If you’ve ever looked through the audio settings on your TV, soundbar or streaming device, you may have seen options for Dolby Digital and Dolby Digital Plus.

The names make Dolby Digital Plus sound like a straightforward upgrade — but what actually changes, and will you hear a difference?

The short answer is that Dolby Digital Plus is a newer and more capable surround-sound format. It supports higher bitrates, up to 7.1 channels and can be used to deliver Dolby Atmos. Dolby Digital is an older format that supports up to 5.1 channels and remains widely used, particularly with older home-theatre equipment.

For most modern TVs, streaming devices and sound systems, Dolby Digital Plus is generally the better choice.

Here’s how the two formats compare.

What is Dolby Digital?

Dolby Digital is a digital surround-sound format developed by Dolby Laboratories.

You may also see it referred to as AC-3.

It became particularly popular with DVDs, digital television, cinemas and home-theatre systems, helping bring 5.1-channel surround sound into millions of homes.

A typical 5.1 setup contains:

• Front left speaker
• Centre speaker
• Front right speaker
• Rear or surround left speaker
• Rear or surround right speaker
• One low-frequency effects channel for the subwoofer

The “5” therefore represents the five main audio channels, while the “.1” refers to the dedicated bass channel.

Dolby Digital can carry anything from mono audio through to 5.1-channel surround sound.

Like Dolby Digital Plus, it is a lossy format. This means some audio information is removed during compression to significantly reduce the amount of data required.

Dolby lists Dolby Digital as supporting data rates of up to 640 kbps.

What is Dolby Digital Plus?

Dolby Digital Plus, also known as E-AC-3 or Enhanced AC-3, is a more advanced version of Dolby Digital.

It was developed to deliver better audio capabilities while using bandwidth efficiently — something that has made it particularly useful for streaming services and digital media.

Dolby Digital Plus supports up to 7.1 discrete channels compared with the 5.1-channel maximum of standard Dolby Digital.

A 7.1 system typically adds two additional surround channels, allowing sound to be positioned more accurately around the listener.

However, Dolby Digital Plus does not always mean 7.1 audio.

A movie or TV show encoded using Dolby Digital Plus could still contain a 5.1 soundtrack. The format simply gives content providers the option of delivering more channels when required.

Dolby Digital vs Dolby Digital Plus: Key differences

The biggest differences come down to channel support, compression efficiency, bitrate and support for newer audio technologies.

Feature	Dolby Digital	Dolby Digital Plus
Codec name	AC-3	E-AC-3
Maximum surround channels	5.1	7.1
Compression	Lossy	Lossy
Maximum listed bitrate	640 kbps	Up to 6 Mbps
Designed for streaming	Limited compared with DD+	Yes
Can deliver Dolby Atmos	Generally no	Yes
Older device compatibility	Excellent	Depends on equipment

Dolby Digital Plus can operate from 32 kbps up to 6 Mbps and was designed to scale across different devices and bandwidth conditions.

That makes it particularly useful when streaming high-quality multichannel audio over the internet.

Does Dolby Digital Plus sound better?

Potentially, yes.

Dolby Digital Plus uses more advanced compression technology and supports higher data rates than Dolby Digital.

This means it can preserve more audio information while still keeping file sizes manageable.

Dolby itself describes Digital Plus as providing additional channels, higher potential data rates and more efficient coding than the original Dolby Digital system.

However, seeing “Dolby Digital Plus” on your television doesn’t automatically guarantee that something will sound dramatically better.

Audio quality also depends on factors such as:

• How the original soundtrack was mixed
• The bitrate used by the streaming service
• Your speakers or soundbar
• Your room
• Your TV or streaming device
• Whether the content actually uses additional channels

A high-quality Dolby Digital 5.1 mix could therefore sound better than a poorly encoded Dolby Digital Plus soundtrack.

Does Dolby Digital Plus support Dolby Atmos?

Yes.

This is one of the most important differences for modern streaming.

Dolby Digital Plus can be used as a delivery format for Dolby Atmos.

Atmos adds object-based audio information that allows compatible sound systems to position sounds more dynamically around the listener rather than relying entirely on fixed speaker channels.

This is particularly useful for effects such as helicopters flying overhead, rain falling around you or objects moving across a room.

Streaming services frequently use Dolby Digital Plus to deliver compressed Dolby Atmos soundtracks.

This is different from Dolby TrueHD, which is a lossless audio format that can also carry Dolby Atmos and is commonly associated with formats such as Blu-ray.

