iPhone ringtone format explained. m4r, m4a. AAC vs MP3
iPhone ringtones – audio files with .m4r extension (AAC codec)
iPhone, along with all iOS devices, uses AAC (Advanced Audio Coding) as the default codec for audio files. Other consumer electronics manufacturers also use the codec as a default, such as Sony for its Playstation 3, while many others support the format. Although audio ‘quality’ is largely subjective it is accepted that the AAC codec provides better quality than MP3 at comparable bit rates (according to pioneering German audio engineer, Karlheinz Brandenburg’s paper ‘MP3 and AAC Explained’). AAC is popular with smartphone manufacturers, supported by Android, Nokia and Blackberry amongst others.
Back to the iPhone, the file extension for such audio files is .m4a. So when you are listening to a track purchased from iTunes, or ripped from CD using iTunes default settings, you are listening to an .m4a. Ringtones simply use the AAC codec but with a different file extension – .m4r. It is most likely that Apple specified .m4r as opposed to .m4a for ringtones in order to exert some control over the use of such audio files.
How to convert .m4a to .m4r for use as ringtones
Any .m4a audio file can be quickly ‘converted’ to the correct format for use as a ringtone on the iPhone. The process is not really a conversion at all, rather a simple change to the file extension. All you need to do is change file extension manually.
- Get your .m4a file ready.
- Right click on the file name to select the file name text.
- Change the ‘a’ to an ‘r’ by simply typing over it.
- Hit enter.
- OSX will ask if you wan to keep the new file extension, confirm this. (It’s a similar process on Windows.)
You now have an audio file that can be synced to your iPhone and used as a ringtone!
What is the maximum length of an iPhone ringtone?
There is one trick to look out for, iPhone ringtones have a maximum length of around 40 seconds. The maximum length is often incorrectly noted as 30 seconds.
If you are inclined to read technical documents, you can read more about the AAC audio codec and how it stacks up against the MP3 here in the above mentioned article MP3 and AAC Explained by Brandenburg.