How is 7.1 downgraded to 5.1? - Blu-ray Forum

Korrigan · 10-20-2013, 02:58 PM

A question to the audio experts of the website...

When you only have a 5.1 speaker system plugged to your Receiver, how is 7.1 (or even 6.1) audio downgraded? Are the two additional channels completely lost, or are they mixed into the two surround speakers so that no audio information is lost?

Just curious.

chip75 · 10-20-2013, 03:03 PM

Quote:

Originally Posted by Korrigan

A question to the audio experts of the website...

When you only have a 5.1 speaker system plugged to your Receiver, how is 7.1 (or even 6.1) audio downgraded? Are the two additional channels completely lost, or are they mixed into the two surround speakers so that no audio information is lost?

Just curious.

I think the sound information is just sent to the four surrounds (when applicable) with no loss. I'm sure it's the same when you go to 2.1, 2.0 et cetra you just have less sound separation due to less speakers.

mastadge · 10-20-2013, 03:15 PM

What I remember of my understanding of these things (which may be completely wrong) is that the sound is always sent out in two streams, which your technology then splits properly to the various speakers, so when you have speakers there's no need for them to figure out what to mix -- they just don't split the signals.

BIslander · 10-20-2013, 03:37 PM

There's metadata in codecs like TrueHD and dts-MA that controls downmixing so that nothing is lost when the playback system has fewer speakers than the source material. The rear channels are downmixed to the surround channels when 7.1 is played on a 5.1 system. When the source material is PCM, the software in the player or receiver will handle the downmixing so that nothing is lost.

GaragePoet · 10-20-2013, 04:00 PM

that would really be a pain for people w/ a minimal audio set-up, playing a 7.1 mix thru 2 speakers. they wouldn't be able to hear most of what's going on!

BIslander · 10-20-2013, 04:20 PM

??

7.1 content will be properly downmixed for stereo. Nothing gets discarded.

Almadacr · 10-20-2013, 04:22 PM

Quote:

Originally Posted by BIslander

??

7.1 content will be properly downmixed for stereo. Nothing gets discarded.

But i guess he is talking about not having surround sound and with 2 speakers you don't have the same feeling .

bhampton · 10-20-2013, 09:06 PM

Answer - exactly like native 5.1

Dolby downmix.

10-20-2013, 02:58 PM	#1
Korrigan Member Top contributor Member since:Sep 2011 Location:Planet Earth 4K collection:2 Blu-ray collection:341 Blu-ray reviews:18	How is 7.1 downgraded to 5.1? A question to the audio experts of the website... When you only have a 5.1 speaker system plugged to your Receiver, how is 7.1 (or even 6.1) audio downgraded? Are the two additional channels completely lost, or are they mixed into the two surround speakers so that no audio information is lost? Just curious.

10-20-2013, 03:15 PM	#3
mastadge Expert Member Member since:Aug 2012 4K collection:19 Blu-ray collection:952 DVD collection:8	What I remember of my understanding of these things (which may be completely wrong) is that the sound is always sent out in two streams, which your technology then splits properly to the various speakers, so when you have speakers there's no need for them to figure out what to mix -- they just don't split the signals.

10-20-2013, 03:37 PM	#4
BIslander Blu-ray Samurai Member since:Sep 2008 Location:Bainbridge Island, WA	There's metadata in codecs like TrueHD and dts-MA that controls downmixing so that nothing is lost when the playback system has fewer speakers than the source material. The rear channels are downmixed to the surround channels when 7.1 is played on a 5.1 system. When the source material is PCM, the software in the player or receiver will handle the downmixing so that nothing is lost.

10-20-2013, 04:00 PM	#5
GaragePoet Blu-ray Samurai Top contributor Member since:Sep 2011 Location:San Diego 4K collection:434 Blu-ray collection:1713 DVD collection:168 Trading Score:84	that would really be a pain for people w/ a minimal audio set-up, playing a 7.1 mix thru 2 speakers. they wouldn't be able to hear most of what's going on!

10-20-2013, 04:20 PM	#6
BIslander Blu-ray Samurai Member since:Sep 2008 Location:Bainbridge Island, WA	?? 7.1 content will be properly downmixed for stereo. Nothing gets discarded.

10-20-2013, 09:06 PM	#8
bhampton Blu-ray Count Member since:Aug 2007 4K collection:982 Blu-ray collection:2538 DVD collection:67 Blu-ray reviews: 6 Trading Score:18	Answer - exactly like native 5.1 Dolby downmix.

Best iTunes Music Deals