Getting a Samsung TV to output Dolby Digital 5.1 through OPT
Posted: Sun Jan 05, 2014 12:40 pm
Have a TV issue I'm hoping someone might be able to help with. Have crossposted this to a few AV-related forums in the hope that someone, somewhere might know what to do 
Excuse the long esssay, just wanted to document what I've learned, and what I've already tried.
My TV is a Samsung 55 Inch LCD TV(UA55ES6200) which I have connected to my AVR/Sound System(Logitech Z-5450) via an optical cable from the TV Optical Out. I also have a HTPC, PS3 and XBOX 360 all connected to the TV via HDMI. So basically, the connections look like this:
HTPC/PS3/XBOX360 -> HDMI cable -> TV -> Optical Cable -> AVR
What I'm looking for is for the TV to output Dolby Digital 5.1 surround sound to the AVR when the source is outputting a DD-encoded audio signal, whether that be from the TV OTA, HTPC, PS3 or XBOX. Currently when the source is connected via HDMI, it will only pass through stereo 2 channel PCM sound.
I know that in general, most TVs nowadays are documented to only pass through DD5.1 through the optical output if the source is coming from the internal OTA TV tuner and if the source is any other HDMI connected device, only 2 channel audio will be passed through the optical output. From what I can tell, this "feature" was introduced 2008/2009 as part of HDCP/HDMI agreements industry-wide, for reasons I'm not really sure of, but have seen copyright as a reason tossed around. There are TVs out there which have been found to pass through 5.1 audio signals natively through their optical out(http://reviews.cnet.com/8301-33199_7-57 ... sound-bar/) but unfortunately my TV doesn't seem to be one of them.
Even when TVs don't passthrough the 5.1 audio signal(and is documented in the manuals to not support 5.1 passthrough), people have found ways to "force" a 5.1 audio signal through, mainly by either by faking an EDID or ignoring the EDID. AFAIK, when the TV is connected to something via HDMI, it does some kind of HDMI handshake and it passes an EDID to the source device, which tells the source device what video and audio capabilities the TV has, which then governs what the source device will send to the TV. ie. if the TV tells the source device(eg. a PS3) that it can only accept 2 channel stereo audio, then the source device will only pass 2 channel stereo audio to it. This is what normally happens with my devices. If the TV tells the source device it can accept Dolby Digital 5.1/DTS, then the source device can send those signals to the TV. There are ways of faking an EDID(Gefen HDMI Detective, stuff like that)
With the PS3 and XBOX360, there are ways of ignoring the EDID being received from the TV, and just push the DD/DTS5.1 audio signal through(disabling Display Discovery on xbox, http://forums.astrogaming.com/showthrea ... -s-OPT-OUT), and others have reported success that when they pushed through the 5.1 signal to the TV, the TV would in turn passthrough the 5.1 signal to the AVR. As my particular TV is a samsung, I've been trying to see who else has had success with their Samsungs with this method, and I'm sure I've seen at least the following model years reported success: B, D, F. As mine is a E model year, I need to go through and do more research and see if anyone else had success with that year's models. As there are reported successes with earlier and later years Samsung models, I'm hoping this holds true in general with all Samsung TVs.
Now, I've tried the ignoring the EDID method for both the PS3 and XBOX360, and they sorta work but don't work fully... I've forced both game consoles to pass through DD5.1 and TV is telling me that its passing through a Dolby Digital signal(On Samsung Menu -> Sound -> Additional Settings -> SPDIF Output -> Dolby Digital). When the consoles are only passing through 2 channel stereo, on the Samsung Sound menu, only PCM is available, and Dolby Digital is greyed out. Once I force through DD5.1 on the consoles, both PCM and Dolby Digital is available. This is the same option on the TV that becomes available when the OTA TV Tuner detects a DTV signal with DD5.1, and when that happens the Logitech AVR successfully detects the DD5.1 signal and outputs 5.1 surround sound. However, when the XBOX/PS3 sends out the DD5.1 signal to the TV, and the TV says its passing through the DD5.1 signal, my Logitech AVR doesn't detect any signal coming and no sound gets played at all. This is what I don't get, from what I've done and what I can see on the consoles and TV, it should be working now.
At first I thought maybe an audio signal was being passed from the TV to the AVR properly, just the Logitech AVR wasn't recognising it. So I got a simple Samsung soundbar which supported DD5.1 and DTS, and connected that to the TV using the optical cable and checked it again. Same result, the Samsung soundbar didn't detect any audio signal coming in at all, same as the Logitech AVR. I've tried swapping different HDMI cables, optical cables as well and those didn't make any difference. This same setup used to work with a different TV that I've had since 2006(a noname Schaub Lorenz), and passed the DD5.1 signals through fine. Unfortunately, I had to retire that TV a year ago due to panel issues
so have been trying to get this working with the replacement Samsung TV ever since.
Any suggestions/hints?
Some answers to the inevitable questions coming:
1) My current Logitech AVR does not support HDMI, so I can't just route all the source device HDMIs to go through the AVR first, then go from the AVR to the TV.
2) Am sticking with the Logitech AVR for now, as it has wireless rears which works well enough in my apartment where its too hard to route speaker cables to rear speakers. Also, I'm no audiophile, so I don't need a Denon or Onkyo, I just want 5.1 surround sound.
3) I'd like to use the TV as the main switcher, so that regardless of what input source the TV is using, the matching audio will be piped to the AVR, without me having to also change the input source on the AVR to match input source on the TV. Also, this XBOX360 that I have, is a E version, which has no optical output, it only outputs DD5.1 through the HDMI output so if I want 5.1 surround sound from my xbox, I need to get this working.
