Janky A/V setups

May 23, 2021 12:39 PM

I'm trying to route around my ancient receiver's lack of HDCP 2.2, but ARC doesn't seem to be working...

As mentioned in a previous Ask, I've just gotten a 48" LG CX. Unfortunately, while my Yamaha RX-V677 allegedly passes through 4K, it does not support HDCP 2.2, meaning no 4K content for anything that passes through it. My blu-ray player has two HDMI ports, which allows me to run the video directly to the TV and the sound to the receiver. But my Apple TV, unsurprisingly, does not.

In theory, I should be able to run the Apple TV output to the TV and send the sound downstream to the receiver via ARC. I have the HDMI cable (which is high speed, though not very latest) running between the TV's ARC HDMI port (HDMI 2) and the receiver's HDMI Out port. I have the TV set to HDMI ARC; I have the receiver set to HDMI Control. The "TV scene" on the receiver is supposed to receive ARC input, but I've also tried switching through every input. No sound.

What am I overlooking?

posted by praemunire to Technology (12 answers total)

On my older denon receiver and new 4k sony, the only way I can get audio to flow via arc is to have it output pcm instead of any of the surround sound formats. Which is disappointing, but works.

The other standard things apply, your lg may have a specific HDMI port for arc, and there's probably a screen full of arc settings in your tvs menu to tweak.

And a similar set of settings on your receiver to look into. Sometimes hdmi-cec has to be on for arc to work on some receivers.
posted by TheAdamist at 1:03 PM on May 23, 2021

Response by poster: On my older denon receiver and new 4k sony, the only way I can get audio to flow via arc is to have it output pcm instead of any of the surround sound formats.

Just tried setting the HDMI input for that TV port to PCM (doesn't seem to be a way to directly change the output). No joy.

your lg may have a specific HDMI port for arc

Yes. It's HDMI 2. That's where the cable is plugged in.

and there's probably a screen full of arc settings in your tvs menu to tweak

The TV has an audio out: HDMI ARC setting which also appears to turn the "Simplisafe" (their name for CEC, I think) settings on. Note that the power command to the TV also turns on/off the receiver, so there is some communication going on between the two.

a similar set of settings on your receiver to look into

Yes, you need to have HDMI Control and ARC turned on, and I do.
posted by praemunire at 1:15 PM on May 23, 2021

I'd expect the receiver's port labeled 'HDMI out' to send stuff out. Sounds like you want to send from the tv to the receiver, that would be an 'in' port from the receiver's perspective. I don't use those ports or HDMI so I may be off base, but if it were a classical analog a/v signal, you'd send to an input on the receiver, not an output.
posted by SaltySalticid at 1:53 PM on May 23, 2021

Salty, HDMI arc is audio return channel, on the receiver video out it allows the tv to send audio back to the tv. But like much of hdmi it's complicated and when equipment is of different vintages they don't work great together unfortunately.

Praemunire, I just thought of one other thing to check, make sure earc is disabled, it's newer and does things differently than arc. You may also have to set audio to external or something, lg should have a manual that walks through configuring arc. Also check your tv HDMI port settings, my tv has a few relevant settings, I'd disable any of the more enhanced modes that might be available.
posted by TheAdamist at 2:19 PM on May 23, 2021 [1 favorite]

Response by poster: Yeah, Salty, it seems quite counterintuitive, but ARC works (when it works!) over the HDMI OUT port.

I've got eARC off. LG has an audio setting specifically for ARC, which is turned on. I've got the TV sending PCM source now. Still nothing.

I had ordered some extra new HDMI cables anyway that arrived today, and just tried swapping out the older-though-should-still-be-capable-of-audio-return cable with a brand new one. No improvement.

I've got a digital optical cable now, and I guess I can fall back to that, but my understanding is that that is worse quality. I wonder if I could use an HDMI splitter to mimic the effect of having two HDMI out ports on my bluray player, sending the signal to the TV and to the receiver?
posted by praemunire at 4:59 PM on May 23, 2021

I think you're going to need something like this:

https://www.bhphotovideo.com/c/product/1416215-REG/kanex_k172_1026_bk7i_hdmi_a_v_digital_adapter.html/overview

This I believe will give your Apple TV similar outputs to your blu ray player; one video output to go to your TV and a separate audio only output to go to your receiver.

AFAIK, the entire point of HDCP is to make the system unusable if any of the components are not HDCP 2.2 compliant.

ON preview, seems like you just figured this out yourself.
posted by Larry David Syndrome at 5:04 PM on May 23, 2021

On second thought, what I linked to doesn't seem like it will offer much advantage over just using the optical out of your Apple TV and doesn't seem to offer an HDMI audio output.
posted by Larry David Syndrome at 5:08 PM on May 23, 2021

Response by poster: If someone else doesn't come along with a brilliant ARC solution, I think something like this splitter would do the trick (at least one review reports successfully using it for this purpose). I have a Harmony remote so I don't really need the control functions of ARC/CEC.
posted by praemunire at 5:11 PM on May 23, 2021

Response by poster: I did one last round of checks and then gave up and ordered the splitter, resigned to having to use the TV speakers til it arrived. Turned the TV back on a few hours later...suddenly the TV recognizes the receiver (its name appeared in the HDMI ARC square in the dashboard) and it works! Weird. No changes. Guess I'll have to see whether this happens consistently or whether I should use the splitter anyway.
posted by praemunire at 9:56 PM on May 23, 2021 [1 favorite]

Best answer: sometimes the hdcp handshake is wonky and either needs time or a specific startup sequence in order for all the components to recognise each other. maybe that's what happened here.
posted by alchemist at 12:48 AM on May 24, 2021 [2 favorites]

Weird. No changes. Guess I'll have to see whether this happens consistently or whether I should use the splitter anyway.

Good luck. This kind of crap is why I don't recommend LG tvs. If you have my luck it'll work for about 1 year, and then be out of commission the rest of the time you own the TV, just pissing you off as you occasionally try to get it working again.
posted by The_Vegetables at 8:16 AM on May 24, 2021

Response by poster: To be fair, it's a cheap receiver from 2015. I'm not sure LG is to blame.
posted by praemunire at 9:24 AM on May 24, 2021