Dolby has added a new format. It's called Pro Logic IIz, and it adds two height channels to an existing surround setup. Special processing adds a convincing illusion of height to the front channels.

The height channels are used in front; Dolby research has shown that there is greater benefit to adding height to the front than to the rear. The first product to add Pro Logic IIz is new Onkyo AV Receiver; more about that when we get to visit the Onkyo booth. Pri Logic IIz, despite the name, may be used with all Dolby discrete surround formats. its compatibility with DTS, however, is still an open question.