What is the difference between .m4r and .ac3?
- Extension
 - .m4r
 - .ac3
 
- Format
 - Binary
 - Binary
 
- Category
 - Audio
 - Audio
 
- Developer
 - Apple Inc.
 - Dolby Laboratories
 
- Description
 - M4R is an iTunes ringtone file that stores mono channel audio. They are identical to the M4A format files only that they are correctly used for ringtones.
 - Audio file saved in the AC-3 (Dolby Digital) audio format; can include up to six channels of audio (DD 5.1 surround sound with subwoofer output); uses lossy compression and often used as the format for DVDs, cinema theaters, and game consoles.
 
- MIME Type
 - audio/x-m4r
 - audio/ac3
 
- Sample
 - sample.ac3
 
- Wikipedia
 - .m4r on Wikipedia
 - .ac3 on Wikipedia