Excuse the long esssay, just wanted to document what I've learned, and what I've already tried.My TV is a Samsung 55 Inch LCD TV(UA55ES6200) which I have connected to my AVR/Sound System(Logitech Z-5450) via an optical cable from the TV Optical Out. I also have a HTPC, PS3 and XBOX 360 all connected to the TV via HDMI. So basically, the connections look like this:
HTPC/PS3/XBOX360 -> HDMI cable -> TV -> Optical Cable -> AVR
What I'm looking for is for the TV to output Dolby Digital 5.1 surround sound to the AVR when the source is outputting a DD-encoded audio signal, whether that be from the TV OTA, HTPC, PS3 or XBOX. Currently when the source is connected via HDMI, it will only pass through stereo 2 channel PCM sound.
I know that in general, most TVs nowadays are documented to only pass through DD5.1 through the optical output if the source is coming from the internal OTA TV tuner and if the source is any other HDMI connected device, only 2 channel audio will be passed through the optical output. From what I can tell, this "feature" was introduced 2008/2009 as part of HDCP/HDMI agreements industry-wide, for reasons I'm not really sure of, but have seen copyright as a reason tossed around. There are TVs out there which have been found to pass through 5.1 audio signals natively through their optical out(http://reviews.cnet.com/8301-33199_7-57 ... sound-bar/) but unfortunately my TV doesn't seem to be one of them.
Even when TVs don't passthrough the 5.1 audio signal(and is documented in the manuals to not support 5.1 passthrough), people have found ways to "force" a 5.1 audio signal through, mainly by either by faking an EDID or ignoring the EDID. AFAIK, when the TV is connected to something via HDMI, it does some kind of HDMI handshake and it passes an EDID to the source device, which tells the source device what video and audio capabilities the TV has, which then governs what the source device will send to the TV. ie. if the TV tells the source device(eg. a PS3) that it can only accept 2 channel stereo audio, then the source device will only pass 2 channel stereo audio to it. This is what normally happens with my devices. If the TV tells the source device it can accept Dolby Digital 5.1/DTS, then the source device can send those signals to the TV. There are ways of faking an EDID(Gefen HDMI Detective, stuff like that)
With the PS3 and XBOX360, there are ways of ignoring the EDID being received from the TV, and just push the DD/DTS5.1 audio signal through(disabling Display Discovery on xbox, http://forums.astrogaming.com/showthrea ... -s-OPT-OUT), and others have reported success that when they pushed through the 5.1 signal to the TV, the TV would in turn passthrough the 5.1 signal to the AVR. As my particular TV is a samsung, I've been trying to see who else has had success with their Samsungs with this method, and I'm sure I've seen at least the following model years reported success: B, D, F. As mine is a E model year, I need to go through and do more research and see if anyone else had success with that year's models. As there are reported successes with earlier and later years Samsung models, I'm hoping this holds true in general with all Samsung TVs.
Now, I've tried the ignoring the EDID method for both the PS3 and XBOX360, and they sorta work but don't work fully... I've forced both game consoles to pass through DD5.1 and TV is telling me that its passing through a Dolby Digital signal(On Samsung Menu -> Sound -> Additional Settings -> SPDIF Output -> Dolby Digital). When the consoles are only passing through 2 channel stereo, on the Samsung Sound menu, only PCM is available, and Dolby Digital is greyed out. Once I force through DD5.1 on the consoles, both PCM and Dolby Digital is available. This is the same option on the TV that becomes available when the OTA TV Tuner detects a DTV signal with DD5.1, and when that happens the Logitech AVR successfully detects the DD5.1 signal and outputs 5.1 surround sound. However, when the XBOX/PS3 sends out the DD5.1 signal to the TV, and the TV says its passing through the DD5.1 signal, my Logitech AVR doesn't detect any signal coming and no sound gets played at all. This is what I don't get, from what I've done and what I can see on the consoles and TV, it should be working now.
At first I thought maybe an audio signal was being passed from the TV to the AVR properly, just the Logitech AVR wasn't recognising it. So I got a simple Samsung soundbar which supported DD5.1 and DTS, and connected that to the TV using the optical cable and checked it again. Same result, the Samsung soundbar didn't detect any audio signal coming in at all, same as the Logitech AVR. I've tried swapping different HDMI cables, optical cables as well and those didn't make any difference. This same setup used to work with a different TV that I've had since 2006(a noname Schaub Lorenz), and passed the DD5.1 signals through fine. Unfortunately, I had to retire that TV a year ago due to panel issues
so have been trying to get this working with the replacement Samsung TV ever since.Any suggestions/hints?
Some answers to the inevitable questions coming:
1) My current Logitech AVR does not support HDMI, so I can't just route all the source device HDMIs to go through the AVR first, then go from the AVR to the TV.
2) Am sticking with the Logitech AVR for now, as it has wireless rears which works well enough in my apartment where its too hard to route speaker cables to rear speakers. Also, I'm no audiophile, so I don't need a Denon or Onkyo, I just want 5.1 surround sound.
3) I'd like to use the TV as the main switcher, so that regardless of what input source the TV is using, the matching audio will be piped to the AVR, without me having to also change the input source on the AVR to match input source on the TV. Also, this XBOX360 that I have, is a E version, which has no optical output, it only outputs DD5.1 through the HDMI output so if I want 5.1 surround sound from my xbox, I need to get this working.