HW-K650 and Two R1 Wirelss Speakers in 5.1 With KS7000 TV

[podavies]

When using the K650 sound bar and two R1 Wireless speakers in surround sound mode over wifi with the latest firmware, The quailty of the sound K650 drops, sounds very muddy. As soon as you use the sound bar on it own, the sound bar improves. this is happening for a quite a few users.

can you help.

[abob36]

Just to echo Simon, I too, have noticed the audio sync issues with optical which should not happen. It is much more pronounced than if you are on Wi-Fi. Also his experience with this kit matches mine as well.

[frustrated]

My setup is the same and behaves in the same way Simon describes. 

Is it possible that the problem lies with the tv not sending the correct data via HDMI or WiFi?

It would be interesting to hear if this 5.1 setup works with other brands if tv using arc HDMI.

[simon_w]

The transmission of audio over HDMI and TosLink (optical) are set down in internationally agreed standards so that they are compatible across all manufacturers and decoding chips. Notwithstanding any intermittency or sync issues the K650 can clearly decode the optical stream correctly - the actual data stream over HDMI should be identical. Testing this with a 3rd party sound bar should confirm this instantly.

The 5.1 over WiFi protocol is proprietary to Samsung and almost certainly recodes the data stream in some way to make it more robust to timing issues over Wifi - it is certainly possible that the problem lies with either the TV's wifi output or the soundbar's input - or even the surround speakers but I doubt it.

Perhaps Samsung would like to enlighten us as to exactly how the signals are transmitted - we know that all the devices are connected to the router or smart hub but which device is in charge of clock timing, sync and level...? Is the same multiplexed stream sent to all speakers and de-multiplexed locally or does each device only receive its assigned stream?

What we do know is that the basic multi room system does work correctly when being fed a 2.0 stream from a phone etc. The sound bar creates a faux surround version of the stereo signal and sends it to the rear speakers.

All our problems come from using a true 5.1 AC3 source from disc, stream or DVB.

If anyone is so troubled by this that they cannot sleep 😉 have a look at the Dolby 5.1 specifications on the Dolby website: https://www.dolby.com/us/en/technologies/dolby-digital.html - this will give you an insight into the complexity of the Dolby data stream and all the possible decoding pitfalls...

[DazzaP]

Thanks for joining the hunt for a fix on this! You mention the video/audio being out of sync, which is something that I've noticed too and it seems to vary greatly, depending on what you're watching. I've now set the audio delay to 40, which seems to have made the synchronisation correct most of the time. 

I wonder what other people generally have that parameter set to in their set ups? I don't recall seeing any previous mentions of the audio delay in this entire thread, but in the last week or so it had been driving me insane!

[abob36]

I have mine set to 0 although there was not much difference between it and 40. I think you are seeing it more or noticing it more perhaps because we are using ARC or Optical vs. Wi-Fi. Most of us here are not using Wi-Fi anymore just so we can get the clear 5.1, but the brings with it a host of other issues including out of sync audio.

[leelazer]

Hi all

I get delay over optical but in most cases can fix this by setting audio delay on my TV to 0. The exception to this is when watching 4K bluray on my xbox one s. This is an xbox problem though and should be fixed in the nee update. 

Lee 

[simon_w]

The problem with the audio delay is that it cannot correct for when the picture is ahead of the sound - only the other way round.

The adjustment of 0-40ms is only two frames at 50p or one at 50i/25p - most people can tolerate the sound being behind picture for as much as 2 or 3 frames - but when the sound is ahead of picture it is immediately apparent - this is why Samsung only offer audio delay.

In my setup, especially when streaming from Amazon or YouTube I get sound behind picture even with the delay setting at 0 - sometimes it is so bad that the offet is 10 frames plus - easily discernable and enough to make me throw things at the TV !!

Worth noting is that the the delay setting is per-input on the 7 Series TVs which is sensible as it may well vary from source to source.

[simon_w]

OK - the plot thickens...

With the latest update to the soundbar under certain circumstances I am now getting 5.1 over WiFi.

I have just played a Dolby test file which works correctly in 5.1.  This is an H264 MP4 file with Dolby AC3 5.1 surround and with the rear speakers at max and the sound bar at minimum it plays with pretty balanced surround.

You can download the file here: https://thedigitaltheater.com/index.php/dolby-trailers/ - it is the top one in the list - load onto a mempry stick and play via the USB on the TV.

This is exactly the sort of file engineers use to test setups are working correctly...

However other sources are not decoding in surround with the correct rear level...

Interested to know if others are seeing / hearing the same...?

[abob36]

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@simon_w wrote:

The problem with the audio delay is that it cannot correct for when the picture is ahead of the sound - only the other way round.

The adjustment of 0-40ms is only two frames at 50p or one at 50i/25p - most people can tolerate the sound being behind picture for as much as 2 or 3 frames - but when the sound is ahead of picture it is immediately apparent - this is why Samsung only offer audio delay.

In my setup, especially when streaming from Amazon or YouTube I get sound behind picture even with the delay setting at 0 - sometimes it is so bad that the offet is 10 frames plus - easily discernable and enough to make me throw things at the TV !!

Worth noting is that the the delay setting is per-input on the 7 Series TVs which is sensible as it may well vary from source to source.

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Same with me. Audio is behind, not ahead. Delay would need to be -50 or more for it to be synced properly. I would have thought being wired would be better for delays, but not with this system...

Simon, I have been getting 5.1 via wi-fi for a while now (at least since 3109 version and now the 3111). The issue is the volume of the rears. It is still too low even at -6 for the soundbar and +6 for the rears. Early on in the thread some of us passed around an AC3 5.1 speaker test which will clearly let you know if it is working or not.

[simon_w]

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abob36 wrote: 

Simon, I have been getting 5.1 via wi-fi for a while now (at least since 3109 version and now the 3111). The issue is the volume of the rears. It is still too low even at -6 for the soundbar and +6 for the rears. Early on in the thread some of us passed around an AC3 5.1 speaker test which will clearly let you know if it is working or not.

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Sorry abob36 - wasnt quite clear in what I meant by this:

To me it seems that files in certain codecs will decode properly in surround with rears at a workable level - the Dolby test file sounds exactly how I would expect it to.  I agree that this should be with front and rear speakers at 0 and not -6/+6 but even with that offset other sources are not decoding correctly.  To me this further suggets that the problem is not inherrent in the WiFi link to the rears but related to the way the soundbar is de-multipleing the 5.2 stream...

My point is that we are being told by Samsung's engineers that they have fixed it with the 3109 update - if the file they are testing with is one of the official Dolby test or demo files it may well be working for them...

Are you able to re-share the test file circulated earlier in this thread - or point me roughly to the right page?  I would be keen to try it out and see exactly what codec is being used.