Audyssey DSX Highlights
- More enveloping surround sound. 7.1, 9.1 and 11.1 surround sound produces amazingly detailed and immersive experiences. The Height and Wide channels make movies sound three-dimensional. With Audyssey DSX, explosions, storms and battle scenes come to life.
- Scalable setup. DSX-enabled AVRs can deliver content to 7, 9 or 11 speakers, allowing you to build a surround sound system with the appropriate number of speakers for your space and budget.
- A key component in your AVR. Audyssey DSX comes standard on many premium home theater receivers – be sure yours has it.
Audyssey’s Surround Sound Solution
Today, movies are mixed with five discreet channels and nearly every home and movie theater in the world uses the 5.1 standard: five speakers and one subwoofer (read blog). But after years of research, Audyssey scientists discovered that by adding more channels in the right places surround sound could be even better. Audyssey DSX not only creates new Wide and Height channels, but also provides Surround Envelopment Processing to enhance Front and Back channels. This technology processes the standard surround signals in the time and frequency domains to improve the perceived sense of envelopment and blending with the other speakers in the surround system.
By expanding 5.1 sound, Audyssey DSX technology delivers true 7.1, 9.1 and 11.1 surround sound. The result isn’t just the most immersive, realistic home theater sound on the market, but a new standard in surround sound.
Technical Details
Why use more speakers?
Research in human hearing shows that we can hear many more directions than what current systems provide. We use the direct sound to localize the direction of sources and the reflected sound to perceive the size of the soundstage.
Experiments have shown that human localization is better in front than to the sides or behind. This means that for front-weighted content such as movies and most music, good engineering dictates that we employ more channels in the front hemisphere than the back. Imaging is also better horizontally than vertically and so good engineering also dictates that channels must first be added in the same plane as our ears before going to higher elevations.
Perception is not the only factor. The physics of room acoustics for music have been well studied, and their correlation with subjective impression increasingly understood over the last 30 years. This research has shown that we have strong built-in preferences for the direction, frequency response, and time of arrival of reflected sound. Additional channels and surround sound processing are needed to properly render these components.
Wides Before Heights
One key finding from the research is that first side wall reflections play a great role in determining subjective impression. The most important direction of reflected sound was found to be ±60° relative to the front. Audyssey DSX provides a pair of Wide channels (LW and RW) at ±60° with appropriate frequency response and perceptual processing to match these requirements of human hearing. These Wide channels are much more critical in the presentation of a realistic soundstage than the Back Surround channels found in traditional 7.1 systems. Adding surround channels behind the listener has a very small impact compared to the increase in envelopment and soundstage width that the Wide channels provide.
The next most important acoustical and perceptual cues come from reflections above the front stage. Audyssey DSX provides a pair of Height channels (LH and RH) that should be ideally positioned at a 45° elevation angle.