Mpeg/PCM vs Dolby setting?

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HDslave

9 posts

Wannabe Geek

#41833 23-Sep-2009 17:01

Just wondered what eveyone uses when watching HD movies for best surround sound.

When watching Transformers HD I tried the setting at Mpeg/Pcm and it seemed, louder/gruntier, but the surrounds didnt seem to work, well they worked but more like in mono.

Switching back to Dolby and the surrounds seemed to work just fine, (sound whizzing round etc).

I tried optical and the same thing happened, now running through hdmi. I was mainly curious if this is a sky thing with the pcm setting or something else?

Thanks in advance.

andrewcnz

933 posts

Ultimate Geek

#257911 23-Sep-2009 19:29

You need to set the sky box(my sky HDi) to Dolby Digital to get true 5.1 surround sound and you need to use the coax or optical connection from the sky box to the amp. Audio via the HDMI connection is stereo only.

hairy1

2936 posts

Uber Geek

Trusted

Lifetime subscriber

#257915 23-Sep-2009 19:45

Switching between Dolby and PCM is now an option on HDMI with the new firmware of a couple of days ago. It is an extra option in the audio settings. Cheers, Matt

My views (except when I am looking out their windows) are not those of my employer.

andrewcnz

933 posts

Ultimate Geek

#257918 23-Sep-2009 19:56

hairy1: Switching between Dolby and PCM is now an option on HDMI with the new firmware of a couple of days ago. It is an extra option in the audio settings. Cheers, Matt

I stand corrected will go and gave a look... yes I see. Well that will help those who cable HDMI though a receiver.

Edit :Typo

HDslave

9 posts

Wannabe Geek

#257961 24-Sep-2009 06:37

Thanks guys. I had noticed the hdmi audio setting had only been added very recently.

So for 5.1 surround the best option is the dolby setting then? When set in dolby, HD channels come through as dolby digital 3/2.1, but when switched to mpeg/pcm all chanels come through as pcm 48.

So long story short, is the dolby setting the best one? Thanks again.

andrewcnz

933 posts

Ultimate Geek

#258096 24-Sep-2009 15:40

Well if you want true 5.1 then Dolby digital is the way.

DS9

299 posts

Ultimate Geek

Lifetime subscriber

#258820 27-Sep-2009 23:07

Since the firmware update I have found that my sound is out of sync, I am using My SKY HDi - HDMI - (LG 42LH50YD) LCD TV and the sound is ahead of the picture, has anyone else noticed? I see you can delay the optical but not the HDMI, I am not sure what to do.

I aim to misbehave.

login

171 posts

Master Geek

#260568 2-Oct-2009 14:04

I watched "The Incredible Hulk" in Dolby digital 5.1 last night. It's really impressive since the MySkyHDi firmware upgrade of 21/22 Sept. It blew the cat away! My wife (upstairs sewing) thought it was a big earthquake coming.

vexxxboy

3234 posts

Uber Geek

#261588 6-Oct-2009 11:47

can anyone tell me why i cant change the setting, at the moment its set to PCM but when i change it to dolby my amp picks up its dolby, as the blue light goes on and the sound changes, but soon as i leave the menu it changes back.anyone know why, I have a Sony 7:2 home theatre system is that the reason ?

....................nevermind fixed it

Common sense is not as common as you think.

clevedon

1051 posts

Uber Geek

#261699 6-Oct-2009 14:30

vexxxboy: can anyone tell me why i cant change the setting, at the moment its set to PCM but when i change it to dolby my amp picks up its dolby, as the blue light goes on and the sound changes, but soon as i leave the menu it changes back.anyone know why, I have a Sony 7:2 home theatre system is that the reason ?

....................nevermind fixed it

Ha ha, stupid save tab hidden way down the bottom. Been there, done that.

clevedon

1051 posts

Uber Geek

#262028 7-Oct-2009 13:08

I guess there is no advantage in removing the optical cable, even now that DD runs through HDMI other than one less cable, is there?

vexxxboy

3234 posts

Uber Geek

#262051 7-Oct-2009 14:07

after changing to dolby , i can no longer change the volume with my sky remote through my amp which i could when it was set to PCM, anyone know why

Common sense is not as common as you think.

rhysb

431 posts

Ultimate Geek

Trusted

#262068 7-Oct-2009 14:53

vexxxboy: after changing to dolby , i can no longer change the volume with my sky remote through my amp which i could when it was set to PCM, anyone know why

AC3 is an encoded bit stream, so to change the volume you would have to decode it, change the volume, then re-encode it again. Each time it is re-encoded would also result in quality loss, so generally the AC3/DTS streams are passed through unmolested.