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HDMI Audio Return Channel Conundrum

Scott Wilkinson  |  Mar 2, 2012

I have a Panasonic TC-P50GT30 plasma TV and Pioneer VSX-1121 A/V receiver, both of which support HDMI version 1.4 with Audio Return Channel (ARC). The AVR's HDMI output is connected to the TV's HDMI input 1, which is the only input with ARC capability. I also have a PS3 connected to one of the TV's other HDMI inputs. When I play a Blu-ray disc on the PS3 and listen to the audio through my AVR, all I see on the AVR display is Stereo. However if I connect the PS3 to the AVR directly, I see Dolby Digital (or whatever the audio format is) on the AVR display. Does the Panasonic plasma not pass the advanced Blu-ray audio formats, such as Dolby Digital Plus, Dolby TrueHD, and DTS-HD, to my AVR via HDMI ARC?

Dan

First of all, your connection scheme seems pretty whacky to me. Why would you connect the PS3 to the TV rather than the AVR to begin with?

For those who might not be familiar with Audio Return Channel, this feature of HDMI 1.4 allows compatible devices to send audio from an HDMI input to a compatible HDMI output—in other words, in the opposite direction of the normal signal flow. It's used mainly with an ARC-compatible TV and AVR connected in the normal manner—that is, the AVR's HDMI output is connected to the TV's ARC HDMI input. (As with the GT30, not all HDMI inputs on a given TV are ARC-compatible.) When you watch the TV's internal tuner or online streaming apps, the audio is sent back to the AVR along the same cable that usually carries audio and video from the AVR to the TV. This eliminates the need for a separate TosLink or coax digital-audio cable from the TV to the AVR when the audio is generated by the TV itself, as shown in the diagrams above.

ARC can convey Dolby Digital, DTS, and PCM, but none of the advanced codecs, such as Dolby Digital Plus, Dolby TrueHD, or DTS-HD. After all, none of these codecs are used with over-the-air, cable, or streaming content.

I'm kinda surprised that your connection scheme works at all—ARC is not intended to take audio coming into one HDMI input and send it out from another input. I would definitely connect the PS3 to one of the HDMI inputs on your AVR instead of the TV, which will simplify the system and let you hear all the advanced codecs in their full glory. If you use the TV's internal tuner or online apps, keep the AVR's HDMI output to the TV's ARC HDMI input, and you'll hear the audio from the TV without having to connect a separate audio cable from the TV back to the AVR.

If you have an A/V question, please send it to askhometheater@gmail.com.

COMMENTS
unisenmedia's picture
Submitted by unisenmedia on March 3, 2012 - 6:42am

Although ARC has its purpose it was not intended for those using a surround sound system. The TC-P50GT30 does have a Digital Audio out and if one was determined to have the HDMI's connected directly to the TV then that is what needs to be used to audio out to the AV receiver. I get a lot of clients that think that hooking the HDMI's directly to the TV is better than going through the AV receiver and it is not true with a GOOD AV receiver. www.unisenmedia.com

JoeBlogg1983's picture
Submitted by JoeBlogg1983 on March 4, 2012 - 12:30pm

Hi Scott:

I find the ARC method of connection very unintuitive. I prefer the information in my system to flow as follows:

Source-> AV Receiver -> LCD Screen and Speakers

Here's my question: Is there any models of rabbit ears / antenna that will allow me to have the setup I described (e.g. box with rabbit ears and an HDMI output or component output)?

Scott Wilkinson's picture
Submitted by Scott Wilkinson on March 4, 2012 - 3:51pm
To do what you want, you need an external over-the-air (OTA) tuner with an antenna input and HDMI output. My favorite such device is the TiVo DVR, but that incurs a monthly subscription fee for the program guide. Alternatively, the Channel Master TV CM-7400 offers a subscription-free OTA tuner and DVR as well as streaming from various online sources. I have yet to find an indoor antenna that works very well; rooftop antennas work much better.
JoeBlogg1983's picture
Submitted by JoeBlogg1983 on March 5, 2012 - 8:19am

Hi Scott, thanks for your reply! Unfortunately, I live in a condominium building that does not allow me to place an antenna in the balcony...I will do some more research into the Channel Master.

I am also wondering: are there any cheaper models without the digital recording functionality? (i.e. plain vanilla OTA input w HDMI output)

Thanks!

moonchild's picture
Submitted by moonchild on March 5, 2012 - 9:38am

Scott, VUDU passes Dolby Digital Plus and Netflix will be shortly. HDMI 1.4 allows for these HD codecs to pass through to your avr or processor from streaming providers.

allessior's picture
Submitted by allessior on January 18, 2013 - 4:36pm

I have a Sharp 70" with Aquos Link with support of ARC via HDMI1. I connect via HDMI to a NAD757V2 which supports ARC.

I configure the 757 for Auto ARC as I do for the Sharp.

Bottom line: the 757 displays "HDMI ARC" on its' display but NO SOUND.

I even tried setting the 757 Control bits to Source Setup and configured various ports for ARC, but no dice.

Any suggestions? I really don't want to run an optical cable at this point because the TV is in the Lanai and the 757 is in the equipment cabinet in the family room. New cables need to go through the attic then snaked back down to the 757. It is a pain. The existing HDMI cable is about 15ft.

So can somebody help me?!!!!

allessior's picture
Submitted by allessior on January 25, 2013 - 12:38pm

Well, just got off the phone with Aquos Support.

They were adament that the original intent of ARC was to redirect sound from other TV HDMI input ports to the HDMI input port on the TV, so you could send sound from other TV sources to your receiver without using an optical cable. But the other TV sources had to be connected to the other TV HDMI ports.

I did not see this in the HDMI 1.4 spec. The spec basically says that ARC allows you to send Audio from the TV to the AVR without running an optical cable. It does not specify that the only way to use it would be to have other HDMI inputs on your TV redirect sound from the connected sources on those ports. I mean, how stupid, that would defeat the purpose of avoiding other cables because then you would have to run all component outputs TO THE TV HDMI inputs....curazzy.

Was this guy at Sharp just playing pretend and acting smart or is he right?

That means you cannot avoid running the optical cable if you want to send audio that originates from the TV itself, such as from the on-board tuner or the on-board apps, such as Netflx.

Who knows the truth?

allessior's picture
Submitted by allessior on January 25, 2013 - 7:26pm

The HDMI 1.4 standard does NOT require that audio originate on one of the HDTV's HDMI ports. This contradicts what Sharp tech support told me. In fact, I have an LG HDTV which sends audio from its on-board apps to the AVR via ARC. Sharp really should think about upgrading its' tech support staff.

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