What is Apple Digital Master?

Apple Digital Master is a some-what obscure concept. Fundamentally, we know it as the fancy badge on some of the biggest tracks on Apple Music. But, what does it mean? What is an Apple Digital Master?

Read on to find out exactly what an Apple Digital Master is and how it can benefit artists and listeners.

What is an Apple Digital Master?

The simplest expression used by Apple is that an Apple Digital Master (formerly Mastered for iTunes) provides ‘studio-quality’ sound for the listeners of their platform . So how is this done?

Audio File ‘Resolution’

Sound files typically are delivered with a bit-depth of 16-bit and a sampling-rate of 44.1 kHz when uploading to distribution. Usually of course as a lossless file format such as WAV or AIFF. When working professionally many will make use of 24-bit audio which may have a sampling rate of up to 96 kHz or even more. So this means that when encoding music to 16-bit and 44.1 kHz, the music is then no-longer sounding as intended because of a reduction in audio resolution.

An analogy of this process is that film-makers are already filming in 8K or even 12K. Yet in today’s world, we consume content mostly still in regular Full HD (1080p) or up to 4K. So as you can imagine, if you thought 4K looked good, imagine just how good 12K looks! The same principal applies here with audio files.

Data Conversion Processes

Another factor of streamed music is file conversion. Lossless files are quite hefty formats. Using the minimum 16-bit and 44.1 kHz, you are representing sound with a numerical value on the 16-bit scale 44,100 times per second. So this means that for each sample, we need 2 bytes of data, and of course double that if it’s a stereo file. This means that roughly a 4-minute audio file will be around 42 megabytes in data when uncompressed.

The challenge here is that large files take time to load, particularly on lower mobile network speeds. In addition, larger files take up more mobile data which is costly to the consumer. To save on data-warehousing costs, Apple and many other streaming services such as Spotify use lossy compression. This is in addition to subsequent file-formats to store and then deliver their files.

Why Data Conversion is Bad

Data conversion is fantastic for reducing file-sizes to enable streaming services to operate efficiently for example. However when doing so we can encounter clipping, aliasing and various other artefacts such as perceivable quantisation error noise.

As you can imagine, this means that many tracks don’t sound as they would when using the original lossless sound file.

How Apple Digital Master Makes Data Conversion Good

The protocols developed by Apple in their PDF – which can be found here provides some insight. Methods and understandings from this document ensure that the music doesn’t just sound good once mastered, but also after the data-conversion process and on the Apple Music platform. This is done by taking steps at the mastering stage in order to mitigate any possibility for artefacts such as clipping to occur.

So in short, Apple Digital Master is like a piece of guidance or a standard which informs mastering engineers how to do things so that data-converted files can sound as good or at least as close as possible to any lossless counterparts.

What does this mean for listeners?

Not too much, in all honesty. To the average untrained ear a lossy file-format won’t sound much different to a lossless file-format. A little bit like how we don’t really notice too much of a difference between 2K and 4K video resolution. But with that said, to the trained ears, a lossy audio file which follows Apple Digital Master protocols will just not sound quite as bad as a regular lossy audio file.

Apple Digital Masters are submitted at 24-bit and 96 kHz as the minimum requirement. Meaning when future technologies become available for streaming platforms to eventually move over to lossless files, you will already have tracks with the best quality possible.

How can I get an Apple Digital Master?

Although resources are available for you to create your own Apple Digital Master right now and for free. To get ‘the badge’ and to have your track authored as an Apple Digital Master on the Apple Music platform, this must be completed by an authorised mastering house.

If you’d like your own Apple Digital Master, I’m authorised by Apple to provide Apple Digital Masters as an authorised mastering house. Please contact me for more information.