Dd 5.1 Ex (1 Viewer)

[Scott W.]

Could Dolby Digital EX also be called DD 6.1? Cause isnt the 'EX' an extra 'centre rear' channel? Info would be appreciated. TIA!
Scott

 

[Chad Gregory]

It could only be called 6.1 if it was a seperate channel. It is called 5.1 because the rear center is matrixed into the other rears. Make sense? DTS-ES is 6.1 because of the seperation of the left rear, rear center and right rear into distinct channels.

There must be a better explanation than I'm giving, but you get the jist.

-Chad

 

[Michael Reuben]

Moving this to Receivers/Amps/Separates, where you'll find other discussions of audio formats.

Could Dolby Digital EX also be called DD 6.1?

Chad's explanation is right on the money. The "5" in "5.1" refers to five discrete channels of audio: left, right, center, left surround, rear surround. Dolby Surround EX does not have an additional discrete channel, so calling it "6.1" would be incorrect.
This hasn't stopped a lot of hardware makers from claiming that they make "6.1" and "7.1" receivers and processors. But technically, the only 6.1 format out there is DTS-ES 6.1 Discrete. And there is no -- repeat, zero -- 7.1 format at all.*
M.
*Unless you count SDDS-8, which is strictly for use in commercial theaters.

 

[Chad Gregory]

Michael,
Thanks, my mind went blank searching for the word "discrete".
-Chad

 

[Dan Hitchman]

Nothing new to add here, but I thought I'd post anyway.
Dolby Digital EX- 5.1 discrete channels, 1 matrix channel
DTS-ES Matrix- 5.1 discrete channels, 1 matrix channel
DTS-ES Discrete- 6.1 discrete channels (backwards compatible with DTS-ES Matrix and DTS 5.1 decoders).
Dan

 

[Marty Neudel]

>DTS-ES is 6.1 because of the seperation of the left rear, rear center and right rear into distinct channels.<

One small clarification: in ES-Discrete the left surround, right surround, and back channels are recorded independently, and not subject to later separation.

Remember that our perception of the location of sounds behind us is far less accute than for those in front of us. This most likely accounts for the results of double-blind tests conducted early in the developement of DD-EX that showed no difference in the perception of a discrete or matrixed back channel.

Relative to this, it is important to note that ES-Discrete mixes are optimized for decoding of the discrete back channel. Therefore, they sometimes offer less than ideal playback through the matrix decoder.

Marty

 

[Dan Hitchman]

Marty,

Having heard DTS-ES Discrete 6.1 tracks on proper DTS-ES decoding equipment, and their DD EX 5.1 counterparts, I have come to the conclusion that the discrete nature of the back surround channel in DTS-ES Discrete 6.1 encoded movies gives a much improved surround presentation.

The problem with DD-EX's use of a matrixed center back channel is the same as any ProLogic matrix encoding as subtle sound effects and less than perfect hard panned left and right positioned sound effects will tend to blob up into the center back channel where they aren't supposed to be. Multiple left-center-right and right-center-left panning are also smeered using a matrixed channel configuration.

Discrete is the only way to go.

Dan

 

[Marty Neudel]

Dan,
I was in a test group that spent a total of almost 10 hours (spread over 6 sessions), and we had not come across the artifacts you mentioned. Although, I can't remember any ES/EX mix with panning through the back channel. In fact, it was later explained to us that the back channel was located behind the listener while surround channel sound is placed beside the listener, therefore panning was not a normal procedure. Which films/segments did you find this situation in.
I think this really emphasizes the need for all of us to listen for themselves, using what we read as a guideline not as a 21st century gospel.
Marty

 

[John Tompkins]

Remember that our perception of the location of sounds behind us is far less accute than for those in front of us.

This may be true but using logic 7 on the lex which is the only 7.1 discrete "format" so to speak. The independent sounds coming from the BACK l/r speakers are very easily noticeable.