Audio via HDMI question

[Haslar]

Hi,

I'm in the process of modifying my audio & video setup.
I want to use my LG C1 TV as a monitor only. It would be hung on the wall, with no visible cables (all cables would go in the wall, and I want to keep them as few as possible).
All audio would be played by my NAD C3050.
The NAD and the TV are both e-ARC compatible, so I'd like to take advantage of that.

I have the following video sources:
- LG C1 TV
- TV Box
- Panasonic Blueray
- Sony Playstation

I need to have only 1 HDMI cable to go to the TV. So I guess I need some kind of active HDMI switch device, that can handle the various sources, and send the signal via just 1 cable to the TV.
It also needs to handle the e-ARC system, and the connection towards the NAD.
I am on the right track when I consider a device such as the Feintech AX340? And if I purchased it, I guess I'd connect the NAD to the "Soundbar e-ARC" HDMI plug.
I am right, or I am missing something?
I guess I could also imagine using the Toslink out connexion from the TV to go to the NAD for audio, but have no idea if that would be a better option than the e-ARC HDMI option.

Many thanks in advance!

 

[Plcamp]

From the very limited investigations I have done, it seems that you can’t trust the TV digital out to pass through an unaltered pcm audio signal, but with ARC you can.

So I would stick with ARC.

 

[Redacted]

Seems complicated to me.
So, your TV has several HDMI inputs, but you want to use only one of them and switch one of several sources into it (so only one cable for the input)...
If you want to feed a stereo with an ARC input, you'll normally let the TV to do the conversion to PCM stereo from whatever input is going into it - the issue is "which device is doing the conversion to stereo PCM?"

In any case, if you let the TV do the conversion, you'd need a second HDMI cable to connect to you the ARC input on a capable stereo - the TV, if set to use ARC PCM, will then not make any audio through its own speakers, and work as monitor...
I'm not sure what the Feintech AX340 actually does besides switching, but if you can live with one cable in to the TV (switched source) and one cable out (ARC to stereo), a much cheaper switch might be used to select between sources:

Amazon.co.uk : B09Y14JSFH

 

[Haslar]

Thanks @Plcamp and @Redacted for your replies. Things are a lot clearer for me now.

I guess I need to decide whether I need an audio extracting capability, or if I let the TV do the job.
If I let the TV do the job, then I need a second HDMI cable fro the TV out to the NAD C3050 indeed.
If the HDMI switch device does the extraction, then I can connect it to the NAD via HDMI, Toslink or coaxial. But I'm not sure that I see any advantage to this option.

I suppose I can live with a couple of HDMI cables plugged in the TV, one bringing the video, the other sending the audio.

I need to make sure I select a device that is 4k 120 Hz HDMI 2.1 compatible, though.

 

[Redacted]

For the ARC cable from the TV to whatever receives the PCM stereo signal, it can be quite thin, and frankly, cheap. A low-spec Amazon Basics is more than enough. Bear in mind it it is only carrying a relatively low speed PCM stereo audio signal - wet string could almost do it.

As a side note on HDMI cables being used for ARC, on other forums I have told a few people to ditch their top of the range, ultra-spec cables that did not work for a basic cable, which as if by magic, worked fine. It's to do with using pins in the cables of the higher spec HDMI cables that are not connected or not used in the lower spec cables or kit. They should be backwards compatible but it depends on the TV or the audio kit as to how it treats certain pins that the kit does not expect to be in use (my guess).

 

[Haslar]

For the ARC cable from the TV to whatever receives the PCM stereo signal, it can be quite thin, and frankly, cheap. A low-spec Amazon Basics is more than enough. Bear in mind it it is only carrying a relatively low speed PCM stereo audio signal - wet string could almost do it.

As a side note on HDMI cables being used for ARC, on other forums I have told a few people to ditch their top of the range, ultra-spec cables that did not work for a basic cable, which as if by magic, worked fine. It's to do with using pins in the cables of the higher spec HDMI cables that are not connected or not used in the lower spec cables or kit. They should be backwards compatible but it depends on the TV or the audio kit as to how it treats certain pins that the kit does not expect to be in use (my guess).

Thanks for the insight!

I was thinking about ordering the following, from Amazon:

FeinTech VSW14100 Switch HDMI 4K 120Hz​

2xKabelDirekt – Câble HDMI 2.1 10K & 8K – 3m​

These HDMI cables are not expensive (17 euros each) and seem well-made.

 

[Redacted]

Looks a good switch to me. I bet the "auto" function was welcome.
KabelDirekt are good - I usually buy and recommend their speaker cable.

 

[Tre2023]

I would connect the three devices directly to the C1 and use a single HDMI cable out of its eARC port to the NAD C3050’s eARC port. I’ve done as much in the past when connecting various devices to my C1.

Since the NAD C3050 supports only two channel PCM, an optical connection would also suffice and I’ve used it on occasion myself with the C1. Though, this would remove the HDMI-CEC capability present in the C1 and NAD C3050 but the C1 also features universal remote control functionality that works with devices connected over optical with varying degrees of success.

Whatever the chosen setup, make sure two channel PCM is set for output in every source device, especially the Playstation, and also set for output in the C1 as the NAD C3050 can only accept a two channel PCM signal over eARC.

The C1 can re encode signals for output. When doing so, lip sync issues can and usually do arise which is why outputting two channel PCM at the source is important here.

Concerning audio using HDMI vs optical, there will be no audible difference in sound as the TV will output a 48/24 two channel PCM signal over both of them when set to output PCM from sources sending two channel PCM to the C1.

An additional benefit to connecting devices directly to the TV is use of the universal remote control function. You can potentially need only the magic remote to control everything with a combination of supported devices. Things can get complicated when going through a switch but may be necessary if wanting to reduce the number of cables going to the TV.