Worthless TV Optical Out??
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New member Username: Gemineye111Post Number: 1 Registered: Nov-08 | I need help! I've been scouring the internet for answers and it seems I can't find any for an issue that seems to be EPIDEMIC in scale. I have Sony Bravia 40" LCD. Everything is hooked up via HDMI (except for that darn Wii which is component). In theory, the optical output going from TV to receiver should work. AND IT DOESN'T. No sound from my 360, ps3, or cable box. However, when I go through 2.0 channel (red and white cables) - the receiver outputs the sound (nothing connected to receiver except tv via optical). Isn't that worthless? Why have a digital jack that only passes analog sound? Even the instructions show a picture that label "PS3/Bluray player" hooked up to the TV via HDMI and with no additional cables, and then hooked up from TV to receiver using optical. The manual then states that the optical output is for outputting digital sound (DD5.1 and DTS). So why doesn't it? Please don't send me responses like "Your an idiot why don't you hook the sources up directly to the receiver." The answer is simple, my receiver has only 1 optical input, I'm using the TV to do all the HDMI switching (much like many other people with the same problem all over the web). If the TV can only output in 2.0 then why an optical out? It could have been handled cheaper with standard analog out. Right? My reciever is also Sony HTiB. I've read that TV optical out is useless, but others say they have my setup and works fine (...and they have BARGAIN HDTV Westinghouse and the like... why doesn't Sony's work?) What's WRONG?? |
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Silver Member Username: CclashhPost Number: 379 Registered: Jan-08 | I would say that it would be worth exploring the possibility that you have over looked something that is required in the setup of the Television meaning something in its "on screen display" that has to be configured in order to output sound the way you want. Can't be sure because you did not include the model number of the TV so I can't check the online manual. |
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Silver Member Username: MccambleyBREEZY POINT, NY USA Post Number: 538 Registered: Jun-05 | The optical out put on the TV is used ONLY for the ATSC (high def) tuner built into the TV. If you hook up a roof antenna to receive local high def station you can then send the Dolby digital signal that these channels supply to the receiver. This is the ONLY use for the Optical out put on TVs. TV can not act as switching stations for there inputs, only analog audio (red-white) can be out put from most TVs. Some Panasonics will allow analog video inputs (S-video and Composite) to be out put from other analog video out puts. There is NO digital out put from any digital in put. |
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Silver Member Username: CclashhPost Number: 380 Registered: Jan-08 | John S, or Jim Bay, John, Didn't you test this and get 5.1 this way on one of your TV's? I vaguely remember you posting something on this and that you had determined that this was possible. |
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Silver Member Username: CclashhPost Number: 381 Registered: Jan-08 | Casey, I guess I would have to strongly disagree with your statement. I found the thread with a post from John S. on using the TV optical out; It came from this Thread: https://www.ecoustics.com/electronics/forum/home-theater/489838.html Casey, even though you were a participant on that thread, you apparently did not read the results of an experiment I ran on one of my TVs. https://www.ecoustics.com/cgi-bin/bbs/show.pl?tpc=3&post=1545896#POST1545896 So I got audio from the optical output on some of the cable channels the display's QAM tuner picked up on my basic cable. My optical output showed DD 5.1 or 2.0 on all digital channels regardless of whether they were OTA or cable. I have read where some people have gotten audio on all cable channels via their TV's digital output on basic cable, even though it is hard to believe any TV would convert analog audio into digital audio and output it on its optical/coax jack. My point here is that I don't believe all TVs act the same way regarding their digital audio outputs, and I believe it is wrong to make a blanket generalization about them. In this instance, Bob is hoping his TV (of unknown brand/model) will route the digital audio coming in on HDMI from the cable box out via the TV's digital out. Who knows if that will work? I can guarantee you that, whatever the display in question, the owner's manual will be of no help in explaining what exactly the TV's digital output will or won't do. Whatever that reality is, I do agree with you that the best hookup is to use the cable box's audio output into the receiver. This would eliminate all doubt. My |
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Gold Member Username: John_sColumbus, Ohio US Post Number: 2359 Registered: Feb-04 | When someone sees an optical output on the back of their TV, who can blame them for assuming it will output digital audio regardless of the source? This is especially true when all Sony says about this output is "Connect to the optical audio input of your digital audio equipment that is PCM/Dolby Digital compatible." That's it. In a 50 page manual, no less. The truth is that the TV cannot decode any Dolby/DTS bitstream coming in on any of its HDMI inputs, and it also will not convert PCM coming in back to Dolby/DTS 5.1. So there's no digital audio output on the TV's optical out from HDMI sources (or any analog audio) going into it. I did not test any HDMI input on my TV. The only thing I proved is that my TV's QAM tuner will output digital audio on its optical output when the TV is hooked up to basic cable (and even then only with unencrypted digital channels). I would assume this applies to all QAM equipped TVs. And as Casey says, the optical out will also be functional on any digital TV signal received via over-the-air. The easiest and simplest solution to Len's problem is a simple 3 in/1 out optical switch like this: |
