Auro 3D Audio Surround Sound Format Basics

Between Dolby and DTS, there are many 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.

What Is Auro 3D Audio?

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.

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

Auro 3D Audio in a home theater provides 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. During the mixing process, sounds are assigned to specific channels (thus the requirement for more speakers) 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 embed a codec within a specific bitstream format. The Auro 3D Audio codec can be embedded in a standard uncompressed 5.1 channel PCM soundtrack and 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. 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:

• 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, place one ceiling-mounted speaker directly above the listening position. This is referred to as the VOG (Voice of God) channel.

The 9.1 and 10.1 channel options provide a more than suitable Auro 3D listening experience. Still, if you have an AV preamp/processor/amplifier combination or home theater receiver that is properly equipped, Auro 3D can 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, 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 many consumers, that is a turn-off. However, the proof is in the listening.

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 goes vertical and becomes wider in the physical gap between the front and rear speakers. This means that you don't need an additional set of wide speakers to get a wide-open surround sound experience.

• Movies: Auro 3D Audio provides a realistic sonic environment where the sound is immersive and directional. The dialog is anchored well, effects sounds have the desired dramatic impact, and background (transient) sounds are detailed, brought out, and balanced in the right degree against the main sound elements.
• Music: The results are impressive when compared to standard two-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). The balance between vocals and instruments is accurate. However, the sound depends on how the recordings were mixed. If done well, the results are impressive. Even if you are a two-channel stereo fan, take a serious listen if you have a chance to check out a musical performance in Auro 3D Audio.

Despite delivering an excellent sound experience, the main problem with Auro 3D Audio is that it requires more speakers to achieve the immersive height effect. This is unlike DTS:X, which works with a standard 5.1 or 7.1 setup, or Dolby Atmos, which works 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. Marantz and Denon solve this by providing a unified speaker setup configuration. When confronted by an Auro 3D Audio setup, use the unified configuration to map the Dolby Atmos height signals to the 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

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 Disc, as well as select audio-only content on Pure Audio Blu-ray Disc.

In addition, as part of the implementation of this format, Auro Technologies provides an additional upmixer (referred to as Auro-Matic) that takes 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. It brings out sonic detail and opens up mono source material without exaggerating the intent of the original recording.

Auro 3D Audio for Headphones

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

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

How to Get Auro 3D Audio for Your Home Theater

Auro 3D may be included or added with 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 and home theater receivers include Denon, Marantz, Storm Audio, and DataSat.