DolbyÆ Surround Pro Logic II Ushers In The Next Generation Of Matrix Surround Sound

By Perry Sun, Widescreen Review

21-Jun-00

In the age of discrete 5.1-channel DolbyÆ Digital and DTSÆ Digital Surroundô, one would tend to believe that the days of Dolby Surround and matrix multi-channel audio are numbered. If this is your point of view, you'd better reconsider. Dolby Laboratories has just introduced the next wave of matrix decoding, and it's bigger and better than ever.Known as Dolby Surround Pro Logic II, this isn't merely an improvement in steering logic over its predecessor. This new scheme can do what Pro LogicÆ was able to do, and much more. It is a 6:2:6 matrix encode-decode system, meaning that up to six channels (front left-center-right and surround left-center-right) can be combined into two and subsequently processed to recover the original six channels. It's a grand, timely update to the well-established matrix surround domain that will bridge the gap between discrete and matrix multi-channel audio.This new technology was designed by Jim Fosgate, President of Fosgate Laboratories, known as the bona fide legend of surround sound processing. Regarding Dolby Surround Pro Logic II, Fosgate remarked that ""This is a result of almost 25 years of my work in this field."" He continued, ""I had a fantasy in my mind of what I wanted this to sound like, and I believe I have met it. I believe that I have come up with the final answer to this technology. I truly believe that this is a breakthrough!"" (See Jim Fosgate's analog prototype circuit board for Pro Logic II, pictured.)Fosgate emphasized that the essential aspect of this new surround sound system was the incorporation of feedback to improve the accuracy and performance with separating channels upon decoding. The result is an unprecedented improvement in stability and imaging, as well as the capability to accommodate six channels. Additionally, Fosgate has said that Dolby Surround Pro Logic II is designed to work not only with encoded material, but also to create a convincing surround soundfield with conventional two-channel stereo sources.Dolby Laboratories will be licensing this new technology exclusively, both as analog and digital implementations, and it is anticipated that surround sound receivers and various consumer components unveiled early next year will feature Dolby Surround Pro Logic II. New licensees are expected to be announced later this year. Rockford Fosgate's RFQ5000 is the first licensed Dolby Pro Logic II unit, and is targeted for the auto environment. The vast catalog of Dolby Surround software on videotape, DVD and television broadcasts will be fully compatible with the new decoding via a separate four-channel mode offering improved performance over Pro Logic.Look forward to Widescreen Review's firsthand impressions of Dolby Surround Pro Logic II, and an in-depth conversation with Jim Fosgate in a future issue.