the original dynamics (good move but impossible outcome).

Next? If I was asked about the future, then what I would like to see is a two tier music distribution, first getting rid of the oddity, the CD 16/44.1, format and moving this to 16/48 with AAC compression - a standard that existing iPods could play - and a full blown 24/96 format with non-lossy compression.

So iTunes launches 16/48 lossy AAC and true 24/96 distribution in a non-lossy compressed format such as ALAC or FLAC. iPods can handle the 16/48, Macs can today easily handle the 24/96.

That's the goal we are all waiting for.

And next, for Apple to be the first company to produce an "iPod+" capable of storing and processing 24/96 audio files, both on the digital side (requires 32bit processing) and on the storage side (requires x10 increase in memory) and on the analog to digital conversion side (to ensure the device can output up to 48kHz frequencies). All this is technically possible. But it may take a while to update or load your music, even over fast WiFi... at 1GB per album...

There is just one other small copyright problem, that is the studios use of "windowing" to only allow release of tracks in certain countries at certain times, for example today many 24/96 tracks are only available in the USA. This is a misuse of copyright problem that has to be solved by arm twisting or legal changes.