The Audyssey DSX Surround Sound Format

Adding width and height to surround sound

Yamaha Presence and Dolby's ProLogic IIz were the first audio processing formats to introduce the concept of adding front height channels into a surround sound setup, and DTS briefly provided a similar option with its DTS Neo:X surround sound processing. The goal of these formats is to provide a more immersive surround sound experience.

Audyssey, developers of several automatic speaker setup and room correction systems incorporated into many home theater receivers, followed with its own twist designed to enhance the surround sound experience, Audyssey DSX (which stands for Dynamic Surround Expansion).

Audyssey DSX Speaker Placement Example
Audyssey

Dynamic Surround Expansion Basics

Audyssey DSX adds the option on select home theater receivers for adding front height and/or wide channel speakers.

Wide channel speakers are intended to be placed in between the left and right surround speakers and the left and right front speakers. This option eliminates sound dips that can occur between the front and surround speakers, especially in a larger room.

Similar to Yamaha Presence and Dolby ProLogic IIz, DSX doesn't require studios to mix soundtracks specifically for the expanded sound field. The DSX processor looks for cues already present in 5.1 or 7.1 channel soundtracks and directs them to added front height and/or wide channels, enabling a more enveloping "3D" sound listening environment.

Channel and Speaker Configurations

To fully experience Audyssey DSX, you need a 9.1 or 11.1 channel home theater receiver that is Audyssey DSX-enabled. However, DSX is adaptable for use in 7.1 channel configurations but you have to choose between using front height or wide speakers.

In a 9.1 channel DSX setup, the speakers are arranged as follows:

  • Front Left
  • Front Left Height
  • Front Center
  • Front Right
  • Front Right Height
  • Wide Left
  • Wide Right
  • Surround Left
  • Surround Right.

The Wide Left and Wide Right speakers are placed on the sides between the front and surround speakers. The .1 channel is reserved for the Subwoofer(s).

For 11.1 channel setups, you would add Surround Back Left and Surround Back Right speakers.

If limited to a 7.1 channel setup, you can eliminate either the front height or wide speakers. Audyssey recommends if you have to choose, adding wide speakers should be a higher priority over adding the front height speakers.

  • For a 7.1 channel setup, if you opt for height, the speaker layout would be Front Left, Front Height, Front Center, Front Right, Front Height, Surround Left and Right, and Subwoofer. The sounds from the height speakers project toward the listening position, giving the sensation of selected sounds coming from overhead.
  • If you opt for the wide option within 7.1 channels, your speaker setup would consist of Front Left, Front Center, Front Right, Left and Right Wide, and Surround Left and Right and Subwoofer. The wide speaker setup option fills in the gaps between the surround and front speakers, as well as adding a larger front soundstage.

Audyssey DSX and DSX 2

Home Theater receivers that are equipped with Audyssey DSX have the ability to upmix 5.1 or 7.1 channel content, while DSX 2 adds the ability to upmix 2.0, 5.1, or 7.1 channel content into the intended expanded surround sound environment.

The Bottom Line

Although there are some home theater receivers equipped with the Audyssey DSX or DSX2 surround sound processing formats, with the introduction of the Dolby Atmos, DTS:X, and Auro3D Audio immersive surround sound formats in 2015/16, home theater receiver makers have moved away from the Dolby ProLogic IIz and Audyssey DSX/DSX2 options. However, Yamaha still includes its Presence surround sound processing option on some of its home theater receivers.

If you have a home theater receiver or happen to buy one (most likely used) that has either DSX or DSX2, it can still be used to expand your surround sound listening experience over standard 5.1 or 7.1 as it doesn't require specific encoding on the source end.