January 2, 2019
What is Apple’s “Mastered for iTunes” format?
Apple has always been on the forefront of increasing the quality of the music in their iTunes catalog. Right now when you download a song, you’ll receive it in the 256kbps AAC format. Yes, it’s a lossless format in which you are losing some data. But it’s very small and it’s hard to prove any audible difference, even in blind tests. Simply put it’s a great format, but it’s only as good as the music you put in there.
The said, Apple started a process or rather a methodology called Mastered for iTunes (MFiT). It is a process that mastering engineers follow in order to submit the “highest quality master” to Apple for sale through iTunes. Mat Leffler-Schulman / Mobtown Studios are certified by Apple and are on the Provider’s List to deliver this service. Only masters from certified mastering facilities can be submitted to Apple or iTunes as MFiT. But it is any better?
Does “Mastered for iTunes” masters sound better than a standard uncompressed 16 or 24-bit master?
Maybe. Of course this is vague, but then again audio can be pretty vague and subjective when everyone hears differently. When you listen to a master that is MFiT approved it means that it originated from the 24-bit master and has no digital clipping. It cant originate from a lower quality 16-bit master. Do those 8-bits really make a difference? Mathematically 24-bit does add more resolution compared to 16-bit but this added resolution doesn’t mean higher quality – which is a very subjective term, it just means it can encode a larger dynamic range, which is theoretically great! So recording at 24-bit isn’t the magic fairy dust that will sprinkle better quality all over your music. You just have the potential for a larger dynamic range in your music. Which means more contrast from the quiet passages to the louder passages and a lower floor noise. Again, this is math. And let’s not confuse this with sampling rate which can theoretically record more audio data than humans can actually hear. Some people say recording at higher sampling rates (like 96kHz and 192kHz) are more true and accurate to the music. But that’s for another day. So simply put the idea is that the more information you have to squeeze in to the lossless format (ie. the 256kbps AAC iTunes file) the better and more true it will sound to the listener.
So this is just the first part of two with making sure you recorded in 24-bits and at least a 44.1kHz sampling rate. The second part is in the actual encoding process of your final masters before you upload to iTunes (or your aggregator like Discmakers or CDBaby). Once you send your masters to iTunes to be encoded if you have overs or clipping your music will be rejected. Digital clipping is a form of waveform distortion. It’s not good. When a signal reaches 0 dBFS on a meter, you’ve run out of headroom and into digital clipping. This is because the recorder has run out of 1s and 0s to accurately convert our signal into digital information. Any extra data is disregarded, which can result in digital clipping–a sine wave hitting its ceiling and becoming a square wave. Whereas analog clipping is more forgiving and pleasant in the way it chops round waveforms into squares, digital clipping precisely lops the head off our delightful sine wave, resulting in harsh distortion which is undesirable to our human ears. We have the tools to make sure there is no clipping in the masters. And we keep average loudness to an acceptable level based on the recommendations.
The specifications we follow are small changes in the industry in the scheme of things. Engineering and mixing practices will most effect the sound of your record. That said, following these best practices and loudness specifications will help keep music from needless peaks and clipping and ugly distortions. Creating masters that aren’t too loud, which in turn will yield records that are more true to the original vision of the artist.
What’s great about MFiT, is it doesn’t cost the musician, mixing engineer, or mastering engineer anything. It’s merely a methodology and workflow to improve the the listening experience.
Is Mat Leffler-Schulman a certified mastering engineer to produce MFiT files?
Yes. I am on Apple’s list of approved MFiT mastering engineers. I follow Apple’s published guidelines, which assures you that your release will be labelled as “Mastered For iTunes” and more importantly, that the resulting AAC compressed files that are sold via iTunes will sound as close as possible to the original 24-bit masters.