Height-Enhanced Surround Hits the Street

March 12, 2009 — Onkyo’s TX-SR607 surround receiver ($599) is the first from any manufacturer to include Dolby Pro Logic IIz, the new height-enhanced surround mode from Dolby Laboratories.

Link: http://hometheatermag.com/news/031209height/


Yamaha has been doing this in their AVRs for several years, calling it “presence speakers”.

But when it come to 6.1 and 7.1 soundtracks the rear surround channels and front presence surround share the same internal amplifiers. This means that the rear surrounds and the front presence channels are mutually exclusive and they cannot play simultaneously. The receiver decides which pair to enable and which pair to disable based on the source material. For 5.1 and fewer channel sources, the front presence channels are enabled and the rear surrounds are disabled. For 6.1 and 7.1 channel sources, the front channels are disabled and the rear surrounds are enabled. This means that for 6.1 and 7.1 soundtracks, the front ambiance gets mixed in with the main speakers and the results can sound muddy. You also lose the dialog lift effect.


DD PLIIz doesn’t change that. A 7-ch amp is still a 7-ch amp. It’s just the same thing with a different name. A new decoder doesn’t magically add 2 more channels to your amp.

Yamaha’s Cinema DSP approach was to create a presence channel from DSP which added room ambiance. It was about the creating a listening environment. Dolby is creating new audio channels from existing information in the soundtrack. Dolby’s Pro Logic IIz uses different technology, though the end result may be similar. Many game developers are already adopting Dolby’s new Pro Logic IIz encoders but this is yet to be seen from the movie studios.

Only time will tell. :slight_smile:


DSP by any other name is still DSP. :wink: