What is “Mastered for iTunes”?
Mastered for iTunes is a mastering process and distribution format. It allows mixing and mastering by engineers to publish music in higher accuracy (with minimal distortion and noise). The process ensures that artists will benefit most from this format.
Master VS Premaster
Like any other digital music distribution channel, iTunes really does not want mastering: they want a premaster. The so-called “mastering” process is actually two interconnected, but functionally discrete processes:
- Premastering, which covers all the aesthetic solutions associated with the preparation of mixes. He answers any questions related to how it will sound.
- Mastering, which is the ultimate means of delivering music to an audience. In the case of iTunes, this includes encoding the Apple AAC file and adding the appropriate metadata.
It does not matter if you are a label directly linked to iTunes or a standalone composer using an aggregator; the company wants to receive specific preliminary digital audio so that they can do encoding (i.e. mastering) within the company.
The main premise for Mastered for iTunes was that AAC is not a CD-DA, so unique solutions are required to achieve the best results. This was true (and accepted) for vinyl, cassette, broadcasting, etc. The technology required for listening to streaming music certainly requires a similar (if not more complex) consideration.
IF YOU A MUSIC CONSUMER
“Mastered for iTunes” – means the material is intended for sale on iTunes. When the store first appeared, the accepted practice was to use the same wizard as for CDs, but many engineers who process music from 2000 to 2010 began to over-compress the audio files (set a high gain). It has been proven that with this maximization, there are many problems and losses (especially in mp3 format).
Apple decided to create several methods that encourage the use of more conservative mastering levels. Then they created a new process designed to receive high-resolution master tracks for publication on iTunes.
By purchasing the release of “Mastered for iTunes”, you buy a product that has been mixed and mastered for publication on this particular resource. If you could compare a regular CD master and an MFiT release while listening to a high-quality full-range sound system, you would notice improved transient clarity and music dynamics. The purpose of MFiT is that if you had access to a 24-bit uncompressed wave file and compared it with the version for aityuns, then they would sound almost identical to most listeners.
The Mastered for iTunes initiative is like a technical improvement and a change in the practice of mixing and mastering by engineers, as it helps to distract from super-loud tracks. Anyone who listens at a high quality level, in an environment that allows them to hear all the details of the music, will potentially be rewarded with a wider dynamic range. In this case, the premaster is more profitable, since when playing in the company’s player, the levels of all compositions are equal to one value. You can trace how a pinched track becomes quieter (but its artifacts remain audible), and a track whose values do not reach the required levels is compressed without loss.
Please note that the Apple format is still considered “compressed” because it is converted for a small file size and convenient download via the Internet. If you are an audiophile who regularly listens to music on high-quality acoustics, then the “Mastered for iTunes” format is the best choice with a 24-bit extension.
IF YOU ARE A MUSIC MANUFACTURER OR PUBLISHER
If you create and submit songs for publication on iTunes, then “Mastered for iTunes” is an important step forward for online music. This is true for Apple Music.
As you know, a very large part of the music available in the store is in AAC (Advanced Audio Coding) format in 128 kbps, as this was the format that Apple started working with in 2003. The company later switched to plus, introducing a variable bit rate (VBR) of 256 kbps. At double data transfer speed, files, songs sound much better than the original format.
Today, mastering engineers create mixes with high data rates and sampling rates, such as 24-bit 96 kHz. In response to this, Apple released a two-stage encoding process. The first step involves high-level sampling rate conversion (SRC), which reduces the master to a standard sampling frequency of 44.1 kHz, but outputs it with a 32-bit floating point. This is important because peaks often fall below 0dBFS when downgraded, which causes distortion. Using a 32-bit floating file, Apple prevents this.
The second stage is encoding a 32-bit file in Apple AAC format without any additional smoothing. This means that the compressed version of AAC, which gets into the iTunes library, will contain all the dynamics that existed in your original 24-bit file, without adding noise. Of course, the levels of a 24-bit file are extremely low, but it is always better to prevent the addition of noise at any stage of production.
In the end, this means that music consumers will be able to purchase songs that are as close as possible to the original uncompressed wav file.
Would a Mastered for iTunes wizard be better than a standard uncompressed 16 or 24-bit wizard?
Since “better” is a subjective term, it will therefore be correct to state that this version will sound “different” than the original uncompressed master. The conversion uses compression in AAC, and it is technically inferior to an uncompressed audio file. On the other hand, the AAC format is designed to appear transparent and musical to human ears. Although some listeners will hear small differences when making parallel comparisons, these “technical differences” are relatively insignificant in nature.
