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Hi all

 

Is it safe to downmix from Dobly Pro Logic II to  Stereo ?

 

I've had had issues when playing video (m4v converted with Handbrake) on my Toshiba LCD internal speakers...

 

Its also the first time i've noticed Dolby Pro Logic on a DVD too, as I thought this was mostly for blue-ray ...aka Better quality, Better sound go together.
 

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Quote:
Originally Posted by TECH198  /t/1520049/dolby-pro-logic-ii#post_24414378


Is it safe to downmix from Dobly Pro Logic II to  Stereo ?
No it's dangerous! Don't do it! Just kidding


I use Pro Logic II @ 320 for my first audio track because it works well for both stereo and pro logic II 5.1. Set the second audio track to AC3 pass thru. This will give you the full 5.1 track when you stream through an Apple TV connected to a receiver with HDMI. Best of both worlds.
 

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Quote:
Originally Posted by TECH198  /t/1520049/dolby-pro-logic-ii#post_24414378


Hi all


Is it safe to downmix from Dobly Pro Logic II to  Stereo ?


I've had had issues when playing video (m4v converted with Handbrake) on my Toshiba LCD internal speakers...


Its also the first time i've noticed Dolby Pro Logic on a DVD too, as I thought this was mostly for blue-ray ...aka Better quality, Better sound go together.

First of all Dolby Pro Logic is older technology, not new. you'll find it on many early DVDs. Dolby Pro Logic takes stereo and converts to surround by manipulating the R/L channels to create the rears and center. The rears are mono (same info in each channel) so you won't get any rear left-to-right, or visa versa rear movement. The rears are also limited in their freq resp. (100Hz-7KHz ). I think this was originally done to reduce any interaction between the front and rear speakers. Works best with media specifically encoded for Dolby Pro Logic.


Dolby Pro Logic II improves on the original by deriving five (original DLP had four ch since the rear was mono) full-range channels. It sounds closer to 5.1. It also sounds good with encoded and non-encoded stereo sources.


So chances are you don't need to downmix the Dolby Pro Logic output, since it was originally stereo.
 

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Quote:
Originally Posted by TECH198  /t/1520049/dolby-pro-logic-ii#post_24414378


Hi all


Is it safe to downmix from Dobly Pro Logic II to  Stereo ?


I've had had issues when playing video (m4v converted with Handbrake) on my Toshiba LCD internal speakers...


Its also the first time i've noticed Dolby Pro Logic on a DVD too, as I thought this was mostly for blue-ray ...aka Better quality, Better sound go together.

What do you mean "I've had issues when playing video"? Dolby PLLII is chosen when you want to take a stereo format and simulate a 5.1 format, so what would be wrong with going back to stereo? What would be "Unsafe"?
 

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Quote:
Originally Posted by TECH198  /t/1520049/dolby-pro-logic-ii#post_24414378


Is it safe to downmix from Dobly Pro Logic II to  Stereo ?
If you don't process the signal Dolby is stereo.
 
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