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tvOS and Corresponding HDMI Firmware Version
- Thread starter Rok73
- Start date
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I fire up the ATV which is connected to my 4K LG SM8500 TV. The LG is connected to a Sony HT-ZF9 sound bar via eArc. Sound is being played for 10-15 seconds, then it’s gone. Gonna have to restart the sound bar once or twice in order for it to work.
All the devices are new, bought at the same time. Didn’t have this issue at first. All cables are HDMI 2.0. Tried factory reset on every device, didn’t help. Tried tvOS 13.4.5 beta today, nothing changed.
And, if I remember correctly, I have not seen HDMI Firmware Version to change for some time.
It definitely does not change with every tvOS update.
It definitely does not change with every tvOS update.
I’ve switched the port, rebooted, no change. Turned off Atmos, reboot, no change. The sound goes away after 15-20 seconds even when sitting on the homescreen.
i don’t get it because it worked just fine for a couple weeks with the exact same settings. I can also control the ATV with the LG TV remote, everything else works just fine.
i don’t get it because it worked just fine for a couple weeks with the exact same settings. I can also control the ATV with the LG TV remote, everything else works just fine.
Once again did a factory reset on the sound bar and tried messing with settings on the TV as well as the sound bar - one by one - followed by restarts of all devices each time to no avail. I've sent LG an email. Sony said they have no knowledge of these issues with their latest firmware 2.314 for the sound bar.
Mr. Zarniwoop
macrumors 6502a
Diagnosing HDMI connections and how they negotiate capabilities can sometimes be maddening because it's rarely clear what's really happening.
I suspect that TV doesn't support eARC (HDMI 2.1), although probably can do Dolby Digital Plus/Atmos over ARC (HDMI 2.0). Can you disable DD+/Atmos on the TV or Soundbar and see if it makes a difference? That would put you back to isolating the ARC connection as just working when the bitstream is lower bandwidth.
I would look between the TV and soundbar, as I don't believe the Apple TV knows where the sound is going, it just works with the HDMI sinc it is connected to. Assuming the Apple TV is plugged into a non-ARC HDMI port on the TV and the soundbar is on the ARC HDMI port on the TV, then the Apple TV is getting EDID info from the TV to know what sound format the TV reports as supported. If the TV is configured to send audio back to the soundbar via ARC, it's probably going to tell the Apple TV to send compressed audio bitstreamed (either Stereo or DD 5.1) rather than uncompressed multi-channel LPCM (even if "Change Format" is "Off"). But, if ARC is disabled, the TV may tell the Apple TV to send multi-channel LPCM? If something there is getting confused, I would think there's no harm to setting "Change Format" to "On" on the Apple TV to force it to bitstream audio just in case it's sending multi-channel LPCM which can't be passed back via ARC.
I tried “Change Format” already. Just to be clear: the sound just cuts about 15-20 seconds after turning everything on. A restart of the sound bar fixes it and all sound is output as it’s supposed to. I can check the current sound format on the bar with a press of a button. The sound bar supports these formats:
Dolby® Digital, Dolby Digital Plus™, Dolby® TrueHD, Dolby Atmos®, Dolby® Dual Mono, DTS®, DTS-HD High Resolution Audio™, DTS-HD Master Audio™, DTS-ES, DTS 96/24,DTS:X™, LPCM (2-Kanal/5.1-Kanal/7.1-Kanal), DSD (2-Kanal/5.1-Kanal)
The TV supports ARC HDMI 2.0 and These codecs:
AC4, AC3(Dolby Digital), EAC3, HE-AAC, AAC, MP2, MP3, PCM, DTS, DTS-HD, DTS Express, WMA, apt-X
However I found out that Sony added support for eARC (2.1)in that 2.314 firmware update a couple weeks ago. Maybe it has something to do with it. Since then it supports the following formats:
Dolby Atmos®-Dolby TrueHD® & DTS:X® or Multi channel LPCM content that can’t be transmitted over ARC.
No it doesn’t. Also, when I turn the sound bar off it automatically switches to the TV speakers. Switches back to the sound bar when I turn that on.
Last edited:
Audit13
macrumors 604
Sounds like an issue between the TV and soundbar. Not sure how to solve this other than trying another sound bar.
Mr. Zarniwoop
macrumors 6502a
Can you downgrade that soundbar firmware? Or otherwise disable eARC support on the soundbar since the TV can't do it anyway? That might solve it.
I turned off Atmos on the TV, sound still cuts out after 20 seconds, sound bar restart fixes it.
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I’ve looked for the previous firmware and it seems it’s not available anywhere. I wouldn’t know if it’s even possible to downgrade. Gonna check the sound bar settings once more.
This soundbar has 2 HDMI inputs, why do you want to mess with (e)ARC?
It only has meaning for internal apps anyway.
I’ve tried connecting the Apple TV directly to the sound bar HDMI 1. Then the picture randomly started getting black for a couple seconds...
EDIT: there’s also a PS4 and an IPTV set top box connected to the TV. It makes things easier.