Problems with Dolby Digital 5.1 surround sound on Freeview HD – the facts
If you've recently invested in a new Freeview HD telly or set-top box, you're probably enjoying the World Cup in high definition.
But while you may be getting HD pictures, you may not be getting Dolby Digital 5.1 surround sound.
Why? Because it transpires that not all the Freeview HD TVs and set-top boxes currently on sale are capable of transcoding the multichannel audio signal being broadcast by the BBC on its HD programmes.
It's all to do with the fact that the Beeb has to provide an audio description service on BBC HD, and to do this it has to use the AAC audio codec present in Freeview HD receivers, rather than Dolby Digital.
Hence the main audio is coded as AAC-LC and the audio description as HE-AAC, because the main audio soundtrack and the audio description must use the same encoding family, as explained in this BBC blog by Phil Layton, project manager Digital Service Development, BBC R&D.
So why does this matter? Well, put simply, not all current Freeview HD TVs and set-top boxes can transcode from the AAC format to Dolby Digital so that your current AV equipment will be able to understand it.
According to the Beeb, transcoding will only become mandatory in all Freeview HD products after April 2011, which means there may well be confusion for a while to come.
With that in mind, we've undertaken our own research to find out which Freeview HD products do transcode and output Dolby Digital 5.1 via a digital connection to a home cinema amp/receiver, and which do not, so here are the results:
Goodmans GDB300HD - no
Humax HD-FOX T2 - yes (with this software upgrade)
Icecrypt T2200 - no
Digital Stream DHR8202U - no
Panasonic TX-L37V20 TV - no
Panasonic TX-L37S20 TV - no
Panasonic TX-P46G20 - no
Philips DTR5520 - no
Philips HDT8520 - no
Linsar FHD1 - yes
LG 32LE7900 - yes
Panasonic TX-L32D25 - no
Panasonic TX-l32S20 - no
Samsung UE32C6000 - yes
Sharp LC-32DH510 - no
Sony KDL-32EX503 - yes
Sony KDL-32EX703 - yes
Sony KDL-46EX503 TV - yes
Sony KDL-37EX503 TV - yes
Sony KDL-46HX703 - yes
Toshiba 32RV753 - yes
Toshiba 32SL753 - yes
Samsung UE37C6505 TV - yes
LG 37LE5900 TV - yes
Thanks to professorhat for this exhaustive thread on our Forums in which he tests the Philips DTR8520 and finds it does not output 5.1 sound (among other problems).
If you've recently bought a Freeview HD TV or receiver and are having trouble getting it to output Dolby Digital, please let us know in the Comments box below. We'll add more products to our own list as soon as we test them.
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Comments
I have a Sony DL-40EX503 and an Onkyo TX-NR808 AV receiver. With this combination I was able to watch indiana jones and the kingdom of the crystal skull, and Wallace and Gromit in Dolby Digital 5.1 from the BBC One HD channel. With the Onkyo switching successfully between DD5.1 and two channel sound.
The situation may not be consistent but it is getting there.
Keep watching!!
I can get dolby digital 5.1 on my old Humax Freesat HD box but not on my new Samsung 46" 650 (6 series) with Freeview HD. I gather that updates may be available but can't find any information.
Just for further clarification, Panasonic has confirmed that NONE of the company's 2010 TVs will output 5.1 from Freeview HD, and that this will NOT be enabled with future firmware.
The 2011 TVs will output 5.1 from Freeview HD, though.
It's a different case with Freesat, though: all of Panasonic's Freesat TVs will automatically output 5.1 via optical or HDMI ARC when you switch the satellite tuner to an appropriate HD broadcast.
Some info on Panasonic 42TXG20B I connected a fibre optic cable to the SPDIF on the TV to a Sony AV Amp.
