# HDMI ARC ?



## SayWhat?

Audio Return Channel, is this something that is only found in TVs from the last year or so? Does it have to be specified on the TV output or is it likely to be there on any HDMI connection?

My Toshiba TV does not have it indicated.

My new Panasonic HT unit does.

I have an optical cable coming, so I'll be covered either way I think.


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## spartanstew

It needs to be specified. It's part of the HDMI 1.4 standards, so it would only be on items that have been released since then (mid-2009).

Additionally, just because a device has HDMI 1.4 (or 1.4a) doesn't mean it will have ARC, as it's an optional part of the standard.

Both your display and the A/V receiver need to be capable of ARC in order to take advantage of it (and really the only use is if your display has apps)


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## SayWhat?

spartanstew said:


> (and really the only use is if your display has apps)


They say it feeds the TV audio back to the amp so you don't need the optical or RCA cables.

No biggie, I should have it covered.

I think I got the TV in Dec '09.


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## spartanstew

SayWhat? said:


> They say it feeds the TV audio back to the amp so you don't need the optical or RCA cables.
> 
> No biggie, I should have it covered.
> 
> I think I got the TV in Dec '09.


What audio do you need to send from the TV? Apps? OTA?


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## SayWhat?

OTA


O'tay? 

(Can't remember who said that, maybe one of Eddie Murphy's characters)


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## spartanstew

SayWhat? said:


> OTA
> 
> O'tay?
> 
> (Can't remember who said that, maybe one of Eddie Murphy's characters)


It was Eddie Murphy playing BuckWheat from the Little Rascals.


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## dmspen

spartanstew said:


> What audio do you need to send from the TV? Apps? OTA?


The newer Panny TVs have Netflix and such built into the TV. I had this same question some time ago. My TV has ARC but my receiver doesn't. I traipsed all the way into the garage for an optical cable, finagled it through my TV stand, connected another HDMI from the TV to the rx, again snaking my arm through the TV stand, and bingo! Viera/Netflix through the receiver!


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## SayWhat?

That brings up another question. Panasonci uses the term Viera while Toshiba uses Regza-Link, but they both reference CEC. Are they the same thing? Will they talk to each other? Or are they separate protocols?


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## spartanstew

SayWhat? said:


> That brings up another question. Panasonci uses the term Viera while Toshiba uses Regza-Link, but they both reference CEC. Are they the same thing? Will they talk to each other? Or are they separate protocols?


Any CEC product will talk to another CEC product regardless of manufacturer.


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## Rich

spartanstew said:


> Any CEC product will talk to another CEC product regardless of manufacturer.


Do you get 5.1 sound thru that or just linear PCM?

Rich


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## spartanstew

rich584 said:


> Do you get 5.1 sound thru that or just linear PCM?
> 
> Rich


CEC has nothing to do with audio.


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## Rich

spartanstew said:


> CEC has nothing to do with audio.


I was talking about the optical out port on the back of the new Net TVs. I have no Net TVs, but all my plasmas have an optical port on the back panel and they only output linear PCM.

Rich


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## Rich

SayWhat? said:


> Audio Return Channel, is this something that is only found in TVs from the last year or so? Does it have to be specified on the TV output or is it likely to be there on any HDMI connection?
> 
> My Toshiba TV does not have it indicated.
> 
> My new Panasonic HT unit does.
> 
> I have an optical cable coming, so I'll be covered either way I think.


All seven of my Panny plasma have the optical out port on the back of the TVs. But they only output linear PCM. I'm trying to find out whether the new Net connected TVs will output 5.1 from those same optical outputs.

Rich


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## RASCAL01

rich584 said:


> I was talking about the optical out port on the back of the new Net TVs. I have no Net TVs, but all my plasmas have an optical port on the back panel and they only output linear PCM.
> 
> Rich


I only use optical and it outputs 5.1, same for my current TV and my old one.


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## spartanstew

rich584 said:


> I was talking about the optical out port on the back of the new Net TVs. I have no Net TVs, but all my plasmas have an optical port on the back panel and they only output linear PCM.
> 
> Rich


If it has ARC, it will be at least DD (but that's an HDMI connection).

With other TV's it's hit and miss. The vast majority of displays that have an optical out are limited to linear PCM, as you've experienced, although there are a few exceptions - as Rascal has experienced.


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## SayWhat?

Userguide on my Toshi says the Optical output can be set for PCM or DD, but it doesn't say 5.1 specifically if there's a difference.


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## spartanstew

Yes, there could be. DD could mean DD2.0


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## CCarncross

rich584 said:


> All seven of my Panny plasma have the optical out port on the back of the TVs. But they only output linear PCM. I'm trying to find out whether the new Net connected TVs will output 5.1 from those same optical outputs.
> 
> Rich


My Panny outputs DD if watching an OTA channel via the built-in tuner in the tv.


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## Rich

CCarncross said:


> My Panny outputs DD if watching an OTA channel via the built-in tuner in the tv.


