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Källa for TV sound

Posted: 2021-10-26 13:28
by Azazello
I have an LG OLED-tv that I have currently connected to Sagatun using the headphone jack and fixed output from the TV. Can I remove this cable and send picture (to the TV) and sound (to Källa) directly from my Ipad? Feels like a bummer to loose the smart-TV interface, but might be worth it to improve Sound quality? Will the picture suffer and/or will that introduce lipsync-problems? Would an Appe TV be a better solution? If so: how would the TV-interface look?

I need it to work for Netflix, HBO, SVT Play and YouTube.

Also thinking that the TV/Källa-thing might merit a thread on it's own :)

Re: Källa for TV sound

Posted: 2021-10-26 14:13
by jajo
I use an Apple TV with tvOS 15.1 and superb results. I have a Philips 65" OLED TV. It should work fine regardless of TV since the synchronisation is done between Apple TV and Källa. There is also an automatic A/V sync feature in Apple TV that uses the microphone in the iPhone to measure delay. I haven't had any reason for doing the automatic adjustment since it was perfect without it, but it might come in handy if A/V is not properly synced.

The only issues I have found so far when sending audio from Apple TV to Källa are:

* tvOS 15.0.* is very buggy, upgrade to 15.1 for proper playback with Källa (pre-15 also works fine)

* The Youtube app sometimes stops playing when I start a clip from the Youtube interface on Apple TV. There is a workaround: if I select Apple TV as output device on my iPhone and start the clips in the iOS Youtube app it never stops and audio is still routed to Källa properly

* There is a slight delay in the starting of clips when Apple TV and Källa negotiates the A/V sync. It is about a second and not really a problem, but maybe worth mentioning.

Also movies from the Apple TV rental store looks and sounds amazing, a good alternative to bluray even for my critical eyes. Also works great with 4K and HDR.

Re: Källa for TV sound

Posted: 2021-10-26 18:51
by Spannko
That’s absolutely fantastic news! I bought a KEDSM just so I could feed the TV through my system. Unfortunately, although the sound was very impressive, there was a complete lack of musical coherence, to the extent I found it unlistenable!

Re: Källa for TV sound

Posted: 2021-10-26 21:38
by Azazello
jajo wrote: 2021-10-26 14:13 I use an Apple TV with tvOS 15.1 and superb results. [...]
Thank you jajo, that was great news!

Re: Källa for TV sound

Posted: 2021-10-26 22:57
by macrotech2
Thanks Jajo. I also have an LG OLED connected similarly to Azazello, though I use the TV optical out into a Chord Mojo DAC which then feeds the Sagatuns. A significant improvement on the TV’s internal DAC. It sound like Apple TV might be worth a try to improve the sound even more.

Just thinking of making it wife friendly though. I currently control everything using a Logitech Harmony Elite remote. Does Apple TV remember it is Airplaying to Källa, or does this have to be set every time?

Re: Källa for TV sound

Posted: 2021-10-27 00:42
by jajo
macrotech2 wrote: 2021-10-26 22:57Does Apple TV remember it is Airplaying to Källa, or does this have to be set every time?
You can connect several control points to Källa and I haven't noticed any reduction in performance caused by multiple connections. Most of the time they can remain connected for a very long time and as long as you don't try to play from two at once, switching control point (Apple TV included) works just fine without having to reconnect to Källa. You need to do a full stop of playback and not just pause for the connection to be freed up and available for another control point.

It is really convenient.

Although, I would advice to teach your family members how to reconnect if necessary. On Apple TV it is very simple. Just hold down one button for 2 seconds, click the Airplay icon and select Källa.

Re: Källa for TV sound

Posted: 2021-10-27 07:38
by macrotech2
Thanks Jajo.

Re: Källa for TV sound

Posted: 2021-10-27 09:55
by fredrik
Thanks jajo for sharing apple-TV->Källa experience.
Is there a way for Källa to play Smart TV apps, playstation, sound or regular TV-channel sound?

Re: Källa for TV sound

Posted: 2021-10-27 11:19
by jajo
fredrik wrote: 2021-10-27 09:55 Thanks jajo for sharing apple-TV->Källa experience.
Is there a way for Källa to play Smart TV apps, playstation, sound or regular TV-channel sound?
It needs to be an app on a iOS, iPadOS, macOS or tvOS device playing the sound.

Re: Källa for TV sound

Posted: 2021-10-27 17:05
by fredrik
jajo, did you ever try to route sound from those apps/channels to the Apple TV though eARC and then apirplay to Källa?

Re: Källa for TV sound

Posted: 2021-10-27 22:23
by jajo
fredrik wrote: 2021-10-27 17:05 jajo, did you ever try to route sound from those apps/channels to the Apple TV though eARC and then apirplay to Källa?
Not sure how you mean. Apple TV does not allow incoming sound through HDMI?

Re: Källa for TV sound

Posted: 2021-10-27 22:43
by macrotech2
This link suggests it may be possible https://support.apple.com/en-gb/HT207117

Re: Källa for TV sound

Posted: 2021-10-27 23:15
by jajo
macrotech2 wrote: 2021-10-27 22:43 This link suggests it may be possible https://support.apple.com/en-gb/HT207117
Interesting, had no idea it had such a feature. I will surely try it tomorrow. It does say it only works with HomePods but maybe it works to Källa too. Will report back tomorrow.

Re: Källa for TV sound

Posted: 2021-10-28 00:22
by jajo
Had a chance to try it tonight.