So you may encounter:

Dolby Digital Plus + Dolby Atmos

or

Dolby TrueHD + Dolby Atmos

Both can provide Atmos, but the underlying audio format is different.

Is Dolby Digital Plus lossless?

No.

Both Dolby Digital and Dolby Digital Plus use lossy compression.

This means some audio information is discarded to reduce the size of the audio stream.

Dolby TrueHD, by comparison, is a lossless format.

For streaming, however, file size and bandwidth matter considerably.

Dolby Digital Plus provides a useful compromise between audio quality, surround-sound capability and the amount of data required to deliver it.

That is one reason it has become well suited to internet streaming.

Why do streaming services use Dolby Digital Plus?

Streaming companies need to deliver high-quality audio to millions of different devices while keeping bandwidth requirements under control.

Dolby Digital Plus was designed with these types of applications in mind.

Its advantages include:

• Efficient audio compression
• Support for 5.1 and 7.1 surround sound
• Support for Dolby Atmos delivery
• Scalable bitrates
• Support across TVs, computers, smartphones and streaming hardware

Dolby specifically describes Digital Plus as being designed for streaming, on-demand and downloaded content.

Instead of needing the considerably higher bandwidth associated with lossless audio, streaming providers can offer immersive surround sound while keeping data usage relatively low.

Can a 5.1 system use Dolby Digital Plus?

Yes.

You don’t need a 7.1 speaker system just because your device is playing Dolby Digital Plus.

Dolby Digital Plus supports both 5.1 and 7.1 configurations.

If you have a compatible 5.1 sound system, a Dolby Digital Plus soundtrack can still be played through your existing speaker arrangement.

You aren’t missing two speakers simply because the Dolby Digital Plus logo appears on your TV.

Is Dolby Digital Plus backwards compatible?

There is an important distinction here.

Dolby says Dolby Digital Plus content can be converted to a traditional Dolby Digital signal for equipment that only supports Dolby Digital.

That conversion usually needs to happen through a compatible TV, Blu-ray player, streaming box or AV device.

A very old receiver that only understands Dolby Digital cannot necessarily decode a raw Dolby Digital Plus stream itself.

This is one reason you may sometimes need to change your TV’s digital audio output settings when connecting older audio equipment.

Should I choose Dolby Digital or Dolby Digital Plus?

If all of your equipment supports Dolby Digital Plus, choose Dolby Digital Plus.

It provides greater flexibility and supports modern features such as 7.1-channel audio and Dolby Atmos while still being capable of carrying ordinary 5.1 sound.

Dolby Digital may still be preferable if you are using older equipment that doesn’t properly support Dolby Digital Plus.

A simple rule is:

Modern TV + modern soundbar or AV receiver = Dolby Digital Plus

Older AV receiver or compatibility problems = Dolby Digital

If Dolby Digital Plus works correctly with your setup, there is generally little reason to deliberately switch back to standard Dolby Digital.

Is Dolby Digital Plus the same as Dolby Atmos?

No.

This is a common source of confusion.

Dolby Digital Plus is an audio codec.

Dolby Atmos is an immersive audio technology.

Dolby Digital Plus can be used to transport Dolby Atmos information, but the two names don’t describe the same thing.

Think of Dolby Digital Plus as the delivery method and Dolby Atmos as the audio experience being carried within it.

Is Dolby Digital Plus better than Dolby Digital 5.1?

Overall, Dolby Digital Plus is the more capable technology.

It can support more channels, higher bitrates, more efficient compression and technologies including Dolby Atmos.

But that doesn’t mean every Dolby Digital Plus soundtrack will automatically sound better than every Dolby Digital soundtrack.

If you’re choosing between the two settings on a modern television, streaming device or sound system, Dolby Digital Plus is usually the one to select.

For older home-theatre equipment, standard Dolby Digital remains an extremely useful format thanks to its widespread compatibility.

Dolby Digital vs Dolby Digital Plus: The verdict

Dolby Digital helped make 5.1 surround sound mainstream and remains widely supported today.

Dolby Digital Plus builds on that foundation.

It supports up to 7.1 channels, much higher potential bitrates, more efficient delivery and the ability to carry Dolby Atmos, making it particularly well suited to today’s streaming world.

For most people using modern entertainment equipment, Dolby Digital Plus is the better option.

But don’t worry if your system only supports Dolby Digital.

A good 5.1 Dolby Digital soundtrack can still deliver an excellent home-cinema experience.