The Audyssey DSX Surround Sound Format

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

Audyssey, the maker of several automatic speaker setup and room correction systems, followed up with its own system. Audyssey DSX, which stands for Dynamic Surround Expansion, also enhances the surround sound experience.

Dynamic Surround Expansion Basics

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

Wide channel speakers are meant to be placed 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 present in 5.1 or 7.1 channel soundtracks and directs them to the front height or wide channels, enabling an enveloping 3D 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. Still, you must choose between using front height or wide speakers.

In a 9.1 channel DSX setup, the speaker arrangement is 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.

If limited to a 7.1 channel setup, you can eliminate either the front height or wide speakers. Should you have to choose, Audyssey recommends adding wide speakers over 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 certain sounds coming from overhead.
• If you opt for the wide option within 7.1 channels, the speaker setup would consist of front left, front center, front right, left and right wide, surround left and right, and subwoofer. The wide speaker setup option fills the gaps between the surround and front speakers and adds a larger front soundstage.

Audyssey DSX and DSX 2

Home theater receivers that are equipped with Audyssey DSX can up-mix 5.1 or 7.1 channel content. DSX 2 adds the ability to up-mix 2.0, 5.1, or 7.1 channel content into the expanded surround sound environment.

The Bottom Line

Some home theater receivers are equipped with the Audyssey DSX or DSX2 surround sound formats. With the introduction of Dolby Atmos, DTS:X, and Auro3D Audio, 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.