Los Angeles — Audyssey Laboratories expects June shipments of the first A/V receivers equipped with its Dynamic Surround Expansion (DSX) post-processing technology, which adds front-height speakers and a pair of image-widening left-right speakers to traditional 5.1-speaker setups.
DSX is the latest post-processing technology introduced to boost the realism of surround-sound playback. At International CES in January Dolby and DTSunveiled separate post-processing matrix-decoding technologies that derive height information from two-, 5.1- and 7.1-channel soundtracks for playback through two front-height speakers in a multispeaker surround system. DTS’s technology adds two optional horizontal-plane surround channels to create a soundfield with up to 11.1 channels.
Audyssey, which licenses room-correction and other post-processing technologies, adds a second pair of horizontal-plane front speakers to expand the width of the front soundstage and, optionally, a pair of front-height channels to deepen the soundstage.
“DSX provides the necessary acoustical and perceptual cues for a more realistic reproduction of surround content,” CTO Chris Kyriakakis said. DSX augments 5.1 systems “with the correct direction, time of arrival and frequency response characteristics to achieve a seamless and expanded soundstage,” the company added.
DSX also processes the surround signal in the time and frequency domain to enhance the envelopment of two to four surround speakers in a home theater system and “improve the blend between the front and surround channels for a seamless and immersive soundstage,” the company added. Consumers with existing 7.1 systems can adapt their system to DSX by moving the back surround speakers to the wide locations.
Nonetheless, DSX doesn’t require more than two surround speakers because “experiments have shown that human localization is better in front than to the sides or behind,” the company said. “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,” Audyssey continued. “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. “