A little while ago, I set up ARC between a Marantz SR1605 and a Sony X850B. It works flawlessly, and intuitively. Fully automatic, and nothing I would want to change.

So, today, I expected setting up ARC between a Marantz SR5009 and a LG 55LH5750 would go similarly as well... nope! With all the settings correct, nothing works.

The only response I can get is in the LG's sound menu, toggling between internal speaker and HDMI out, switches the Marantz to the TV Audio input - but there's no sound, and it never leaves that input (like the Sony does when you're done). And in the SimpleLink menu, I can tell it to use HT speakers, and it says it's connecting, but again no sound and no automatic switching.

How can one company get it right... and another be so wrong?

Anyways, back to optical...

Your post epitomizes why most of us in this industry do not use ARC.

Oh, agreed - but it clearly doesn't have to be this way. Between the Sony and the Marantz, it works like a dream. That should be the norm, not the exception.

just like HDMI...it works every time!

Sony/Integra combo actually works quite well also.

LG in particular seems to have their own idea on how ARC and CEC should work... and it doesnt seem to play nice with anyone.

Well, optical works fine, although isn't as convenient from a wiring or [potential] operation standpoint. Kind of some stupid operational quirks too - like, if you're in an app, you can't send a discrete input - it flashes "function not available". First, you have to EXIT the app. Sigh.

Knew there was a reason I stick to Sony... but this was a rewards points (Air Miles) freebie, since a huge chunk of mine are expiring this year.

This is also why we usually insist on a streaming box instead of using TV apps.
1) They are cheap.
2) Work 10x better.
3) Far better interface and apps.
4) Can be used the same on a new display.
5) Can be slapped onto the back of even a small TV if need be.

Panasonic displays, tested two models. One plasma and other LCD. To a Pioneer Elite AVR works great. Gave me the ability to not allow either to turn each other on/select input or off for that matter. Just the ARC working.

KOT

It's the LG TV. I have done ARC with Sony Tv's using Sony, Intetgra, and Marantz no problem. All were cases where the client was cutting the cord, and tehy needed a way to get the TV sound back to the AVR.

On the lg tv, you have to turn on "simple link" and something else if I remember right. I stay away from ARC if I can

Yeah, that was part of my initial config (without that, there's no option to switch between TV/HT speakers). Between that and the SLIGHT triggering of the TV Audio input on the amp, there's something getting through - but not enough to actually work.

I know they tweaked CEC in HDMI 2.0 so that supposedly it actually works and every manufacturer had to adhere to the standards to get HDMI license/certification. Not sure they did anything with ARC along the same lines, but it is ridiculous that they implemented a very useful feature, but then the manufacturers ruined it for everyone by only implementing it 50%. Some receivers, as alluded to above, give you more control over what it will and will not do when using CEC. It is nice to find a combo that works. I did it with a Panasonic plasma and a Denon receiver about 6 years ago and it worked brilliantly.

We have been pulling Toslink cables to all our Sony 4k installs so we can give clients at least a taste of 4k material without having to put in a Roku 4. I have not really attempted setting up ARC with our normal Yamaha AVRs in a bit. I guess I better try again to see if they made it any better. Not holding my breath though.

Doesn't ARC only give you two-channel sound, meaning any surround you get is basically ProLogic?

If you're using the tuner in the TV, yeah, you're stuck, but why in the world would you use TV sound for anything else? I guess I haven't HAD to do so yet.

ARC has a 1.5mbit bandwidth and the exact same capabilities as a normal optical/coaxial digital connection - meaning PCM 2.0 stereo, Dolby Digital 5.1, and if the TV supports it, DTS 5.1.

Aside from the tuner you have all the various built-in apps such as Netflix.