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Dolby Pro Logic IIx Launched

Indianapolis — Dolby plans a CEDIA Expo unveiling of its new Pro Logic IIx technology, described as the industry’s first licensed technology to upconvert two-channel audio, matrixed Dolby Surround, and 5.1-channel audio into 6.1- and 7.1-channel surround.

Dolby Pro Logic II, in contrast, processes stereo and matrixed Dolby Surround into a 5.1-channel experience. It appears in home and car audio products, including the Volvo XC90’s OEM sound system.

The launch is “in response to manufacturers wanting a Dolby-branded 7.1 solution,” said consumer marketing director Craig Eggers.

During the Expo, two to three manufacturers will demonstrate working IIx products in their booths, and Dolby’s booth will include a live demo plus static displays of IIx products.

Eggers expects multiple suppliers to roll out IIx-equipped preamp/processors and step-up receivers in the fourth quarter. The suppliers will include, but aren’t limited to, Arcam, Yamaha, Marantz, Meridian, Tag McLaren, Pioneer, and Fosgate Audionics. Onkyo, Integra and Meridian will offer the technology as a flash-memory upgrade to select products already available.

Those new models could include $600-$900 HTiBs available as early as May, depending on manufacturing cycles, Eggers said. A handful of HTiBs equipped with 6.1-channel Dolby Digital EX is already available at those price points, he noted.

“We’re late to the table with it,” Eggers said of IIx, but the wait will make IIx the “first technology to offer the choice of processing traditional stereo [and Dolby Surround] music and movie content into a 6.1- or 7.1-channel listening experience,” the company said. The technology, therefore, is “easily applicable to any surround system configuration,” the company added.

In contrast, THX Surround EX processes 5.1-channel Dolby Digital and Dolby Digital EX discs into 7.1, and Harman’s Logic 7 converts stereo, matrixed surround and Dolby Digital 5.1 to 7.1. In addition, DTS’s Neo:6 upconverts stereo and matrixed surround to 5.1 and 6.1. SRS’s Circle Surround II upconverts to 5.1 and 6.1, but unlike the other technologies, it upconverts from sources down to mono. Proprietary Bose technology upconverts to 5.1, but not to 6.1, from sources down to mono.

When IIx processes stereo and Dolby Surround sources, Eggers explained, it “applies logic decoding to the left and right surrounds, not to create four discrete [surround] channels but to create four full-bandwidth stereo-like channels.” The channels deliver a “seamless experience” as sound pans from one side-surround speaker through the back surrounds to the other side-surround speaker. Each surround-speaker signal is unique but not discrete, he said.

When Pro Logic IIx processes a 5.1-channel source, it operates as an expanded Dolby EX decoder, steering the two surround channels to four separate outputs with high separation, Eggers said.

Besides upconverting movie soundtracks, a Pro Logic IIx receiver or preamp/processor will also upconvert DVD-Audio and SACD music into 7.1 output under two circumstances: The receiver or preamp processor accesses the audio signals in digital form via a 1394 digital interface or a proprietary digital interface. Alternatively, the content may be transported via five analog cables, but the receiver or processor must be able to apply DSP to the analog inputs.

To Pro Logic II’s movie and music modes, IIx adds a game mode, Eggers added. “More than 30 percent of all gamers are connected to a 5.1 home theater system,” he said. Dolby Pro Logic IIx ensures that bass effects panned only to the surrounds are fully reproduced in satellite/subwoofer systems.

In the movie and music modes of Pro Logic II and IIx, in contrast, the bass from the surround channels is normally not summed with front-channel bass when creating a subwoofer feed. That’s to avoid unwanted phase effects and level modulations when two-channel material is upconverted, Eggers said. Gamers, he said, “need all the menacing cues they can get when an enemy comes up from behind.”

Upconversion to 7.1 has advantages over 6.1 upconversion, some suppliers said. Systems with a single back-channel speaker fall prey to combing effects that reinforce certain frequencies, and it can be hard to distinguish if the sound is coming from the front-center or rear-center channel, they noted. For that reason, some receivers with EX 6.1-channel decoders feature seven full-range amplifier channels to support two back-surround speakers, each delivering the same mono signal.