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Silver Member Username: CclashhPost Number: 382 Registered: Jan-08 | John, The reason I presented your previous post from the two corresponding threads was not based on any interpretation of your results but on direct statements you made in referrence to the possibility of someone being able to expect this to work. You said that generalizations on what the optical can do should not be formed and that obtaining disecrete audio in this manner cannot be ruled out. Am I mistaken? "My point here is that I don't believe all TVs act the same way regarding their digital audio outputs, and I believe it is wrong to make a blanket generalization about them." "In this instance, Bob is hoping his TV (of unknown brand/model) will route the digital audio coming in on HDMI from the cable box out via the TV's digital out. Who knows if that will work?" |
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Silver Member Username: MccambleyBREEZY POINT, NY USA Post Number: 539 Registered: Jun-05 | The only mistake I may have made with my blanket statement was how the TV deals with the QAM tuners' audio output. I am not sure but I think the QAM tuner acts a lot like the ATSC tuner in regards to the optical output. The point is that a TV will not act like a receiver and out put from the optical connection any digital or analog input from any other devise. |
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New member Username: Gemineye111Post Number: 2 Registered: Nov-08 | Thanks guys... I already figured I would have to purchase the Toslink splitter (works great btw). I contacted Sony about the problem and they don't know what's going on. First they said the digital out doesn't send the signal, then I pointed them to the quick setup guide picture "C" (KDL-40s4100 model) and they then looked it up, apologized for their ignorance and proceeded to walk me through my tv, HTiB, and PS3 settings after confirming that my thoughts were correct and that their manual was correct. They then offered me a brand new TV replacement and told me to send back the defect. Low and behold, the new TV comes in... NO DICE. Same problem. Thank goodness I came prepared and already ordered the Toslink splitter ahead of time. Thanks again guys. |
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Silver Member Username: CclashhPost Number: 383 Registered: Jan-08 | I have a question. We are establishing that the television is not capable of acting as a switching mechanism for the optical out. Based on intuition this does not seem to me as necessarily being the case. I do not believe that it is impossible and that we should be careful about making generalizations where this is concerned. While right now we are not finding this to be true it may be true at some future date. My question is why would it not be possible for the TV to act as a switching device because in essence all TV's have the capability of acting as a switch for their various inputs. Why would it be completely out of the question that the TV could pass the digital signal thru its optical out to the receiver based on the input you have selected on the TV? I do not think it to be prudent or fair to just tell anyone that asks this question that this is totally out of the question. Can we really say that it is electronically impossible? Is it really impossible for the manufacturer to include this feature in the design of the TV? Should a more careful examination of the potential for this to work be taken when this question is asked in the future? This is of course where the use of HDMI is concerned. |
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Silver Member Username: MccambleyBREEZY POINT, NY USA Post Number: 540 Registered: Jun-05 | Jeff you are correct in your thought process. But the same question can be asked of AV receivers. Why can't the receiver send digital audio to zone 2? You are forced to hook up analog connections from your source device to the receiver along with digital connections to use zone 2 or 3. Denon receivers will send optical and coaxial inputs to zone 2 on there new receivers but not with HDMI connections which is way we want to connect our devices today. If I want to use the video select option on the receiver to watch one thing but listen to another I can't do this if I am using an HDMI connection. I am sure someday this will all be worked out but for now it is the way it is. I don't know the reason for any of this but I will guess it is a cost factor. |
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Gold Member Username: John_sColumbus, Ohio US Post Number: 2360 Registered: Feb-04 | I have just completed a survey of user manuals for some of the major HDTV manufacturers. Current mid-line models were selected. There were certainly wide differences in information provided in these manuals concerning the digital audio outputs on these displays. Incidentally, I find it interesting that all TVs with ATSC tuners always had digital audio outs and that they were always optical and not coax. Anyway, here is a quick summary: SONY: We have already seen how foggy the issue is with them. As Len said, their "support" personnel are completely ignorant. They actually authorized a needless exchange of TVs. JVC: "No audio out on optical when using HDMI." TOSHIBA: "The DIGITAL AUDIO OUT terminal may not output some digital audio sources because of copy restrictions." PIONEER: "Note: When signals are input from the HDMI