Have any of you (successfully) used AppleTV’s “Settings -> Audio and Video -> Wireless Audio Sync” feature with Bluetooth headphones?
I have headphones successfully paired with my AppleTV and otherwise working great, but when I try this feature, no calibration sound comes from the headphones.
Apple TV HD, tvOS 13
My hope is to sync video to BlueTooth headphone audio, not to TV audio. That article seems to suggest that this function can be used for that purpose.
So, how does sending the audio out the TV help for sync’ing video to headphone audio? The timing of TV and headphone audio can be quite different.
I said above the headphones are “otherwise working great,” meaning that the pairing is successful, and I’m getting audio out the headphones. However, that audio is not in sync with the video, thus “otherwise.”
Now all this being said though, although the synchronization isn’t perfect, it’s ... livable. So, if I can’t AV sync, then I guess I can deal with the delay.
The Apple TV is connected to your TV and can then be paired with an external device, such as BT headphones. The process is aiming to correct lag between the TV and all external sources. As such it is using the TV to emit a tone so the iPhone's mic can pick it up and feed it back for analysis and correction. However, synchronization issues can also come from flaws within a particular device or things like interference within the environment. In those cases, at best it may lessen the impact, but it won't be able to solve it entirely and will then require further investigation.
It is normal for the tone to come out of the TV, it is using the phone's mic to measure any lag and correct. If it shows the process completed then it did it's job. However, if it shows that it failed then you will need to move the phone closer and turn on the volume up on the TV.
Set up Wireless Audio Sync with Apple TV - Apple Support
Thanks for replying.
According to https://support.apple.com/en-us/HT210526, this function can be used to sync video with audio over bluetooth headphones. Using the sound from the TV doesn’t help sync video with BlueTooth-headphone audio. Using this function, it does not send sound through the headphones, so it clearly can’t sync with it.
Ah, OK, reading that article again, I see that the purpose of this function is to match TV audio to headphone audio, not headphone audio to video.
That doesn’t make much sense because it seems to be based upon the premise that Bluetooth audio is exactly sync’ed with video and that what may not match is TV audio. I would expect Bluetooth to have small but indefinite (“open-loop”) packet-buffering delays.
Again though, the delay I’m seeing is tolerably small (smaller than when I use the same headphones to watch video on my iPhone), so I conclude:
Thanks for the reply!
Yes, that is the same article I linked above. It also notes that the tone will always come out of the TV. The purpose is to issue that tone and have the phone's mic listen so it can measure the lag and correct it. Having the tone come out of the headphone would be of no use. As I said, if the process showed it completed then it did it's job, and if it failed then you can try again while moving the phone closer and upping the volume on the TV.
If it's working great, as you had indicated, then there is no need to do anything further. However, if you did the sync because you were having issues and it persisted after using the sync then you will need to look into additional factors that are contributing such as something within the headphone itself or the environment (i.e. interference).
AppleTV Audio Sync with Bluetooth Headphones
