Sunday, November 8, 2009

To Dolby IIz Or Not To Dolby IIz, The New Question.

To Dolby IIz or not to Dolby IIz, that is the new question. There is a new surround sound contender, but let’s first discuss the history of Dolby surround sound. We did not used to have all the surround sound speakers that we have today. More is always better (supposedly) and that has been the route taken with surround sound. It is the route still taken today, with the desire for bigger and better.

It all started with mono. Just a single speaker or signal was all we used to hear. For ages that was all we had in sound reproduction. Then in the 50’s we got an upgrade to two speakers in the form of stereo. Stereo was all the craze back then. For decades that was the best we had.

Then in the 70’s came movies like Star Wars and Close Encounters of the Third Kind, and with it came the introduction of surround sound. This was thanks to the company we know and would all become familiar with- Dolby. Dolby Surround had emerged. Elevating the number of speakers to three it was the first innovation since stereo, and the first true surround sound format. The speakers were front left, front right, a phantom center channel created from the front left and right speakers (but not a discrete channel), and a single rear speaker for surround. For many years everyone was happy.

Next in the 80’s came Dolby Pro Logic. What it added was an additional speaker. We now had an actual speaker for the center channel. In the 90’s Dolby up’s the anti with Dolby AC-3 or more commonly known as Dolby Digital. Now we had the traditional 5.1 channels that we are all familiar with: Front left, front right, center, rear right, rear left, and subwoofer. Not only did we now have 5.1 channels, but they were also discrete. That meant that if a helicopter in a movie flew over from the front left to the rear right, you would hear it go from the front left to over you to the rear left. All 5 channels are also full range, so you could use large tower speakers for all channels if you wanted to. DTS also entered the arena as an alternative surround sound format.

Still not satisfied with the number of speakers, in 1999 Dolby Digital EX was introduced. This added an additional channel to the rear that was matrixed from the rear left and right speaker for a total of 6.1 or 7.1 speakers including the subwoofer. In 2000 Dolby went a step further and introduced Dolby Pro Logic II. Now, Dolby was able to matrix 5.1 from a stereo source. Next in line for Dolby came Pro Logic IIx which matrixed 6.1 or 7.1 from a stereo source. Dolby just kept adding extra speakers to the rear. We went from one to two, to now four rear channel speakers, with no change to the front soundstage. Now we have Dolby Pro Logic IIz, where Dolby has introduced two additional front speakers, as height speakers, matrixed from the soundtrack.