terminals, no signals are output from the DIGITAL OUT terminal if they are copy guarded. SAMSUNG: "[the digital terminal] outputs stereo only from HDMI sources." SHARP: "PCM audio outputs from the terminal." Elsewhere in the manual the implication is (sorry I don't have a direct quote here) that the optical output will pass Dolby Digital of all programs input -- tuner or HDMI. HITACHI: "This jack provides Digital Audio Output from a HDMI source or digital program channel to your audio device that is Dolby Digital and PCM compatible..." On the face of it, this issue should be considered on a case-by-case basis. Apparently, some displays will pass DD 5.1 from HDMI sources, and others won't. I could be wrong, but I still suspect that none of them will pass DD 5.1 unimpeded from any copy guarded source via HDMI due to the required HDCP protocols for a successful "handshake" between the TV and the source device. This copy guarded material includes many movie channels on cable and satellite, probably 90% of all DVDs, and all HD DVDs and Blu-rays. |
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Silver Member Username: MccambleyBREEZY POINT, NY USA Post Number: 541 Registered: Jun-05 | So from now on we will ask for a model number and look to see what this particular TV will do. But even doing this and after we read the TVs manual we still may not be clear how the optical output really works. |
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Silver Member Username: CclashhPost Number: 384 Registered: Jan-08 | Thanks Guys!! That is exactly the result I was anticipating and is the reason I presented my last post. John's findings are what I have been eluding to throughout this thread and that we should be verifying whether this is possible for each person that asks the question instead of just saying No its not possible. Thanks for all of your effort in this.... At least now we can be certain that we are providing accurate information on TV optical out! |
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Gold Member Username: John_sColumbus, Ohio US Post Number: 2361 Registered: Feb-04 | Here's more: SANYO: "Dolby Digital 5.1 audio is available at the Digital Audio Output only when received as part of a Digital Antenna signal being viewed on the screen." MITSUBISHI: "This output sends Dolby Digital or PCM digital audio to your A/V surround sound receiver. Analog audio from analog channels and devices is converted by the TV to PCM digital audio." Later Mitsubishi states that "...the TV's HDMI inputs can receive digital stereo signals only. To hear digital surround sound from an HDMI device, connect the device's HDMI or digital audio output directly to your A/V receiver." LG: "Digital Audio Output for use with amps and home theater systems." |
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Gold Member Username: John_sColumbus, Ohio US Post Number: 2362 Registered: Feb-04 | VIZIO: "When the DTV [cable/antenna] input is selected for viewing, the digital audio associated with digital programming will be available on this SPDIF Optical connector for connection to your home theater system." Later, "If your sound system has a SPDIF (optical) digital audio input you can connect it to the optical DIGITAL AUDIO OUT at the rear of [this TV]. This is active when receiving digital audio with the programs from the DTV/TV CABLE/ANTENNA input." |
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New member Username: MaryjPost Number: 1 Registered: Nov-08 | I have a low end Sony LCD (KDL-32L400) that will pass 5.1 from its HDMI in through its optical out. I have xbox 360 hooked to the tv with HDMI, toslink from the tv's optical out to optical/coax converter then coax hooked to Phillips theater in a box! I believe i am getting true 5.1, all speakers output sound when appropriate,(sounds behind or to the side of me seem to be where they should) tested a little with grenades in CoD, throw one and it lights up the front speakers and sub, throw one and turn around so it is behind my soldier and the speakers behind me explode as well as the sub rumble, with the front speakers keeping quiet. If I'm wrong please let me know cuz this is great to me and if it is not true I can only imagine how true 5.1 would be! |
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Gold Member Username: John_sColumbus, Ohio US Post Number: 2368 Registered: Feb-04 | Good for you Mary Jane. Sounds like you're getting 5.1 on games, but are you getting true DD 5.1 when you play a regular movie DVD on the xbox? |
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Silver Member Username: MccambleyBREEZY POINT, NY USA Post Number: 543 Registered: Jun-05 | I could not find that model on Sony's web site but they had the KDL-32L4000. Is it possible that Mary Jane is hearing PRO LOGIC not Dolby Digital. The manual says HDMI accepts Two Channel Linear PCM. If this is the case I don't see how you get Dolby Digital out from Optical. I also looked at the Hitachi and Samsung and they also only accept a stereo feed from HDMI and both recommend using a digital feed from source to receiver to get the proper set up. |
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New member Username: MaryjPost Number: 2 Registered: Nov-08 | Thanks Casey that was a typo the model you looked at is indeed mine. John, yes I am getting 5.1 from dvd, never bothered to check on that until now! I imagine this would not be true with hd-dvd due to the copy restrictions, but I most likely will not have the opportunity to try having not invested in that technology prior to it's defeat. So Casey, what you beleive I am hearing is pro logic? would pro logic give the results I had described? I apologize I am not very savvy in this realm of technology yet having not been able to afford any of it until recently! I have tried to do a little research for myself but am still confused... would you mind simplifying the difference between pro logic and dolby digital for me? I just don't understand what would be different as I am getting correct output from all channels as it is. I have another toslink on it's way and am ready to crack the case off my old 360 component cable to see if I can hear any difference hooked directly to the receiver. Thanks for the input, you guys are great! |
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Silver Member Username: CclashhPost Number: 385 Registered: Jan-08 | Mary, This is from another thread but it answers your question. What happens when you connect stereo cables to a surround sound system? As Casey indicated this is reffered to as Dolby Pro-logic. What happens is that the receiver takes the normally stereo signal and converts it as well as it can to 5.1 surround sound so you would hear sound coming from all 5 speakers and the subwoofer. The best way to describe why this is a disadvantage is to explain what true surround sound, dolby 5.1 or dts 5.1 is. True surround is delivered to the receiver as a digital signal (optical or coax) that can be decoded into the 5 channels and subwoofer meaning that each of the 5 speakers or channels is receiving their own unique sound or specific content. What this does is provide the most effective means of replicating the sound as it woud exist in reality. As you probably already know stereo can only provide unique sound to 2 channels or speakers. This limitation has to be compensated for by your receivers processor when dividing 2 channels into 5 and in that process a significant amount of sound quality is lost in comparison to true surround sound. In Summary Pro logic is converting stereo (or two channels) into surround sound (5 speakers + sub) and true surround actually has 5 different channels and a sub that each have there own unique sound coming from them. |
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Gold Member Username: John_sColumbus, Ohio US Post Number: 2371 Registered: Feb-04 | Mary Jane, Like all A/V receivers, most receivers in HTiB systems will indicate what's happening audio-wise. This is usually displayed either on the front panel of the receiver, or via on-screen display during playback. Since detailed front panel displays don't seem to be Philips' strong suit, I think you should be able to press a "display" button on the remote and see what is coming into the unit's digital input on your TV screen. I'm guessing that what you'll see is "2 channel" and that the receiver is defaulting to the digital surround sound matrix Dolby Pro-logic II. In my experience DPL II can sound like real Dolby Digital 5.1 with certain 2 channel signals. |
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New member Username: MaryjPost Number: 3 Registered: Nov-08 | Ok so I played around with the thing to make it tell me what it's getting and the results are surprising. The receiver is telling me it is indeed playing dolby digital with both games AND movies! the display on the front panel reads "Dolby Digital" for both, as well as digital broadcast channels, and dvd in the receiver itself. only when I tune to an analog tv station, or use the Wii does the receiver display "Dolby PLII". So does that solve this? I mean I know this is a junk receiver but it wouldn't lie to me, or would it?  |
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Silver Member Username: CclashhPost Number: 386 Registered: Jan-08 | John, Isn't it possible for the receiver to say Dolby Digital and still be 2.1? Shouldn't she be looking for Dolby Digital 3/2.1 or something like that or is that only true on 2.1 systems? I am asking because I have seen it both ways and I am not sure why it differs from one receiver to the other... I have seen 5.1 systems just say Dolby Digital and I have seen them say Dolby Digital 3/2.1... |
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Gold Member Username: John_sColumbus, Ohio US Post Number: 2374 Registered: Feb-04 | Jeff, it's possible that mary jane's receiver is simply indicating Dolby Digital without displaying the actual number of channels in that bitstream. Most regular AVRs will display not only "DOLBY DIGITAL", but also display the actual channels it is seeing. For example, my digital cable box sends Dolby Digital 2.0 to my receiver on a lot of channels and I can elect to listen to them in straight stereo or let my receiver default to DD PLII. Also I have some very early DVD releases that are DD 2.0. My copy of "A Few Good Men" (which was later re-released with full DD 5.1) is DD Stereo, encoded with Dolby Surround. Again, my receiver defaults to "DOLBY DIGITAL PLII: Movie". "Dolby Digital 5.1" and "Dolby Digital 3/2.1" are synonymous terms. But mary says she's getting discrete channels through her xbox signal fed into the TV via HDMI. Her test with the war game seems to confirm that. It is entirely possible that the TV downmixes DD 5.1 to PCM stereo for the display's internal speakers, while simultaneously sending the DD 5.1 bitsteam on its optical output. The real puzzle is if that's true with mary's Sony, why wouldn't Len's Sony do the same thing? Could there be differences in digital audio outputs with the same manufacturer? Very strange, if you ask me.
What possible motive would it have to lie to you mary jane? But now that you have called it "junk", it might just change its mind.  |
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Gold Member Username: John_sColumbus, Ohio US Post Number: 2376 Registered: Feb-04 | Or to put it more simply, if mary's receiver is showing "DOLBY DIGITAL" and it's only 2.0 or 2.1, then she would hear two channels only in the absence of a simulated digital surround matrix (like DPL II) kicking in. |
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