Thanks to utilities like roundtrip, the mastering engineer can see the results of AAC encoding live and optimize the sound of the MFiT wizard for the Mastered for iTunes format. Optimization can mean many different things. For some engineers, the solution is to lower the peak volume, while for others, a deeper change and refinement is required. The goal is to match the AAC version with the original 24-bit master file as closely as possible.
In our opinion, converting for sale to iTunes does not guarantee a better sounding product than an uncompressed file. Yes, it is much better than standard mp3, but everything is also far from wave and flac.
How to publish and sell your music in the iTunes store
A relatively limited number of approved iTunes aggregators can send songs that meet the requirements of Mastered for iTunes. Here you can view a complete list of Apple Approved Content Aggregators as well as iTunes Approved (MFiT)
Establishing a relationship with one of the representatives, they explained that some aggregators independently prepare materials for release in the store. You pay to send your album twice, as two separate releases:
- “normal” release for all online stores except iTunes using a standard 16-bit file
- iTunes release using a 24-bit MFiT specification file. The releases are completely separate – they will even have their own separate barcodes for tracking sales.
How to find out who is a certified MFiT provider?
Mastering engineers advertise MFiT as part of their services. Apple maintains a centralized list of approved master craftsmen (by the way, it has not been updated for a long time, maybe this check has lost its meaning), but sources say that they apply only to labels. Taking this into account, we recommend looking for an engineer who promotes and supports this type of mastering.
File Format Requirements for Mastering
To meet the technical requirements of Mastered for iTunes, you need to send your track in uncompressed wav 24-bit (for example, 24bit, 96kHz). Part of the Apple manual is to limit or completely prevent peaks between samples. Please note that if your track is created in the 16-bit 44.1 kHz format, then there is no difference and the benefit of converting to a higher extension. Music that was actually recorded and mixed in high expansion will have even greater effect. The goal is to preserve the original extension.
Whether you are going to graduate from it or not, we recommend the following practices at the stages of recording, mixing and mastering:
- record 24-bit music from 44.1 kHz or higher using conservative levels (an RMS level of -24dBFS is ideal, peaks should be no higher than -6dBFS)
- execute (or order information from us) with a sampling frequency of 24 bits 96 kHz, using a mixing platform that allows you to configure the project to a 32 or 64-bit floating point frequency
- with a frequency of 96 kHz or higher, keeping the levels throughout the chain conservative level (RMS level -24dBFS is also ideal)
- focus on tonality, drama and expression when mixing (create an impressive picture that will appeal to the listener).
- export the track by properly preparing it according to the requirements of the host studio.
Apple also provides all the necessary information about MFIT on its Mastered for iTunes website, as well as some handy tools completely free (Mac only). They are designed to help you avoid common problems such as clipping / clipping.
Here is the list available today:
- Master for iTunes Droplet is a drag and drop utility that allows you to quickly encode tracks to the Apple iTunes Plus format to hear how they sound.
- afconvert is an alternative command line based tool.
- afclip – use this file to check the cropping of peak points.
- AURoundTripAAC Audio Unit is a comparison tool that allows you to check for problems after converting files.
- Audio to WAVE Droplet – automatically creates a * .WAV (Waveform Audio File) file from any other audio file, such as * .mp3.
It’s important to note that tools and processes are equally necessary, even if you don’t plan to publish your music on iTunes. We hope that these tools will also help music producers better understand how they can produce music with higher sound quality just by following the general recommended practices.
Why does it require a cutoff of peak points?
Sound compression is never good. It not only reduces the extension (clarity) of the sound, but also creates problems for translation / conversion to mp3 and AAC. Such problems occur at several stages of processing, even when converting the sampling rate or converting the format to a lossy format.
Apple claim that they do not reject entries if they have random peak values. But they should be avoided at all costs at all stages of production – recording, mixing and mastering.
“MASTERED FOR ITUNES” HELPS DISTINCT!
The technical improvements that were introduced with Mastered for iTunes are relatively small compared to changes in the mixing and mastering practices of engineers. This should not minimize the advantage of using a 24-bit master over a 16-bit one, but, in our opinion, the biggest advantage is that Apple helps engineers and labels use the recommended methods of mastering music, avoiding the appearance of tracks that are too loud. They even offer some recommendations for maintaining the dynamics of music in their MFiT documentation. Even if the differences are not so obvious to the masses who listen to music on headphones, those with better quality playback systems will certainly appreciate the benefits of this new format for years to come.