A 5.1 question for the gurus


#1

Greetings audio format gurus I’d like to turn on 5.1 recording but doing so disables playback via one of my roku ultras that isn’t connected to a 5.1 capable device (Panasonic plasma TV, who’s hdmi input happily informs roku of this deficiency…)

Question is… what are the remedies? My Old tivo and DirecTV boxes must have down converted , and the broadcast signal itself must contain both pcs and ac3 cause i haven’t encountered this issue outside of tablo which (if I read correctly) is either/or and not both.

Anyway if Roku has to see a 5.1 capable device then I’ve got to either replace the TV or hang a cheap avr in front of it? Too bad… the old 1080p plasma is a good display.

Calibrations, corrections and advice gratefully received


#2

Can you just manually change the Audio settings on the Roku to “DD”? And see if it works. Sometimes the Roku device doesn’t detect what the TV is capable of properly.


#3

I did try that – the result is that Roku can be fooled in this way, but the downstream equipment is unable to play the audio (the episode of Chicago PD is silent). my experimental theory was that if Roku could pass the AC3 to the TV, then even if the TV itself could not play the audio track (via its own speakers), then perhaps its optical out might be an AC3 passthrough. So I plumbed the TV’s optical out into a Yamaha YAS-203 soundbar and that test was unsuccessful (no program audio). So the possibilities that would explain this are:

  1. the soundbar doesn’t decode AC3 either. that seams unlikely as it contains a DTS decoder and I’ve used the same soundbar before with 5.1 optical output from a newer TV and this works

  2. The Roku doesn’t pass the AC3 audio track when I set it to dolby digital (not auto detect). this seems unlikely to me because the same program episode of Chicago PD plays nicely on another Roku Ultra of the same age in a different room, where it is connected to a real AV receiver

  3. Roku passes AC3 via HDMI all right, but the TV trips over it and gives up without even passing the audio though to the optical out. the TV is a Panasonic 800U 50" plasma, FYI.

one result that I can’t explain is that the roku navigation sounds (clicks and beeps) DO play on the soundbar. So what is different about this audio information compared to the AC3 track supplied by tablo? why would the soundbar play those sounds but not the program track?


#4

maybe one of these would do the necessary magic to pass AC3 to my soundbar without involving the TV


#5

Which Roku Ultra do you have? Model 4640 has a built in optical out on the Roku.

Does your sound bar support / playback AC3 audio over optical?


#6

This is the one I have, it works well. It can extract the AC3 audio from the HDMI. This is an HDMI switch versus a splitter which is what you posted. Can take input from 4 devices.


#7

Another option:


#8

Gotta try the roku optical! Soundbar claims to support it yes


#9

Does your Roku have an optical out?


#10

Only the Roku 4 is only one I know that has an optical output
roku4-rear


#11

Original Roku 4 Ultra had optical out as well (not the new version… and thank you Roku for always using the same name for your devices).


#12

yea mine is a 4660x. no optical


#13

The only one has optical is the original Roku 4 the new one they just call it Roku Ultra no optical out you can see the name in front of them



#14

Again, the original Roku Ultra (4640) has optical out. The new Roku Ultra (4660) does not.


#15

Don’t think they ever call the Roku 4 as ultra, they describe it as having streams to brilliant 4K “Ultra” HD on 4K TVs


#16

Dude the Roku 4 is Model 4400, and the first Roku Ultra is Model 4640 - BOTH have an optical output on them. They are different units, no one here is calling a Roku 4 a Roku Ultra.

The 2 newer Roku Ultra models do not have optical out.

If you are still confused. Please read the wiki below:


#17

I’m the one that mistakenly said “Roku 4 Ultra”… blame me for that confusion.


#18

Not your fault, Roku’s fault with their dumb naming conventions.