That delay would be in the TV set, and not the Sonos, which plays whatever it is handed, as quickly as possible. I’d double check with the TV manufacturer, and see if there’s a software update for the TV. 

The TV (LG OLED Series is running latest firmware.

As this is the first soundbar I have connected via ARC (previously Playbar via TOSLINK) I’m not sure if this is normal for a delay in the Arc (or any other soundbar connected via ARC) to turn on.

Reading up on HDMI/HDCP it seems there some handshaking between connected devices, that is not present with TOSLINK, and possibly requirements for low power consumption of devices that causes a delay when turning on from sleep?

My current situation is:

I press power on on the TV remote.

2 Seconds later I see a picture on the TV.

5 seconds after seeing picture (or total 7 seconds after pressing power) the LED flashes green on Arc and immediately after I hear sound from Arc.

Note: I checked LED status here https://support.sonos.com/s/article/226?language=en_US and flash Green suggests setup or possibly Mute?

Previously (with Playbar):

I press power on the TV remote.

2 seconds later I see picture and hear sound from Playbar.

So my question is, is this typical, ie flash Green LED after 5 seconds and then hear sound from Arc?

I have seen this delay as well when I power on my Sony Bravia Oled, there is a delay until green light goes off in my case, since the stable green light is on when everything else is powered down

you might check the “Group Audio Delay” setting. it can range from 75ms to 2000ms so if it’s up at the high end you can cut nearly 2s out of the delay.

>settings>(room with Arc)>(scroll down to Home Theater section)Group Audio Delay]

@recruiter89 How long is the delay after you see picture on your Sony until you hear sound from Arc?

I don’t see the Arc LED on, just flash green for half a second before I hear sound, 5 seconds after I see picture. Green suggests ‘mute’, assuming same colour LED colour scheme is same as here  https://support.sonos.com/s/article/226?language=en_US.

The issue I’m seeing is initial delay after seeing TV picture when TV is powered on, until I hear sound from Arc. The above is to add extra buffer, if there are network issues. In any case mine is set to default 75ms.

probably 20 seconds, maybe 30 or until I hit volume up on the remote button...plus I get steady green MUTE when Arc is in off mode and until it recognizes sounds from TV

I just tried to Vol+ trick, pressed every second after I see picture, but no change, still wait 5 secs before I hear sound. I don’t see steady/solid green light at all. Just a green flash, just before I hear sound. And a white flash when I press Vol +/-

Previously with Playbay via optical I would hear sound as soon as I saw picture. I understand HDMI-ARC is a little more complex, as there is some possible HDCP handshaking going on (even during social distancing  ), so could understand a delay of a second or two, but is 5 seconds normal?

I'm having the same issue with a Samsung QE55Q85R, about 10+ seconds after picture appears before Arc LED shows green and then sound arrives. What to do? 

Talk to Samsung about the delay in the ARC handshake?

Update your software on the TV? 

This isn’t a Sonos issue, it’s an issue in the TV not sending a signal quickly enough when it starts up. 

I fixed this by changing my hdmi cable. Presumably my previous cable was not speedy enough. 

I have the very same issue with my LG OLED55E7N tv.

When the Sonos ARC is connected via HDMI I have got the delay, when connected using optical I don’t.

I switched HDMI cables (the one that was included by Sonos with a premium AudioQuest Forest)  without any succes.

I tried changing different settings on the tv without any succes.

I contacted Sonos but they couldn’t detect any issue in the diagnostics. Also they weren’t at all aware of people having this isse, so threated me as a complete isolated case

I contacted LG about the issue but they simply told it was due to a compatibility issue they couldn’t help me with (in general if it’s not LG equipment we can’t assist).

So, I guess I will have to live with it?  It’s not that the Sonos ARC doesn’t work, but as an upgrade to my previous system (Bose Lifestyle 135 which lacked support for different things and which didn’t have this issue) I’d rather didn’t have this issue of course.

I keep on following this hoping some sort of solution would come up...

Just wanted to say I’m having the same problem, using a Sonos Beam, upgraded my TV to one which has ARC, and now I get a short period with no audio when I turn the TV on or if there’s been no audio for a few mins (eg I’ve paused something, or left Netflix on a menu for a few minutes). This didn’t seem to happen with my old TV which was connected via the optical adapter.

I don’t mind it so much when I first turn the TV on, but when I’m partway through watching something, it’s annoying.

If it’s something to do with standby/low power mode when no signal is received for a few minutes, can I change that timeout or disable standby as a workaround? Or should I just go back to the optical adapter?

You won’t get Dolby Atmos from optical so it make no sense to do so just because of this...

With my Sony TV, about 2 seconds after the TV is turned on, the picture will flash black for one second, after which the Arc starts to work (and the TV says that the audio system is connected). Overall, it’s a five second delay. It’s a little annoying. I suspect it’s related to EDID handshakes between the TV and Arc.