Definitions for "Dolby Prologic"
Keywords:  prologic, mono, decode, analogue, vhs
An active analogue surround sound system that is the standard on VHS tape and most current television broadcasts. A Dolby Prologic decoder takes in two-channel, Dolby Surround-encoded audio and converts it into left, right, center, and surround channels.
True 'Cinema Style' surround sound from 5 speakers (2 x front, 2 x rear, 1 centre).
This is the English and pan-European name for Dolby Surround, an analogue format for surround sound where there is no digital connection necessary, just normal stereo (phono) outputs/inputs. The amplifier on the receiving end must be capable of Dolby Pro Logic decoding. The main difference between this and Dolby Digital is that the rear speakers are in mono (both output exactly the same) and there is no dedicated subwoofer channel. Of surround sound televisions actually sold the majority are of Pro-Logic standard though most offer little hope of upgrade ability.