Auro 3D Audio Surround Sound Format Basics

Get fully immersed in sound with Auro 3D Audio

Auro 3D Audio Logo and Speaker Setup

 Auro Technologies | Marantz

Between Dolby and DTS, there is an abundance of surround sound formats you can take advantage of in most home theater setups. However, there is an alternative to consider that provides an immersive surround sound experience available on only select home theater receivers and AV preamp/processors, and that's Auro 3D Audio.

Auro 3D Audio Engine
Auro Technologies

What Is Auro 3D Audio?

What We Like
  • Backward compatible with 5.1 and 7.1 channel audio.

  • Accommodates 10.1, 11.1, and even 13.1 channel configurations.

  • DTS:X can be mapped to an Auro 3D Audio speaker setup.

  • Upmixer can adapt 2, 5.1, or 7.1 channel audio to Auro 3D Audio speaker layout.

What We Don't Like
  • Requires a lot of speakers for fully immersive sound.

  • Auro 3D Audio and Dolby Atmos speaker mapping not compatible.

  • Not a lot of available content in comparison with Dolby and DTS formats.

  • Expensive to implement.

Auro 3D Audio is a consumer version of the Barco Auro 11.1 channel surround sound playback system used in some cinemas. If you haven't experienced Barco Audio 11.1, check out a list of cinemas and films that you may be able to view.

In the home theater space, Auro 3D Audio is a competitor to the Dolby Atmos and DTS:X immersive surround sound formats but has its own characteristics.

The goal of Auro 3D Audio for home theater is to provide an immersive surround sound experience (similar to Dolby Atmos and DTS:X) by encasing the listening environment in a "bubble." However, unlike Dolby Atmos and DTS:X, Auro 3D audio is channel-based, rather than object-based. In other words, during the mixing process, sounds are assigned to specific channels (thus the requirement for more speakers), instead of a specific point in space.

With Auro 3D Audio, sounds are assigned to specific channels instead of a specific point in space.

Another difference between Auro 3D and Dolby Atmos/DTS:X is how the encoded signal is transferred from a source device to an AV preamp/processor or home theater receiver. Dolby Atmos and DTS:X use a codec that is embedded within a specific bitstream format, whereas the codec for the Auro 3D Audio can be embedded within a standard uncompressed 5.1 channel PCM soundtrack that can be placed on a Blu-ray Disc or Ultra HD Blu-ray Disc.

This means that Auro 3D Audio is backward compatible—if your AV preamp processor or home theater receiver is not Auro 3D-enabled, you still have access to a standard 5.1 or 7.1 channel uncompressed audio signal.

Since the Auro 3D Audio codec algorithms can be embedded in a 5.1 channel PCM soundtrack, most, if not all Blu-ray Disc players can pass this information from a Blu-ray Disc to an AV Preamp/Processor or home theater receiver that provides Auro 3D Audio decoding. However, to access Auro 3D Audio soundtracks that may be included on an Ultra HD format Blu-ray Disc, you need an Ultra HD Blu-ray Disc player.

Auro 3D Audio Speaker Layout Options

For listening, Auro 3D Audio starts with a traditional 5.1 channel speaker layer and subwoofer. Surrounding the listening room (above the listening position) is another set of front and surround speakers (that means a two-layer speaker layout). More specifically, the layout looks like this:

Auro 3D Audio Speaker Diagrams
Auro Technologies
  • Level 1: 5.1 channels—front left, center, front right, left surround, right surround, and subwoofer.
  • Level 2: Height Layer—front left, front right, left surround, right surround. This results in a 9.1 channel speaker setup.
  • Level 3 (Optional): Top Layer—If you go for the full 10.1 channel option, then you would add one ceiling mounted speaker that is placed directly above the listening position. This is referred to as the VOG (Voice of God) channel.

Although the 9.1 and 10.1 channel options provide a more than suitable Auro 3D listening experience, if you have an AV preamp/processor/amplifier combination or home theater receiver that is properly equipped, Auro 3D can also accommodate 11.1 and 13.1 channel configurations.

In these configurations, a center channel speaker can be added to the height layer of a 10.1 channel setup, resulting in a total of 11.1 channels. To extend this further, if you start with a 7.1 channel setup on Level 1, then the result is a total setup of 13.1 channels.

What Auro 3D Audio Sounds Like

At this point, you are probably thinking, "That's a lot of speakers!" That is definitely true, and for the vast majority of consumers, that is a turn-off. However, the proof is in the listening.

Auro 3D Audio Sound Layer Diagram
Auro Technologies

When listening to Auro 3D Audio, what is distinctive is that although Dolby Atmos and DTS:X provide a similar immersive surround effect with movies, Auro 3D Audio is most impressive with music.

When the height layer is activated, the sound not only goes vertical but also becomes wider in the physical gap between the front and rear speakers. This means that there is no need to have an additional set of wide speakers to get a wide-open surround sound experience.

  • Movies: Auro 3D Audio provides a very realistic sonic environment where the sound is both immersive and directional; dialog is anchored well, effects sounds have the desired dramatic impact, and background (transient) sounds are detailed and brought out but also balanced in the right degree against the main sound elements.
  • Music: The results are definitely impressive when compared to standard 2-channel audio reproduction. As a listener, you are placed in the room acoustics where the recording was made (such as a club, auditorium, church, or arena). In addition, the balance between vocals and instruments is accurate. Of course, a lot depends on how the recordings were mixed, but if done well, the results are impressive. Even if you are a die-hard 2-channel stereo fan, and have a chance to check out a musical performance in Auro 3D Audio, definitely sit and take a serious listen.

Despite delivering an excellent sound experience, the main problem with Auro 3D Audio is that it requires a lot more speakers to achieve the immersive height effect. This is unlike DTS:X, which can work with a standard 5.1 or 7.1 setup, or Dolby Atmos which can work with a standard 5.1 channel speaker setup, with the addition of two vertically firing or ceiling mounted speakers.

The speaker layout requirements for Auro 3D Audio and Dolby Atmos are different, and not normally compatible. Auro 3D's multiple speaker layers and single ceiling speaker differ from Dolby Atmos, which requires one horizontal speaker level, and two or four ceiling or vertically firing speakers for height sounds.

Auro 3D cannot naturally map to a Dolby Atmos speaker configuration, and Dolby Atmos cannot naturally map to an Auro 3D audio configuration. However, Marantz and Denon solve this problem by providing a "unified" speaker setup configuration. Using the "unified" configuration, when confronted by an Auro 3D audio setup by mapping the Dolby Atmos height signals to left and right front speakers in an Auro 3D audio height layer.

On the other hand, DTS:X, which is speaker layout agnostic, can map to an entire Auro 3D audio speaker setup.

Auro 3D Audio Content

In order to get the full benefit of Auro 3D Audio, you need movie or music content that is properly encoded. This includes select movies on Blu-ray or Ultra HD Blu-ray Discs, as well as select audio-only content on Pure Audio Blu-ray Discs.

Auro 3D Audio Content Examples

In addition, as part of the implementation of this format, Auro Technologies provides an additional upmixer (referred to as Auro-Matic) that can take advantage of the Auro 3D Audio Speaker layout for non-Auro 3D Audio encoded content.

Auro-Matic expands the surround sound experience of traditional 2/5.1/7.1 channel content, as well as bringing out sonic detail and opening up mono (yes, I said mono) source material, without exaggerating the intent of the original recording.

Auro 3D Audio for Headphones

Auro 3D Audio Head Diagram
Auro Technologies

In addition to the home theater version of Auro 3D Audio, there is a headphone version.

The Auro 3D headphone experience works with any set of Binaural (stereo) headphones. This makes Auro 3D Audio very practical for use both in home theater receivers and AV processors with headphone outputs, as well as mobile devices, such as smartphones and tablets.

How to Get Auro 3D Audio for Your Home Theater

Denon AVR-X4400H 9.2 Channel Home Theater Receiver

Auro 3D may be included or added via a firmware update in a compatible AV processor or home theater receiver. However, devices that require a firmware update to add Auro 3D Audio may have an associated fee (typically $199).

Brands that offer Auro 3D Audio for select AV processors or home theater receivers include: