AC3 vs AAC vs EAC3 (and DTS): Audio Codecs Compared

Three codecs, two different jobs

These three come up together on TVs, streaming boxes, and video files, but they were built for different purposes. AAC is a general audio codec optimized for efficient stereo (and multichannel) music. AC3 (Dolby Digital) and EAC3 (Dolby Digital Plus, or E-AC-3) are Dolby's surround-sound codecs, designed for cinema, broadcast, and home theater.

AAC vs AC3

For stereo music, AAC is more efficient and generally sounds better at a given bitrate — it's the right tool for songs and podcasts. AC3 exists for surround sound: it packs 5.1 channels into a stream that DVD players, TVs, and AV receivers universally understand. You wouldn't use AC3 for a music library, and you wouldn't use plain stereo AAC for a home-theater surround mix.

AC3 vs EAC3 (E-AC-3)

EAC3 (E-AC-3 / Dolby Digital Plus) is the successor to AC3. It's more efficient — delivering the same or better quality at lower bitrates — and supports more channels (7.1 and up). That efficiency is why streaming services like Netflix and Disney+ use EAC3 for surround audio, where bandwidth matters. AC3 remains common for broadcast TV and physical media because of its enormous installed base of compatible hardware.

E-AC-3 vs AAC: Which Should You Use?

This is the matchup people usually mean when they search "EAC3 vs AAC," and the answer depends on what you're listening on. EAC3 is the better fit for surround sound on a TV, soundbar or AV receiver: it's what streaming services send when your gear supports Dolby Digital Plus, and it's also the format that carries Dolby Atmos on most streaming services. AAC is the better fit for stereo on phones, laptops, earbuds and cars. It plays on practically everything without a Dolby decoder, and at 128 to 256 kbps it sounds excellent for music.

So if you're saving a soundtrack or a TV episode's audio to listen to on headphones, AAC (or MP3) is the practical choice. If you're keeping a movie for a home theater, leave the EAC3 track alone.

Where DTS Fits: DTS vs Dolby Digital

DTS is Dolby's long-running rival. It debuted in cinemas with Jurassic Park in 1993 and shows up on many DVDs and Blu-rays alongside, or instead of, Dolby Digital. According to its specs, the core DTS format runs at 768 kbps or 1.5 Mbps in 5.1, well above AC3's 448 kbps on DVD and 640 kbps maximum. That extra bitrate is why many home theater fans say DTS sounds a little fuller, though at these rates both are hard to tell apart on most systems.

The lossless versions are a different league: DTS-HD Master Audio and Dolby TrueHD are both lossless and mostly found on Blu-ray. Streaming services don't use DTS much. Dolby Digital Plus is the standard there, which is why EAC3 is the surround format you're most likely to run into in a downloaded or recorded video.

So which is "best"?

There's no single winner. It depends on the job:

• Music, phones, general audio: AAC (or Opus at low bitrates).
• Surround sound on DVDs, broadcast, older AV gear: AC3.
• Surround sound on streaming and modern home theater: EAC3.
• Surround on DVD and Blu-ray with a DTS-capable receiver: DTS.

Why Won't My Player Play EAC3 Audio?

A video that plays with no sound, or a "codec not supported" message, usually means the player has no decoder for Dolby's formats. Dolby licenses AC3 and EAC3, and some apps, phones, TVs and PCs don't include the EAC3 decoder. The fixes, from easiest to most involved:

• Use VLC. The free VLC media player lists AC3, E-AC-3 and DTS decoding built in, on Windows, Mac, Linux, Android and iOS.
• Use MPC-HC on Windows. The maintained MPC-HC uses the LAV Filters decoders, which handle Dolby and DTS audio. It's Windows-only.
• Check your media server and TV settings. If you stream through Plex or a similar server, it may need to convert EAC3 on the fly for devices that can't decode it, which is where many "EAC3 not supported" errors come from. On a TV or streaming box, try switching the audio output between passthrough (bitstream) and PCM.
• Convert the audio track. If you only need stereo, converting the EAC3 track to AAC or MP3 makes it play everywhere. See the next section.

How to Convert AC3 or EAC3 to AAC or MP3

Before you convert, know the trade-off: AAC and MP3 files made from a 5.1 track are usually stereo, so the surround channels get mixed down to two. That's fine for headphones, phones and cars, and it's the only way to make the audio play on devices without a Dolby decoder.

• Our free converter (files up to 30MB): upload an .ac3, .eac3, .ec3 or .dts file, or a short MKV or MP4 clip, to the AC3 to MP3 converter, then pick MP3 or AAC. The AAC converter accepts the same files.
• FFmpeg (any size): ffmpeg -i movie.mkv -vn -ac 2 -c:a aac -b:a 256k audio.m4a pulls the audio out of a video, mixes it to stereo and saves AAC.
• XMedia Recode (Windows): a free converter that reads AC3 and MKV and can extract audio to MP3 or M4A in batches.
• HandBrake (Windows, Mac, Linux): the pick when you're re-encoding the whole video. It can convert the audio to AAC or pass AC3, E-AC3 and DTS through unchanged if you want to keep surround.

New to AAC itself? Start with What is AAC?, or see AAC-LC vs HE-AAC for the profiles used in streaming. For how all these formats fit together, read audio formats and codecs explained.

Frequently Asked Questions

Is AAC better than AC3?

For stereo music, yes. AAC is more efficient and sounds better at a given bitrate. AC3 exists for 5.1 surround sound, a job stereo AAC isn't meant for.

What's the difference between AC3 and EAC3?

EAC3 (Dolby Digital Plus) is the newer, more efficient successor to AC3, with support for more channels and lower bitrates. Streaming services favor EAC3; broadcast and DVDs still use AC3.

Is EAC3 better than AAC?

For surround sound on a TV or home theater, yes: EAC3 is built for 5.1 and 7.1 and carries Dolby Atmos on most streaming services. For stereo music on phones and headphones, AAC is the better choice because it's efficient and plays everywhere.

Which has the best surround sound?

For modern streaming, EAC3. For universal hardware compatibility, AC3. On disc, DTS runs at higher bitrates than AC3, and the lossless DTS-HD Master Audio and Dolby TrueHD formats beat all of them.

Why is there no sound when I play a video with EAC3 audio?

The player doesn't have a decoder for Dolby Digital Plus. Try VLC or, on Windows, MPC-HC, both of which decode EAC3. You can also convert the audio track to AAC or MP3 so any device can play it.

Does converting AC3 or EAC3 keep surround sound?

Usually not. AAC and MP3 conversions for phones and headphones are mixed down to stereo. To keep 5.1, leave the original track as it is or pass it through unchanged with a tool like HandBrake.

Can I convert AC3 or EAC3 to AAC?

Yes. Upload the file to our free AC3 to MP3 converter and choose AAC or MP3; files up to 30MB work, and surround is mixed down to stereo. For longer files, FFmpeg, XMedia Recode or HandBrake will do it.

Sources

• Wikipedia: Dolby Digital (AC-3)
• Wikipedia: Dolby Digital Plus (E-AC-3)
• Wikipedia: DTS
• VideoLAN: VLC features and supported formats
• MPC-HC (clsid2) on GitHub
• XMedia Recode
• HandBrake Documentation: Audio codecs