DTS (Digital Theater Systems) is a standard home theater audio format developed in 1993 to compete with Dolby Digital. If used in your home theater system, it provides surround sound for 5.1, 6.1, and 7.1 setups. Compared to Dolby Digital, DTS uses higher bitrate, thereby offering superior sound quality.
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M4A is a filename extension for AAC container format and is developed by Apple Inc. M4A music is bought on the iTunes Store and does not come with DRM protection. In terms of quality, M4A is better than MP3 because it is lossless but still compressed. This means that it occupies less storage space and doesn’t lose quality over time.
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