Originally Posted by archiguy
That brings up another tech question for the class.
Can anyone tell me what the difference is between plain ol' Dolby Digital, which I get on all my cable/satellite feeds, and DD+ which I get on many BD's and most of the streaming services? Is it just "better" DD for some reason? Is it a whole separate audio track or CODEC? Is it two more channels, i.e. 7.1 instead of 5.1?
What's the deal with DD+ anyway?
It is a better DD, or more accurately, DD extended (not the DD-E, but DD+). Quoting from an old Home Theater Forum post
"Dolby Digital Plus" is Extended AC-3 (E-AC3). It incorporates improved coding models which preserve more audio information when used at low bitrates (such as 192 kbps). Additionally, it allows for additional data from channel arrangements beyond 5.1. Specifically, in the case of 7.1 audio, it supplies the 4 rear channels as a separate packet : there is a 5.1 core, and then an extension which replaces the 2 rear channels of 5.1 with 4 new rear channels.
So DD+ is DD expanded with extensions (still has the core DD) to make things like 7.1 possible as well as other improvements in performance, etc.
The connection to the apps available for streaming is that most (if not all) apps have moved from DD to DD+. I noticed this when all of my used apps (Netflix, VUDU, HBO Go, Directv Now) on my Roku went from 5.1 to stereo.
I have an old Pioneer Elite VSX-33 which performs great, but is only capable of DD. No DD+. I'll have to update to a (at least) DD+ capable AVR, since sound is as important as the PQ to me.