Film-Tech Forum ARCHIVE: Sound format on Sat feeds

This is topic Sound format on Sat feeds in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=16;t=002775

Posted by Lindsay Morris (Member # 1430) on 08-08-2016, 03:16 AM:

I am curious as to how the sound is currently decoded out of the sat receiver.
Is it simply L & R stereo or do the current sat boxes drop out 5.1 or 7.1 sound.

I ask because I saw a sat feed screening recently at a cinema & the sound was awful...just L & R and NO centre & very thin sounding ..virtually NO bass component.

I would have thought that with modern day digital sat feeds the sound would be A1.

Posted by Steve Moore (Member # 4753) on 08-08-2016, 03:30 AM:

All the feeds that we receive here in the UK are Dolby 5.1 for our live shows; however what you hear will depend on the cinema. If they are still using old processors (such as CP55 for example) they may just be feeding the left and right output from the satellite receiver into the non-sync input.

Some of the sites I service refuse to upgrade from CP55 processors. When I have installed satellite I have fitted domestic optical 5.1 to 5.1 analogue converters and mixed the left and right surround together and mixed the sub in with the left and right channels (at low level). This is not my preferred choice; however some places refuse to upgrade their old audio kit.

Posted by Carsten Kurz (Member # 5396) on 08-08-2016, 04:13 AM:

Some programs carry both Stereo and 5.1 (AC3) streams, and you can select which of the two you prefer. For the live event transmission carried out into cinemas, I don't know wether they offer that selection.

- Carsten

Posted by Lindsay Morris (Member # 1430) on 08-09-2016, 01:15 AM:

Thanks for that.

Seems most likely that somebody in the bio box did not set up the sound patching correctly OR they simply did not have a ProLogic processor anymore.
I thought that with the current sat feeds now being predominantly digital rather than analogue that the AC3 stream would have been available & thus easy to extract the correct channels.

I have a VAST setup in my motorhome & the L & R sound is very good ..VAST is totally digital so I had also assumed that similar would apply to sat feeds for live shows. (VAST is an Aussie satellite system for people who cannot get access to terrestrial TV services & also has feeds into New Zealand. From it one can get every channel that is broadcast in the cities)

Even a simple L&R signal sent into a ProLogic unit gives VG sound anyway & in the venue I used to own to play any DVD or BluRay I sent the L&R straight into the CP650 & bingo good sound from all normal channels. So this very poor effort at this cinema really bothered me. [eyes]