Definition: Dolby Prologic IIz processing is an enhancement that extends surround sound vertically. Dolby Prologic IIz offers the option of adding two more front speakers that are placed above the left and right main speakers. This feature adds a "vertical" or overhead component to the surround sound field (great for rain, helicopter, plane flyover effects). Dolby Prologic IIz can be added to either a 5.1 channel or 7.1 channel setup.
For more details, check out the official Dolby Prologic IIz page.
Yamaha offers a similar technology on some of its home theater receivers called Presence.
Pronunciation: Dolby Pro Logic Two Zee
Also Known As: Dolby Pro Logic IIz
Alternate Spellings: Dolby Pro Logic IIz