I don't use OTA. I've tried all my seven Pannys and none of them put out anything but linear PCM. Even the one I just bought a few months ago. Doesn't really matter to me, I have plenty of 5.1 options and three optical switchers, but I've been kinda curious about the Net ready sets. They must all put out 5.1 from the optical port on the back of the set, no?

Rich


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## spartanstew

rich584 said:


> I don't use OTA. I've tried all my seven Pannys and none of them put out anything but linear PCM. Even the one I just bought a few months ago. Doesn't really matter to me, I have plenty of 5.1 options and three optical switchers, but I've been kinda curious about the Net ready sets. They must all put out 5.1 from the optical port on the back of the set, no?
> 
> Rich


Yes, most ouput DD (5.1) with OTA, but linear with everything else.

I would think the sets with Apps should put out 5.1, but knowing manufacturers, it's still probably hit and miss. They just figure people are watching Netflix with the TV speakers.


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## balboadave

spartanstew said:


> Any CEC product will talk to another CEC product regardless of manufacturer.


They may talk, but they don't always listen. Many advanced CEC controls are manufacturer specific, and are only guaranteed to work within the same family. That's why they all have unique names, as a marketing ploy. There's no requirement to be 100% compatible, especially with older models. However, due to customer backlash, later versions are somewhat more compatible with others.



spartanstew said:


> CEC has nothing to do with audio.


CEC needs to be enabled for ARC to work. They share the same wires of the HDMI cable.


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## Rich

balboadave said:


> They may talk, but they don't always listen. Many advanced CEC controls are manufacturer specific, and are only guaranteed to work within the same family. That's why they all have unique names, as a marketing ploy. There's no requirement to be 100% compatible, especially with older models. However, due to customer backlash, later versions are somewhat more compatible with others.
> 
> CEC needs to be enabled for ARC to work. They share the same wires of the HDMI cable.


What, exactly, is CEC?

Rich


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## SayWhat?

> Thanks to an increasingly common technology called Consumer Electronics Control (CEC), your HDTV's remote can manage up to ten devices that are connected via HDMI (such as Blu-ray Disc players or home theater receivers), no special programming needed. So, for example, you can use your remote to turn on your TV, your player, and your receiver at the same time, and adjust the system volume with one button.


http://www.pcworld.com/article/143777/the_secret_feature_on_your_hdtv_hdmi_cec.html



> CEC will simplify hooking components together by using a technique that has been around for some time, known as a handshake. You have been using technology that uses the handshake technique without even knowing it. Computers use the handshake technique all the time to figure out how fast to send / receive information. If you have had the misfortune of answering your voice line when a fax machine calls, that is another (less sophisticated and painful) kind of handshake using DTMF tones. A handshake is just a communication protocol that devices use to inform other devices of its capabilities.


http://www.hdhes.com/converge/hdmi_cec.aspx


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## CCarncross

Here's the skinny on the digital output on most tvs:

If you are using the internal tuner(ATSC), then you will get DD out of the output. If you are connecting an external source like and STB, or a BD player, etc...most will not pass the DD audio out the optical port, but will pass Linear PCM...thats the way its been since the beginning. If you are looking for DD sound from an external source, you must run the audio out of the external source to your sound system...


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## SayWhat?

That could explain something. I'll have:

Dish 5XX >> S-Video & RCA >> TV

HTPC >> HDMI >> TV

DVD HT >> HDMI & Optical >> TV (Unless the ARC works)

Internal TV speakers turned off.

I was hoping to use the TV remote for volume control, but I'm not sure the Optical output is variable. I may have to use the DVD HT remote for volume and set the TV code so I can do channel and source changes. I don't know if the new remote will take the Dish code to control the 5XX box. In the past, any universal or device remote only gave me limited control of the 5XX box. I've been using the Dish remote for most functions, but I'm not sure it will take the Panasonic DVD HT code or how many of the functions it will control.

For that to work, I may need to do: 5XX >> S-video >> TV -and- 5XX >> RCA >> DVD HT 

But then, I can't remember the Dish remote code anyways, so I'll have to find it again.

Babbling, I know. More like thinking in keystrokes actually.


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## Rich

CCarncross said:


> Here's the skinny on the digital output on most tvs:
> 
> If you are using the internal tuner(ATSC), then you will get DD out of the output. If you are connecting an external source like and STB, or a BD player, etc...most will not pass the DD audio out the optical port, but will pass Linear PCM...thats the way its been since the beginning. If you are looking for DD sound from an external source, you must run the audio out of the external source to your sound system...


That's a great explanation, thanx.

Rich


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## SayWhat?

All hooked up and most of it seems to be working. Used the optical cable since I couldn't confirm presence of ARC.

Not sure how to explain what works and what doesn't. I may still have to adjust some settings. There is a difference in volume between sources, so I guess that could be the difference between DD and PCM.

Seems like a lot of the CEC functions are working regarding source switching and audio, but the remotes don't have full control of connected devices. Probably an issue of different manufacturers and CEC versions.

Dish, HTPC, OTA antenna and old VCR are connected to the TV using HDMI or S-Video/RCA where applicable. TV is connected to HTIB with HDMI/Optical.


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