Since the rumors of Apple’s interest in high resolution audio downloads
first surfaced in late 2011, a growing number of people have become interested in the topic.
Apple very quietly bypassed the music industry record labels' participation in any such high-resolution download project by launching its Mastered for iTunes
A number of tech-enthusiast websites
did notice the launch of the initiative however and shortly thereafter started to report on this potentially huge music development.
In response, members of the music recording industry have begun to look at Mastered for iTunes to see if it holds any true potential to solve the problem of low-resolution files overshadowing better quality products. Bobby Owsinski
, a L.A.-based recording engineer recently outlined the professional music community factions that pit those who believe a separate master file must be used for iTunes versus those who feel the status quo is just fine.
Owsinski also outlines Apple’s mastering guideline recommendations that include:
- Always use the highest resolution file available (24-bit/96kHz, if it’s available)
- Apple recommends to mastering engineers not to compress a track. Owsinski says there’s a feature called Sound Check in iTunes that lets users hear all of their music files at the same level. He says a highly compressed track will actually sound less impactful because of the Sound Check technology.
- Moving beyond some of the technical aspects of mastering he adds that compressing is becoming less relevant because file storage is becoming less of an issue for consumers. This is why he theorizes that Apple is pushing its AAC Plus lossless high-resolution format (The existence of AAC Plus Lossless could not be verified).
The British mastering engineer Ian Shepherd goes deeper in his analysis of Mastered for iTunes
by using a music engineering tool called a null test. Shepherd explains this procedure as a method of reversing the phase of a song’s waveform so that after a song’s waveforms and volumes are matched in software a mixing engineer can play them back to see if the song’s out of phase waveform cancels or nulls out the normal version of the song. In his comparison Shepherd lines up a Red Hot Chili Peppers song that was downloaded in the Mastered for iTunes format with a CD version of the same song and an AAC-encoded version of the song.
After his comparison of the three digital music files, Shepherd says there was a sonic difference between the Mastered for iTunes waveform and the CD waveform. Whereas he says comparing the CD waveform and AAC-encoded files revealed far fewer sonic differences, adding that this proves to him Apple’s Mastered for iTunes isn’t 'closer to the CD' than a standard AAC file from Apple's iTunes store, as engineers involved in the releases have claimed.
“What is not true is to say is that this [Mastered for iTunes] sounds closer to the [CD version] than this [AAC file],” he states. “It makes perfect sense that software engineers spend a lot of time making AAC, MP3 encoders; whatever encoders you choose sound as close as possible to the original CD. How could a mastering engineer using his ears be able to [do] a better job than that [AAC or MP3 encoder]?”
If all this wasn't confusing enough Shepherd points out another area for potential confusion is the fact that two different things are being labelled as "Mastered for iTunes." One is the specific "Mastered for iTunes" releases like the Red Hot Chili Peppers album Shepherd uses as an example. "This is what I'm emphasizing in the video, and where I believe the real slight-of-hand is being pulled," he explains. '"Optimizing' for lossy codecs shouldn't be necessary, and my test shows that [in the case of Red Hot Chili Peppers at least] it isn't necessary. But the other thing is the set of guidelines and tools that Apple have put on their 'Mastered for iTunes' page. These [guidelines] I think are absolutely fine, and actually quite valuable for making people aware of mastering issues like the loudness war. Personally I think the benefits of a 24/96 source after being reduced to a 16/44 AAC file will be trivial, but the prospect of higher quality releases in future is appealing, and there's nothing wrong with having high-quality sample-rate conversion and encoding tools readily available."
Based on this early feedback from the pro audio industry, Apple and the music industry will be better served to find some type of tiered pricing policy that offers consumers a choice of download formats that actually live up to the claim of “CD quality” or "high-resolution audio.” If these parties can’t reach a legitimate compromise, the people who really know this business will expose these claims for what they really are: marketing hype.