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Audio delay on various TV inputs through Sonos Amp over HDMI

  • 6 June 2022
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Hi there,

I have a Sonos Amp connected to my Vizio TV television for Audio. I consistently seem be seeing a lag in Audio that results in lip sync issues where audio lags the video. My understanding is that the features on the Sonos and on my TV are designed to address issues where the audio is ahead of the video rather than the opposite. Therefore, neither is helpful.

I have noticed this for various inputs including the built-in chromecast on the TV, but also just TV over the air direct from the antenna.

Set-up includes:

  • HDMI connection from TV to Amp believe through that specialized type of HDMI port. ARC I think?
  • Low latency setting in Sonos (75ms or whatever the latest setting is there)
  • Various digital output settings on TV including Bitstream, Auto, and Dolby. All seem to have basically the same result.
  • Two Sonos Ones set-up as rear speakers 

Is this just expected given the way that Sonos shares audio with devices wireless even if I’m not actually listening to those other devices? Anything else I can configure in Sonos or on my TV to improve this?

 

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Best answer by buzz 8 June 2022, 22:46

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Hi.  There are loads of existing threads on this topic.  Until time travel is possible Sonos will be unable to play audio before it receives it.  This is caused by the TV sending out the audio after the picture.  Sonos has no control over when the Tv displays the video and can only possibly delay audio, not accelerate it.

The only satisfactory solution is to bypass the TV for audio using a device such ss an HDFury Arcana.  (I think that would work with the Amp, although I have only used it with an Arc.)

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@Boo Radley Have you tried connecting the Amp to the TV via optical using the HDMI to optical adapter?

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Hi.  There are loads of existing threads on this topic. 

Can you link me to any particular one about Sonos Amp and TV audio delay? I’ve seen it discussed for Soundbar and Connect but not just the Amp and wasn’t sure if it was unique in any way.

Until time travel is possible Sonos will be unable to play audio before it receives it.  This is caused by the TV sending out the audio after the picture.  Sonos has no control over when the Tv displays the video and can only possibly delay audio, not accelerate it.

I totally understand this. Though this problem does seem somewhat specific to Sonos. My suspicion is that is has to do with the fact that Sonos must impose a bit of a delay in order to ensure audio is synced wirelessly with my back speakers, for example.


What I’m asking is if there are any techniques for lowering the latency/delay imposed or even telling the TV that there is an audio delay and to slow down the picture (not the audio) if that even makes sense.

The only satisfactory solution is to bypass the TV for audio using a device such ss an HDFury Arcana.  (I think that would work with the Amp, although I have only used it with an Arc.)

When you say “bypass the TV for audio” what does this mean if it’s the TV itself generating the audio? My TV has a built-in chromecast device. I’ve tried to do everything I can to effectively disable the TV’s audio and pass it to Amp in the purest, least processed form.

@Boo Radley Have you tried connecting the Amp to the TV via optical using the HDMI to optical adapter?

 

I have not. Is people’s experience that optical has better performance for audio out than HDMI?

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What’s also odd about this is that it seems somewhat input specific. For example, I notice this on TV over the air but not as much when watching Netflix through the TV’s built-in Chromecast (aka SmartCast). Also some apps that I chromecast for my phone seem worse than others (e.g. live sports on ESPN). Is it possible the TV is handling audio in different ways for these things or that the audio itself is of a different format that is exacerbating the problem?

The film industry dealt with lip sync in the 1940’s. I’m not convinced that TV stations even care. While standing in a TV master control room I remarked that there were some lip sync issues. The staff just glared at me as if to say: “you don’t get it”. In my experience lip sync can vary from channel to channel and program to program. Film channels seem to be the best.

My observation is that cable boxes tend to be the worst in terms of lip sync. I don’t know if this is due to the TV stations not caring or the cable company and their box designers not caring. Many TV’s and A/V receivers will compensate for their own audio and video delays such that there will not be any accumulated relative delays as the video signal passes through. Curiously, this is not always the case for purely audio signals passing through an A/V receiver. The receiver will probably use digital processing for surround effects and the tone control/equalizer. There is some delay inherent in this processing and this can result in some sync issues with pure audio signals. Typically, there is a “direct” setting that will bypass this processing and pass through simple stereo.

When SONOS players are “Grouped” there is a 75ms latency. The latency is reduced to about 30ms for the TV connected to PLAYBAR/BEAM/ARC/RAY/PLAYBASE/AMP.

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Thanks buzz.

 

Curiously, this is not always the case for purely audio signals passing through an A/V receiver. The receiver will probably use digital processing for surround effects and the tone control/equalizer. There is some delay inherent in this processing and this can result in some sync issues with pure audio signals. Typically, there is a “direct” setting that will bypass this processing and pass through simple stereo.

In this case, the receiver is the Sonos AMP. I have looked for a more direct setting on the TV for outputting audio. The only settings I have found allow for switching between Auto, Bitstream and Dolby. None seem to really make difference. Curious if people have found these types of settings listed elsewhere on their TVs.

When SONOS players are “Grouped” there is a 75ms latency. The latency is reduced to about 30ms for the TV connected to PLAYBAR/BEAM/ARC/RAY/PLAYBASE/AMP.

So on my Sonos settings, I see a Group Audio Delay of 75ms with no ability to go lower. I have a Sonos AMP hooked up to the TV with two Sonos Ones as Surround Audio. Should I be seeing an option for 30ms instead?

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The film industry dealt with lip sync in the 1940’s. I’m not convinced that TV stations even care. While standing in a TV master control room I remarked that there were some lip sync issues. The staff just glared at me as if to say: “you don’t get it”. In my experience lip sync can vary from channel to channel and program to program. Film channels seem to be the best.

 

Your point about TV here seems relevant as it does seem to be specific to live TV either over the air (an HD antenna) or through Chromecast (e.g. ESPN, Fox, etc.) and not really with pre-recorded stuff (e.g. Netflix, Hulu (not Live), Amazon). If that’s the case, does the mean the lip sync problem is inherent to the source signal here? And would it mean it’s actually totally unrelated to the Sonos and would happen even when outputting audio directly through the TV’s speakers?

 

Correct, lip sync is out of whack before the signal leaves the station. If there was a constant error, some sort of simple delay (not so cheap for video, but doable) in the home would easily fix the issue.

The film industry goes to a lot of trouble to keep the sound in sync. They’ll be using multiple cameras and microphones. A special timing track is included on each recording. You’ve seen videos of movie shoots where a “click board” is snapped at the beginning of each shot. This establishes a video and audio reference mark that allows synchronization of everything associated with that scene.

TV is simply a gaggle of cameras and unsynchronized microphones. TV stations care very much about the video signal and use elaborate schemes, such as controlling cable lengths to a fraction of an inch. Otherwise, there would be color shifts and jumpy pictures associated with each camera. They don’t care much about the audio. I’m not sure if anyone at the station would even notice if the audio was missing for a while. Currently, with work at home, the remote hosts are using PC’s and whatever to feed back to the station. Network delays and uncontrolled PC processing delays compound the lip sync issue.