Dolby Pro Logic / Pro Logic II


Dolby Labs introduced Pro Logic surround in 1987. Pro Logic improved on the original Dolby Surround format by adding a matrix center channel. This made Dolby Pro Logic a four-channel surround matrix created from just two discreet (stereo) channels. The rear channel still had bandwidth limitations so only certain sounds were diverted to those speakers.

Pro Logic remains alive and well today as a method of decoding two-channel material. Even with the most advanced multi-channel home theater system today, Pro Logic is still there to enhance our two channel sources. Most of what we watch on TV is presented in two channels, as are music CDs.
Dolby Pro Logic at a glance: