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#336765 - 06/09/2010 02:58 Home theater help: HDMI pass through 5.1 surround to optical?
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31597
Loc: Seattle, WA
I just got a new TV set, an LG 55LE5400 model. It's theoretically supposed to support HDMI 1.3. It has four HDMI inputs, and a digital audio optical output.

My theory was that I could use this TV to obtain all the audio from my HDMI-connected devices via their HDMI cables, and then use its single digital audio optical output to send the digital audio to my AV receiver. In other words, no more fiddling with a billion audio cords in the back of my AV receiver (which had too-limited audio input capability anyway), and now everyone would send their full range digital audio, via the TV's input selector, to a single optical input on the AV receiver.

However, with my devices, when I select them on the TV, I only get stereo digital audio through the TV to the AV receiver. Example: Placing a 5.1 surround DVD into the Playstation 3, the AV receiver shows only two channel stereo digital audio, the little 5.1 channel indicators do not light up.

If I were to connect the device directly to the AV receiver via its optical audio cable, I would get 5.1. However my AV receiver doesn't have enough inputs for me to do that with all the devices I want to do it with, so I was hoping the TV would solve that problem for me.

Anyway, I thought I could do this stuff with HDMI 1.3. Am I asking too much of the system to do this?
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Tony Fabris

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#336766 - 06/09/2010 03:03 Re: Home theater help: HDMI pass through 5.1 surround to optical? [Re: tfabris]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31597
Loc: Seattle, WA
By the way, I dug through the TV's settings screens. There's nothing there to control this. I've got the TV's internal speaker turned off so that I only hear the AV receiver, and all the menus are grayed out. Even if I turn on the internal speaker, the only options are for things like bass and treble and dynamic range control, nothing to control HDMI audio pass through.
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Tony Fabris

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#336767 - 06/09/2010 03:50 Re: Home theater help: HDMI pass through 5.1 surround to optical? [Re: tfabris]
Shonky
pooh-bah

Registered: 12/01/2002
Posts: 2009
Loc: Brisbane, Australia
The optical output on TVs is only intended for the inbuilt TV tuner. They have never been intended for audio pass through.

It just so happens that some TVs (Panasonic are one I know for sure that do, the old Pioneers didn't) pass through some audio. It's not always exactly what goes in the HDMI port though.

What you are finding is that the TV is probably converting the 5.1 audio via the HDMI to two channel for its stereo speakers. It's then passing that two channel stream back out the optical port. You're lucky it's doing that - some TVs don't send anything but output from the inbuilt tuner.

They seem to work surround sound wise and most receivers seem to pick up the audio as old Prologic type surround sound. I've never used it long enough to determine if the surround is still working. You obviously lose the 5.1 discrete channels though.

Also note that optical SP/DIF type connections cannot carry the newer audio formats like DTS-HD MA or Dolby True HD. It's possible the TV couldn't handle them either.

It's not a fault of HDMI 1.3. It's not really a fault of anything. It's simply that the HDMI audio doesn't get stripped straight off and sent to the optical out. There may even been HDMI HDCP issues with doing that and obtaining the raw audio stream unencrypted.

So yes, you are expecting too much unfortunately. frown
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Christian
#40104192 120Gb (no longer in my E36 M3, won't fit the E46 M3)

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#336769 - 06/09/2010 05:59 Re: Home theater help: HDMI pass through 5.1 surround to optical? [Re: Shonky]
MarkH
member

Registered: 06/04/2000
Posts: 158
I believe you would need to stick something like this just before the TV

Gefen simple converter

or spend big money on something like

Gefen multi-channel converter

Note that the simple one can only handle two channel which means all your HDMI sources would have to be set to 2-ch downmix output for all the reasons Shonky describes above.

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#336770 - 06/09/2010 07:05 Re: Home theater help: HDMI pass through 5.1 surround to optical? [Re: MarkH]
Dignan
carpal tunnel

Registered: 08/03/2000
Posts: 12338
Loc: Sterling, VA
Sorry to hear that, Tony. This is why my next purchase, instead of a new TV, will be a new receiver. That way I'll have all the HDMI coming into the receiver, where all the audio can be handled, and have a single cable to the TV. That will keep all the cabling low and out of the way (with zip ties everywhere), and make it so that the TV can sit on one input and I'll change the input on the receiver instead.

Currently, I have an HDMI switch from Monoprice (they no longer sell it but this is a similar device *edit*oops, looks like they don't sell the one with the TOSLINK in it anymore*/edit*). All my devices go into it. But it also has a handy optical out in addition to the HDMI out. I connect that to my receiver now, which gets me part of the way there.

The only annoyance now is that there seems to be some issues with the audio output of my bluray player when it gets to my old receiver. I guess it's just that the old equipment doesn't understand some of the new standards, and occasionally I get weird things like no dialog (but I get the rest of the audio). Once I fiddle with the bluray player's settings it works, though.


Edited by Dignan (06/09/2010 07:08)
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Matt

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#336771 - 06/09/2010 08:42 Re: Home theater help: HDMI pass through 5.1 surround to optical? [Re: Dignan]
Shonky
pooh-bah

Registered: 12/01/2002
Posts: 2009
Loc: Brisbane, Australia
There is one significant advantage to running the devices direct to the TV. Most TVs these days remember settings on a per input basis so you can individually calibrate your sources for best picture quality.

Having a receiver then requires an extra remote so by then you are considering at a universal remote of some description. They really are worth it for WAF though. I can go away for work and my girlfriend doesn't have any issues while I'm gone. The help function fixes things if something gets out of sync.
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Christian
#40104192 120Gb (no longer in my E36 M3, won't fit the E46 M3)

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#336774 - 06/09/2010 11:29 Re: Home theater help: HDMI pass through 5.1 surround to optical? [Re: Shonky]
hybrid8
carpal tunnel

Registered: 12/11/2001
Posts: 7738
Loc: Toronto, CANADA
Use can use a DVDO Edge as a video switcher, then you have your individual input settings, including color calibration, along with video scaling and of course digital audio passthrough (on HDMI and toslink).

Approximate cost: $450-$500.
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Bruno
Twisted Melon : Fine Mac OS Software

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#336775 - 06/09/2010 11:44 Re: Home theater help: HDMI pass through 5.1 surround to optical? [Re: Shonky]
Dignan
carpal tunnel

Registered: 08/03/2000
Posts: 12338
Loc: Sterling, VA
Originally Posted By: Shonky
There is one significant advantage to running the devices direct to the TV. Most TVs these days remember settings on a per input basis so you can individually calibrate your sources for best picture quality.

Having a receiver then requires an extra remote so by then you are considering at a universal remote of some description. They really are worth it for WAF though. I can go away for work and my girlfriend doesn't have any issues while I'm gone. The help function fixes things if something gets out of sync.

So do you not have a receiver at all? What is your speaker setup like?

I do have a universal remote, and my wife has zero problems with the home theater because I have the remote set up so that it cannot fail. I LOVE discrete codes!
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Matt

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#336779 - 06/09/2010 14:23 Re: Home theater help: HDMI pass through 5.1 surround to optical? [Re: tfabris]
drakino
carpal tunnel

Registered: 08/06/1999
Posts: 7868
The PS3 may be able to help confirm the situation here. Go under Settings, Display Settings, then select Video Out settings. Go past the video setup, then select Automatic for HDMI sound. This should report back what types of signals the TV is willing to accept.

Sadly the problem is likely what Shonky said though. Most TVs will not reroute surround sound coming from HDMI out to another device.

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#336783 - 06/09/2010 17:28 Re: Home theater help: HDMI pass through 5.1 surround to optical? [Re: drakino]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31597
Loc: Seattle, WA
Yeah, this is definitely a case of the TV only converting the HDMI audio to stereo, and not passing it along to the output in the daisy chain. That kind of sucks.

I'm able to 5.1 digital audio on a few of my devices by routing their optical and coax digital outputs directly to the stereo. The problem is that the stereo doesn't have enough inputs to do them all. So a couple of my devices, I only get stereo instead of getting 5.1. Ah well.
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Tony Fabris

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#336784 - 06/09/2010 18:17 Re: Home theater help: HDMI pass through 5.1 surround to optical? [Re: tfabris]
hybrid8
carpal tunnel

Registered: 12/11/2001
Posts: 7738
Loc: Toronto, CANADA
Hmm.. I have an insane number of digital connections on my Pre-Amp and only two digital sources. I suppose it's the reverse problem. smile
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Bruno
Twisted Melon : Fine Mac OS Software

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#336785 - 06/09/2010 19:28 Re: Home theater help: HDMI pass through 5.1 surround to optical? [Re: tfabris]
tanstaafl.
carpal tunnel

Registered: 08/07/1999
Posts: 5549
Loc: Ajijic, Mexico
Originally Posted By: tfbris
the stereo doesn't have enough inputs to do them all.
I take it, then, that you can't just use a splitter like on a telephone line when you want to share the phone with a fax or something? That way you could run several different devices into a single input as long as only one of them was actually operating. Would it cause signal path problems with feedback or something?

tanstaafl.
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"There Ain't No Such Thing As A Free Lunch"

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#336786 - 06/09/2010 19:32 Re: Home theater help: HDMI pass through 5.1 surround to optical? [Re: tanstaafl.]
tman
carpal tunnel

Registered: 24/12/2001
Posts: 5528
Originally Posted By: tanstaafl.
I take it, then, that you can't just use a splitter like on a telephone line when you want to share the phone with a fax or something? That way you could run several different devices into a single input as long as only one of them was actually operating. Would it cause signal path problems with feedback or something?

Wiring multiple outputs together even if they're off is a bad idea. If you ever turned more than one device on you'll get odd interactions and interference.

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#336791 - 06/09/2010 21:02 Re: Home theater help: HDMI pass through 5.1 surround to optical? [Re: Dignan]
Taym
carpal tunnel

Registered: 18/06/2001
Posts: 2504
Loc: Roma, Italy
Originally Posted By: Dignan
This is why my next purchase, instead of a new TV, will be a new receiver. That way I'll have all the HDMI coming into the receiver, where all the audio can be handled, and have a single cable to the TV.

This may be probably a more typical EU setup, but cables would be 2 if your digital TV decoder is built into the TV itself, as it usually happens here. In such case, TV audio would either output to the TV speakers (stereo, usually), or you would have to output to the reciever itself to get the 5.1 channels, when available: cable nr 2 from TV to receiver.
Anyway, that would be my ideal setup as well. Onkyo's are nice receivers, and some of the more expensive models even have two HDMI outputs in case you want a TV AND a Projector screen, for example.
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= Taym =
MK2a #040103216 * 100Gb *All/Colors* Radio * 3.0a11 * Hijack = taympeg

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#336792 - 06/09/2010 21:09 Re: Home theater help: HDMI pass through 5.1 surround to optical? [Re: Dignan]
Shonky
pooh-bah

Registered: 12/01/2002
Posts: 2009
Loc: Brisbane, Australia
Originally Posted By: Dignan
Originally Posted By: Shonky
There is one significant advantage to running the devices direct to the TV. Most TVs these days remember settings on a per input basis so you can individually calibrate your sources for best picture quality.

Having a receiver then requires an extra remote so by then you are considering at a universal remote of some description. They really are worth it for WAF though. I can go away for work and my girlfriend doesn't have any issues while I'm gone. The help function fixes things if something gets out of sync.

So do you not have a receiver at all? What is your speaker setup like?

I do have a universal remote, and my wife has zero problems with the home theater because I have the remote set up so that it cannot fail. I LOVE discrete codes!

Oh no. I have a receiver with the full 5.1 speakers. I have a Denon 4308 so reasonably high end. It can do some calibration of inputs but typically TVs can do more and it's better at the TV usually.
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Christian
#40104192 120Gb (no longer in my E36 M3, won't fit the E46 M3)

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#336793 - 06/09/2010 21:51 Re: Home theater help: HDMI pass through 5.1 surround to optical? [Re: Taym]
Dignan
carpal tunnel

Registered: 08/03/2000
Posts: 12338
Loc: Sterling, VA
Originally Posted By: taym
Originally Posted By: Dignan
This is why my next purchase, instead of a new TV, will be a new receiver. That way I'll have all the HDMI coming into the receiver, where all the audio can be handled, and have a single cable to the TV.

This may be probably a more typical EU setup, but cables would be 2 if your digital TV decoder is built into the TV itself, as it usually happens here.

Well, most TVs here do have tuners built in (mine can tune OTA and cable inputs on its own), but I would never ever actually use it. I suspect it will be nearly impossible to ever get me to use something other than my Tivo.

I currently have three cables going to my TV. HDMI, Component, and power. The component is just for the Wii, and if I had a new receiver, I wouldn't need to run that to the TV because it would just convert the component to HDMI.

Ugh, I REALLY want a new receiver...
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Matt

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#336794 - 06/09/2010 22:06 Re: Home theater help: HDMI pass through 5.1 surround to optical? [Re: tanstaafl.]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31597
Loc: Seattle, WA
Quote:
I take it, then, that you can't just use a splitter like on a telephone line when you want to share the phone with a fax or something? That way you could run several different devices into a single input as long as only one of them was actually operating. Would it cause signal path problems with feedback or something?


That's a very interesting question, and one that I asked (in relation to optical inputs) a long time ago here on this very BBS if I recall correctly.

Here's the situation:

The devices in question here are using optical (fiber optic) cables for their digital audio output. This is, as you might expect, a bit of a different animal than an ordinary bit of copper wire might be. The fiber optic cable is a continuous digital data channel that modulates a diode light to deliver high bit rate data. It's more like a network cable than an audio wire. In that situation, you might not expect that a Y-adapter would work any more than you would expect to be able to have a telephone conversation and a fax transmission on the same phone line simultaneously.

But even then, the truth is that, yes, you CAN have a Y-adapter for optical audio cables. In fact, I'm doing that very thing: Two of the optical output devices I'm using are sharing an optical input on my receiver via just such a Y-adapter. They are game consoles, so I wouldn't ever have them both turned on at the same time, so there's no issue with the signals overlapping. That's what makes it work, by the way: In order for the Y-adapter to be possible, only one of the devices can be turned on at a time.

The problem is: Some devices don't share well like that. For example: one of the devices that I'd like to have sharing a Y adapter is my Tivo DVR. This thing leaves its optical input "live" (lit up, red diode light coming out of the little hole) at all times, even if the DVR is placed into standby mode. Because it does this dastardly thing, it cannot share an optical input into my receiver; if I want to use its optical output I can't use a Y-adapter on that device. This is one of the limitations that I'm up against with my TV system's wiring, and one of the things I was hoping the HDMI inputs on the TV would solve for me. Ah well.
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Tony Fabris

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#336797 - 06/09/2010 23:03 Re: Home theater help: HDMI pass through 5.1 surround to optical? [Re: tfabris]
hybrid8
carpal tunnel

Registered: 12/11/2001
Posts: 7738
Loc: Toronto, CANADA
As an aside, I think that the optical (toslink) connector (plug and receptacle) are, by far, the worst interconnects to have ever been designed. Just a dumb-ass idea (the connector, not fiber optics) followed by dumb-ass implementations.
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Bruno
Twisted Melon : Fine Mac OS Software

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#336804 - 07/09/2010 05:43 Re: Home theater help: HDMI pass through 5.1 surround to optical? [Re: Dignan]
Taym
carpal tunnel

Registered: 18/06/2001
Posts: 2504
Loc: Roma, Italy
Originally Posted By: Dignan
Originally Posted By: taym
This may be probably a more typical EU setup, but cables would be 2 if your digital TV decoder is built into the TV itself, as it usually happens here.

Well, most TVs here do have tuners built in (mine can tune OTA and cable inputs on its own), but I would never ever actually use it. I suspect it will be nearly impossible to ever get me to use something other than my Tivo.

Here the market is basically entirely covered by:
1. Digital TV, for which you typically use the built-in receiver. But, many either have older TVs that don't have digital TV receiver or tehy are not capable of the new HD digital TV; in such cases, you would have an external box.
2. Sat, for which you need an external box (which comes also with optional TiVo-style features, but it is not quite the same, unfortunately).

Very little market has TV over IP via few of the major ISPs.

So, if you're not using an external box, it is quite likely your would have to output audio from your TV to your receiver to enjoy decent audio quality, provided it is actually there at the source.

TiVo never made it to Italy, sadly, and I am afraid it is so for most of the EU. Maybe the UK? Everywhere I heard of some tiVo-like services, as I was mentioning, but they don't compare, really, with it.
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= Taym =
MK2a #040103216 * 100Gb *All/Colors* Radio * 3.0a11 * Hijack = taympeg

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#336805 - 07/09/2010 05:51 Re: Home theater help: HDMI pass through 5.1 surround to optical? [Re: Taym]
andy
carpal tunnel

Registered: 10/06/1999
Posts: 5916
Loc: Wivenhoe, Essex, UK
Originally Posted By: taym

TiVo never made it to Italy, sadly, and I am afraid it is so for most of the EU. Maybe the UK?

It was for sale in the UK fairly briefly. It had to compete with the builtin DVR in Sky's proprietary satellite receiver, which although it didn't have the features of TiVo had the benefit of recording the raw feed.

Ironically it was Sky who provided technical support for TiVo in the UK...
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#336824 - 07/09/2010 15:50 Re: Home theater help: HDMI pass through 5.1 surround to optical? [Re: drakino]
wfaulk
carpal tunnel

Registered: 25/12/2000
Posts: 16706
Loc: Raleigh, NC US
I can confirm that my TV only negotiates PCM stereo over HDMI. I was trying to do something very similar recently, except with surround headphones instead of a receiver, and was disappointed to discover that my location presence went away. Took me a while to figure out what it was, but the PS3 confirmed that it wouldn't accept anything but stereo.
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Bitt Faulk

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