Airport Express Airplay slightly out of sync

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Level 1

13 points

Airport Express Airplay slightly out of sync

I have an Airport Express connected to my stereo. Starting a few weeks ago, I noticed that the AirPlay audio suddenly is slightly out of sync with videos. Please note, I don't mean the 2sec delay that would be observed when the Airplay delay correction isn't working at all: It is working, but it is off target by about a quarter second. This problem came out of nowhere and video was perfectly in sync before.

I determined using VLC, where the delay correction must always be made completely manually for some reason, that the problem must be somewhere in the Airport's processing. The total delay to the audio out is about 2250 ms, and I read somewhere that it should be exactly 2000 ms. So that would explain what's happening. But how can I fix it? It's not in my stereo, as the problem persists when I plug headphones into the Airport.

The problem happens both with my iPhone and my Mac (latest OS everywhere including the Airport express). I tried resetting the Airport Express already to no avail.

Thanks for any pointers

Ben

iPhone SE, iOS 11.1

Posted on Mar 16, 2018 6:18 PM

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Answer 1

Best reply

LaPastenague

Level 9

67,202 points

Apr 12, 2018 1:15 PM in response to tempfile

The co-incidence of your added lag to the latest airport firmware update which has been causing a fair amount of problems for some people (although I don't see a reference to extra delay in airplay.. your setup is a bit unusual).

Let me suggest you downgrade the firmware on the Express.. it is simple to do and will not have any major effects (the increased security is only relevant to KRACK and some other fairly limited security flaws).

Hold down the option key while you click on the airport firmware version. A listing of possible versions will come up.. e.g...

Select whichever .. 7.6.8 or 7.6.7

No luck with that.. let me suggest you trial the airport express stand alone. Still with earlier firmware.

Reset it to factory.. configure it in router mode which is default. Ignore the lack of wan connection. Now just connect your computer or iphone to the express and try your streaming.. do you still have the same added delay issue. If so I would go the next step of eliminating wireless entirely.. using a long ethernet and turn wireless off.. up to you on that one.. I know it would be a bit more effort to manage.

Before you start messing around you can save the current configuration so it is easy peasy at the end if you make no progress to restore the express.

For export configuration to be active you need the setup open.

Then to restore you simply Import the Configuration file.

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Answer 2

Tesserax

Level 10

148,339 points

Mar 18, 2018 11:07 AM in response to tempfile

Sorry, those tips didn't help. Unfortunately, without doing a full spectrum analysis, it would be difficult, whether or not, any type of Wi-Fi interference could be an issue. Running Ethernet certainly would rule that out.

However, placement of your Express may be optimized to see if that can help. Please take a look at the following AirPort User Tip. Although it was written about optimal base station placement for extending a Wi-Fi network, it still applies in this situation. In this case you want to find the location where the Express is in an "excellent" SNR range of your wireless gateway.

AirPort - Optimal Base Station Placement

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Answer 3

Tesserax

Level 10

148,339 points

Mar 18, 2018 10:26 AM in response to tempfile

Thanks for the additional information.

If the Express is not in the same room as your main wireless gateway device, I suggest the following:

Assign it a static private IP address instead of it getting an IP address from the gateway via DHCP.
Connect it to the 2.4 GHz radio of the gateway.

FWIW. When streaming the stream goes from the host device to the gateway by wireless. It then is sent to the Express from the gateway, also via a wireless connection. Depending on where the host device is situated when streaming this could have an effect on the stream quality.

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Answer 4

Tesserax

Level 10

148,339 points

Mar 17, 2018 10:10 AM in response to tempfile

If you could please provide some additional information on your current network hardware and configuration that you are using for streaming, it would help us to figure out why your system is experiencing additional delays.

Is the AirPort Express the only router in your current network configuration? If it is, what exact model is it and what is the make & model of the Internet modem that it is connected directly to by Ethernet? If it is not, please provide the make(s) & model(s) of all the other networking hardware being used ... and how you have each of them configured.

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Answer 5

tempfile Author

Level 1

13 points

Mar 18, 2018 8:12 AM in response to Tesserax

Hi there, thanks for replying.

The Express is not the only router. I use it only as an AirPlay receiver now because the main router is an all-in-one from our DSL provider. (However, this configuration worked fine until a while ago, unless I'm confused.)

The main router is a Huawei made custom model from our network provider (German Telekom Speedport Smart). It's a POTS/DSL/Router/Wifi all-in-one connected directly to the main landline. No wired network devices connected, wireless only, the thing knows printer and storage sharing but nothing is connected.

Configuration:

WiFi: 2.4G (b/g/n) and 5G (ac), two separate network names, auto channels, WPA2. (It makes no difference which one the Airport connects to).

DHCP, IPv4 only. (Pinging the AirPort express from my Mac yields <3ms latency)

The Airport Express is set to "Connect to a wireless network" via DHCP. IPv6 is set to Automatic. There's no Airplay password set. No devices are connected except the audio out. As you know there's not many more settings I can make.

Does this ring any bells? I'm really at a loss esp. looking at the fast ping to the Express.

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Answer 6

tempfile Author

Level 1

13 points

Mar 18, 2018 10:57 AM in response to Tesserax

Thanks for the tips, no change unfortunately :-( Next, I'll see if I can get hold of a very long network cable and use it to wire up the Express to the main router. I really don't understand how this suddenly appeared. In my old large flat with WiFi impenetrable walls, it was connected to the main router through a shoddy contraption of a wireless repeaters and Powerline adapters, while still keeping A/V perfectly in sync. I was totally impressed how Apple pulled that off!

Ed. is there maybe some sort of debug mode to Airplay, or could I write up a quick script/app in order to get more information out of the framework?

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Answer 7

tempfile Author

Level 1

13 points

Mar 18, 2018 11:07 AM in response to Tesserax

Yeah, of course these issues are insanely complex with all the possible setups involved. I'll look into the guide. Thanks for taking your time here, I'll update this if I find out something useful! :-)

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Answer 8

tempfile Author

Level 1

13 points

Apr 12, 2018 1:17 PM in response to LaPastenague

Hi there, thanks for the tip! I never thought that Apple would allow firmware downgrades! (I was only able to go back one version successfully, not two).

Unfortunately no change, the problem is the same with the older firmware. It also persists in all configurations, wired, with its own Wifi network, as a standalone airplay server… so frustrating! It worked perfectly until a few weeks ago. Maybe it is a hardware problem after all.

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Answer 9

Apr 12, 2018 2:46 PM in response to tempfile

It seems you are stuck. I am not sure where the extra latency has come from.

In the end we troubleshoot these problems step by step.. you have eliminated as much as you can without introducing new hardware.

My recommendation is go with the hardware problem on the express (we did not yet discover how old it is). Buy a new one and see if that fixes the problem. If so you won. If not return it during the 14 day return period as it is not the issue.

I have to say the express is very reliable. Unless it is gen1 or very old gen2 I don't think hardware is very likely.

You will need to figure out some other method to connect your stereo to the video or use different streaming software that allows more flexible timings. It is frustrating when the system has worked fine for so long.

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Answer 10

Rudegar

Level 10

170,658 points

Mar 17, 2018 3:06 AM in response to tempfile

got 2 and 1 appletv and airplay always been out of sync for me suppose wifi interference and network setup latency are the cause

the upcoming airplay 2 is claimed to solve it though we'll see

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Airport Express Airplay slightly out of sync

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