This feature unfortunately only works with HomePod. Källa can only be selected as a "Temporary Audio Device" and not a "Default Audio Device" and because of this the eARC option does not appear.

Re: Källa for TV sound

Posted: 2021-10-28 05:41
by macrotech2
I suspected as much but I had my fingers crossed. Thanks for letting us know jajo.

Re: Källa for TV sound

Posted: 2021-11-15 12:08
by macrotech2
I decided to try an Apple TV with my LG E6 OLED. The picture and sound through Airplay are good. Sound is definitely better than the LG optical out into a Chord Mojo into the Sagatuns, particularly noticeable on musical content.

However, I have an insurmountable problem. The Airplay sound through Källa is slightly ahead of the picture and there is nothing I can do to fix it. Apple do provide a calibration routine but the calibration tone is not audible over Airplay, only when the Apple TV is set to TV speakers (the tones when navigating the menu are also not audible over Airplay). Using the calibration routine with the TV speakers doesn’t help.

Any suggestions? The Apple TV software is fully up to date.

Re: Källa for TV sound

Posted: 2021-11-15 13:53
by springwood64
macrotech2 wrote: 2021-11-15 12:08 However, I have an insurmountable problem. The Airplay sound through Källa is slightly ahead of the picture and there is nothing I can do to fix it.
Unfortunately I hit this same issue with Apple TV and my Hakai. Frustratingly it had been working fine for months, and then overnight switched to audio ahead of video. I was unable to overcome this and had to abandon AirPlay from my Apple TV for audio.

Re: Källa for TV sound

Posted: 2021-11-15 14:23
by lejonklou
It seems we have an unexpected lipsync problem with Apple TV.

We're reserved time to investigate this at the end of this week.

Re: Källa for TV sound

Posted: 2021-11-15 20:48
by macrotech2
Thanks Fredrik.

I think it's an Apple TV issue though, nothing to do with you. Mind you, if you can fix it that would be fantastic.

It seems there was a general problem with Airplay sound ahead of video on iOS15 as described here. https://discussions.apple.com/thread/253181517?page=2
But the thread says 15.1 fixed it and I’m running 15.1.

Re: Källa for TV sound

Posted: 2021-11-17 20:16
by ThomasOK
macrotech2 wrote: 2021-11-15 20:48 Thanks Fredrik.

I think it's an Apple TV issue though, nothing to do with you. Mind you, if you can fix it that would be fantastic.

It seems there was a general problem with Airplay sound ahead of video on iOS15 as described here. https://discussions.apple.com/thread/253181517?page=2
But the thread says 15.1 fixed it and I’m running 15.1.
Well, you know how these things go. By 15.3 it might really be fixed. ;-)

Re: Källa for TV sound

Posted: 2021-11-18 20:23
by macrotech2
springwood64 wrote: 2021-11-15 13:53
macrotech2 wrote: 2021-11-15 12:08 However, I have an insurmountable problem. The Airplay sound through Källa is slightly ahead of the picture and there is nothing I can do to fix it.
Unfortunately I hit this same issue with Apple TV and my Hakai. Frustratingly it had been working fine for months, and then overnight switched to audio ahead of video. I was unable to overcome this and had to abandon AirPlay from my Apple TV for audio.
I may have found a possible solution Pete. Try running the Apple TV audio calibration holding your phone at increasing distances from the TV.

Having done further listening, TV sound through Källa
Is far superior to Optical out through Chord Mojo.

I suppose a further solution is a settable delay in the Källa software, but I presume that would cause a sonic degradation.

Re: Källa for TV sound

Posted: 2021-11-20 14:50
by lejonklou
Very clever of you, macrotech2!

We have investigated the lipsynch issue. It appears to be working exactly as intended.

When Apple TV is connected with HDMI to a TV, the TV will tell the Apple TV how much delay its picture has. And the Apple TV will then make sure it sends the audio with the appropriate time delay. No bugs found in this.

One possible bug would be if the TV doesn't communicate properly with Apple TV about the delay. Really old TV sets could have this problem. I have an old Panasonic plasma (one of the last models before they disappeared) and it works fine.

We did find that I had slight lipsynch issue on my Apple TV (running on tvOS 15.1.1) to Panasonic plasma. We tried adjusting it to perfection, but it still wasn't perfect. Then we removed the calibration in Apple TV and lipsynch became perfect! Maybe something to try if you still have a problem?

I can also confirm that delaying the audio in Källa is not good for performance. There are several ways of doing it, but none that doesn't make Källa less musical.

Re: Källa for TV sound

Posted: 2021-11-20 15:13
by macrotech2
Thanks for investigating and for the update Fredrik.

The sync is better but still not perfect. I’ve tried removing calibration completely a while ago but will give it another try later.

Re: Källa for TV sound

Posted: 2021-11-20 15:55
by jajo
It can also be good to make sure to disable all "picture improvement features" on the tv as they can introduce delays that aren't accounted for in the processing delay in the EDID output of the display. Such features can be sharpness/upscaling or motion smoothness.

The reason why lipsync is rarely an issue when routing audio through the tv is that it knows of its own delays and then adjusts audio accordingly.

Re: Källa for TV sound

Posted: 2021-12-06 12:06
by macrotech2
A further update. Lip sync is still an issue but, interestingly, it depends on the picture format. It seems that only Dolby Vision streams have the sound ahead of picture issue. HDR steams are fine. Something to do with the amount of picture processing required perhaps? Irritatingly I suspect there’s nothing I can do about it. All picture processing features are turned off.