E-AC-3 (Dolby Digital Plus)
E-AC-3, also called Dolby Digital Plus, is an audio codec that delivers surround sound at lower bitrates than the original AC-3 (Dolby Digital). It supports more channels than AC-3, and streaming services commonly use it for 5.1 and 7.1 audio. It is also the most common way to carry Dolby Atmos in streaming. Most modern smart TVs, streaming sticks and soundbars support it.
Why it matters
E-AC-3 gives viewers surround sound and Dolby Atmos at bitrates that work over the internet. For premium services, that sound is part of what subscribers pay for. Offering it alongside AAC stereo keeps every device covered.
How it works
- The audio mix, such as 5.1, 7.1 or an Atmos mix, is fed to the encoder.
- The encoder removes sounds listeners are unlikely to notice and packs the rest efficiently.
- The E-AC-3 track is delivered as an extra audio rendition alongside AAC.
- Compatible TVs and soundbars decode it; other devices play the AAC track.
What is the difference between Dolby Digital and Dolby Digital Plus?
Dolby Digital Plus (E-AC-3) is the more efficient successor to Dolby Digital (AC-3). It delivers similar or better surround sound at lower bitrates, supports more channels and can carry Dolby Atmos. Most E-AC-3 decoders can also handle AC-3, so it suits streaming to modern TVs.
Does Dolby Digital Plus support Atmos?
Yes, Dolby Digital Plus can carry Dolby Atmos, and it is the most common way Atmos reaches streaming viewers. The Atmos information rides along in a way that older Dolby Digital Plus decoders can still play as regular surround sound.
Where it's used
Streaming services for films and series, along with premium video platforms, use E-AC-3 to deliver surround sound and Dolby Atmos to living room devices, with AAC as fallback.
By the numbers
- E-AC-3 supports up to 15 full-bandwidth audio channels at a maximum bitrate of 6.144 Mbit/s. (Wikipedia: Dolby Digital Plus)
