Thursday, August 27, 2009

Dolby Pro Logic II - Being Surrounded

Dolby Pro Logic II is the ancestor of the original Dolby Pro Logic technology. The main idea behind Pro Logic was to expand any stereo sound source into 4 channels (front left, right, center, and one surround behind the listener). This quickly developed into Pro Logic II, which splits the stereo source into 5 channels, more common in homes today, with two surround channels.

Dolby has also introduced additional iterations of its PLII technology known as Pro Logic IIx and Pro Logic IIz. PLIIx splits the stereo sound into 7 channels to be listened to with a 7.1 system, and PLIIz adds two height channels to PLIIx (one above the front left and right channels).

The great thing about PLII is the ability to enjoy a much more expansive surround experience in a home theater with only stereo source audio. iPods and other MP3 players are popular due to their portability, but the sound must be compressed into a smaller stereo format. PLII expands this audio into a more realistic surround experience, which can be especially enjoyable when viewing movies that are encoded in stereo. Dolby even has a solution for when the listener is using headphones rather than a home theater system. Dolby Headphone can be used with any set of headphones to sound more like surround sound. Combined with PLII, Dolby Headphone .

Learn more here.