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KU6400 5.1 passthrough

Posted: Tue Feb 28, 2017 4:33 pm
by Gords
Im looking to pass through 5.1 audio from external hdmi sources connected to the tv into my 5.a amp via optical. I see a few reviews and peoples comments saying this is supported but my tv is telling it only forwards stereo. Is it possible this has been disabled via firmware at some point and is it possible i can reactivate via the service menu?

Thanks for reading.

Re: KU6400 5.1 passthrough

Posted: Tue Feb 28, 2017 4:48 pm
by zoelechat
It's supported. Proof (here KS7000):
2017-02-28-163931_1920x1080_scrot.png
No idea about lower ends though (looks to be same firmware so I see no reason), nor service menu (even if I don't remember such option...). Better check in normal menu first imho :)

Re: KU6400 5.1 passthrough

Posted: Tue Feb 28, 2017 7:35 pm
by Gords
I have same on my screen. Those options are there but when you get down to nuts and bolts its only stereo thats supported in those formats when passed from another hdmi device. I did some more reading today and it appears the tv is capable but that this function is normally blocked via the EDID data. Do you guys know any way of editing this?

Re: KU6400 5.1 passthrough

Posted: Tue Feb 28, 2017 8:16 pm
by zoelechat
I can tell you that it works out of the box here, are you sure your HDMI device is bitstreaming?
Indeed EDID had to be patched on pre-2015 series which were not supposed to support passthrough, but it needed root, lib for writing to EEPROM and so on, so no there's currently no such way to "edit" EDID on K :)

Re: KU6400 5.1 passthrough

Posted: Tue Feb 28, 2017 8:34 pm
by Gords
The reason ive assumed it isnt working is because in my windows machine its only giving me options to send stereo to the tv whereas my av receiver would give 5.1 and so on. i shall have a much more extensive play about tonight. looks like i can disable edid on the service menu pretty easily so may give that a try if i have no luck. what region model do you have by the way? mines a 55" uk.

Re: KU6400 5.1 passthrough

Posted: Tue Feb 28, 2017 8:51 pm
by zoelechat
Well, to be sure you still can check EDID using that tool: http://www.entechtaiwan.com/util/moninfo.shtm

Code: Select all

...
CE audio data (formats supported)
  LPCM    2-channel, 16/20/24 bit depths at 32/44/48 kHz
  AC-3    6-channel,  640k max. bit rate at 32/44/48 kHz
  DTS     6-channel, 1536k max. bit rate at 48 kHz
...
These formats are SPDIF max capabilities (no 6-ch PCM support!!), and imho it's expected that Windows reports 2 channels only (same here btw) since it outputs PCM, not AC3 nor DTS. Only test in real conditions (=bitstream 6ch DD/DTS audio of a movie) will tell, not just blindly trust what Windows says...
Otherwise my TV has nothing special: it's standard french UE49KS7000, and I don't think screen size matters for audio passthru ;)

Re: KU6400 5.1 passthrough

Posted: Tue Feb 28, 2017 11:50 pm
by Gords
You are very correct. After having a go with the xbox and setting it to bitstream/5.1 dolby (dts was a no go for the tv but that was expected) the tv did pass through the 5.1. Meaning its entirely a windows problem. Very glad i haven't got to bugger about with edid. Just need to find the best way to wangle windows into submission now :)

Thanks for the help.

Re: KU6400 5.1 passthrough

Posted: Wed Mar 01, 2017 12:24 am
by zoelechat
Use media player/codec (e.g. MPC-HC/LAV filters) supporting bitstream, simple as that. FYI DTS passthrough works as well :)

Re: KU6400 5.1 passthrough

Posted: Wed Mar 01, 2017 1:34 am
by Gords
Was hoping to get windows in general to run 5.1 for games if anything. Cant play those scary games without creepy noises from behind the sofa!

Re: KU6400 5.1 passthrough

Posted: Wed Mar 01, 2017 10:31 am
by zoelechat
It's possible, but you need a *real* sound card with either "Dolby Digital Live" or "DTS Connect" feature for real time encoding of multi-channel audio to spdif (or HDMI in your case, might be expensive...)

Otherwise it's possible in software way, but usually far from easy (real-time encoded audio driver has to be cheated, a bit kludgy)
https://www.reaper-x.com/2011/04/25/how ... -for-games
For reference, more Google research might show other possible setups, never worth capable HW though (low latency and resource consumption, sound quality, etc...).

How about simply and directly connecting your PC audio output to amp, via analog 5.1? :)