Freesat Dolby 5.1 > SPDIF > Dolby 5.1
HDMI In Dolby 5.1 > SPDIF > PCM 48
HDMI In DTS 5.1 > SPDIF > PCM 48
HD on USB Dolby 5.1 > SPDIF > Dolby 5.1
I have a new Panasonic 42TXG20B with Freeview HD and Freesat HD. I can only get HD via Freesat in my area. I have been having this strange audio problem with BBC HD programmes. I thought I was going to have to send the TV back until I read your article.
The sounds seems to fade up and down especially the centre channel with any Dolby broadcast. I can enable Audio description which solves the problem but add extra (unwanted) description to the soundtrack.
No, 5.1 capability wouldn't make a huge difference as you're using a 2.1 system and therefore don't have a full 5.1 set-up to feed the DD5.1 signal to.
And AFAIK, none of the current Panasonic TVs handle DD5.1 on Freeview HD.
Thanks Andy. Panasonic confirm no upgrades or firmware adjustments are planned for the TX-L37S20B . Do you know which current Panasonic LCD sets ARE compliant with the Freeview Dolby 5.1 system? I am using the set with a Panasonic 2.1 SA- BT222 BluRay system (I want to keep the number of speakers to a minimum). Given this sound set up, would 5.1 capability via the set's FREEVIEW make any difference anyway? Thanks for any help.
It's possible Panasonic could provide an upgrade, but I have no knowledge of one at the moment.
I have recently purchased a Panasonic 37" LCD Model TX-L32S20B which apparently does not decode Dolby 5.1 through Freeview. Does this mean it can NEVER decode Dolby or is it possible that Panasonic will release a firmware upgrade? I have just ordered a Panasonic SC-BT222EB-K Blu Ray player-speaker set (2.1). Will this device decode through Freeview and pass on the correct signal to the TV? Sorry, I am not too technically aware. Thanks for any help.
I don't know about the surround audio test as I haven't used it (although it should), but when listening to BBC HD broadcasts with DD 5.1 surround sound on my home system I certainly get a separate LFE signal, yes.
Thanks for your reply Andy, so are you saying that the surround audio test on BBC HD should output the subwoofer channel when indicated on the screen because I certainly get no sound when it switches to LFE?
I was about to buy a Freview HD PVR but will certainly not do so until I can be sure it will output 5.1.
No, colini, the Humax Foxsat HDR is a Freesat device, a totally different system from Freeview HD. You should be able to get surround sound on BBC HD programmes broadcast with a DD 5.1 soundtrack (not all are).
Is this why my Humax Foxsat-HDR never delivers the .1 subwoofer output when viewing the BBC HD test card/audio? The 5. channels are all present and delivered where expected.
No, you can't make any assumptions about that. I've not seen any Freeview HD kit without an S/PDIF output, and plenty can only use that - whether optical or co-axial - to produce stereo, rather than Dolby Digital 5.1
You will only get DD 5.1 if the equipment can transcode, and it's not mandatory until April next year for it to do so.
...looking at basics, if the Freeview HDTV has a DIGITAL OPTICAL and/or DIGITAL COAXIAL output, then can we assume it provides Dolby Digital 5.1?.
(If there are only component(Phono) audio output connections, then the TV isn't designed to give 5.1!.)
the panasonic tx-p42g20 plasma does not output 5.1 from freeview hd, however it does output 5.1 from luxe tv hd via the dvbs tuner.
Thank you professohat and WHF. Very useful to know when you are on the market for a FWHD box!
Or to put it another way, Jamct69, stereo. ITV isn't outputting Dolby Pro-Logic - the sound is in stereo, and your amp is attempting to process it with PL.
..ITV1-hd doesn't even transmit Dolby Digital via any platform yet!.
I have my Virgin Media V+ HD box audio set to cut-off the TV speakers and output DD via digital optical lead to my amp' when watching any HD channel. All do so except ITV which outputs Dolby ProLogic to both Amp and TV speakers.
Any news on the KDL-40NX703?
The Samsung UE46C8000 outputs 5.1 sound.