AppleTV 4 surround sound issue

jvulto wrote:

However, surround back speakers do not produce sound 😟.

Does the app Theater Test id your rear channels?

just installed the Home Theater test (thanks Bodosom).

when having the surround setting set to 'auto' the receiver detects 7.1 PCM input 3/4/.1

THe App detects 8 speakers, so far so good!

THen however during the test all speaker signals are mixed up. Rear channels direct to subwoofer, left surround to center etcetera.

the App hints to a problem of mixed signals. Workaround would be to set the Dolby Digital stting to 'ON'. However this setting does not exist in ATV 4.

when setting the ATV to surround mode 'auto', the App only detects 5 speakers.

HELP!

On auto setting theater test has my speakers all mapped wrong. On dolby digital they are mapped correctly. I know speakers are hooled up right. Ihave a pioneer elite sc-85 if that helps anyone. When I had roku dolby digital plus worked fine on netflix. Never get that anymore in apple tv 4

@Mike: With Surround mode set to "Dolby" in stead of "auto" does your receiver also detect only 3/2/.1 instead of 3/4/.1?

So far you describe the same issue as I seem to have.

I had channel problems as welll but since I don't have rear channels configured I wasn't sure if it the app or my audio setup. I left a two star review and sent mail to the developer.

yes, only sees 3/2/.1

I posted this elsewhere:

I initially thought the ATV 4gen was decoding everything and sent PCM. This is because my AVR has both OSD and web interfaces and reported two different values* for the input signal from the ATV 4gen. It's now clear that when Surround Sound is set to Dolby Surround an AC-3 signal is generated however the bitstream from a model ATV5,1 (ATV 4g) is not the same as the bitstream for the same input a model ATV3,1 (ATV 3g). The "dialnorm" meta-data has been removed which means it is modifying the bitstream. I don't know if it's possible to do that without a decode/encode step.

The ATV 4g is decoding everything in AUTO mode and it's not possible to know what the original bitream contained. Since we now have a report of content in rear surrounds (from Terminator G) I vote that it's working as expected rather than Apple artfully creating fake surround data and that means E-AC-3 is being used for transport.

Why? then, is it that, when I use Apple Music does it light my DD light on my 5.1 sound bar when ATV 4 is set to AUTO, the ATV 2,3 didn't and my sound bar would apply a surround effect to it. This is what bothers me the most, soon as my sound bar detects DD it will not apply the surround effect and music doesn't sound as good.

I posted here a while back and have figured out my issue I have multiple audio streams in some of my encoded movies, and found that you can detect them in the audio pull down once the movie has started. My dolby surround issue is gone, but the more pressing issue is the fact that the new ATV4 is not outputting the full dynamic range even when set to do so. It is muting the loud noises even when the output in the dropdown is set to "full dynamic range" this needs to be fixed asap or the new apple tv is a no go for me and will be returned.

Steve Waite wrote:

Why? then, is it that, when I use Apple Music does it light my DD light on my 5.1 sound bar when ATV 4 is set to AUTO, the ATV 2,3 didn't and my sound bar would apply a surround effect to it.

I don't know. Apple Music does the right thing (produce stereo) when I use it as does iTunes Radio (the closest thing to Apple Music). Both send 2-channel PCM. What happens to that signal depends on my AVR settings. I leave it at stereo but I have a variety of surround modes to choose from.

I am having the same issue. I have called Apple tech support and was told to reset the ATV 4. This did resolve my issue but only for a few days and now the audio output is incorrect again. My Onkyo receiver will detect a stereo 2 ch signal and automatically switch to stereo mode, or back to Dolby Digital when watching a movie. After a couple of days of using the ATV4 my receiver only says multi-channel. Again, I reset my ATV4 and the problem is resolved with sound outputting the way it should but only a for a day or two.

My receiver is an Onkyo TX-NR616, with the latest firmware upgrade (thought maybe it was my receiver). If I plug in my ATV 3, I have no audio problems and everything plays the way it should. Movies and music sound like crap because the receiver is not able to output correctly with mixed channel output coming from ATV4.

Really disappointed that Apple could not get this right as it worked perfectly on ATV3. I don't want to keep factory resetting the unit every few days to get the auto sound output working correctly.

Also, to the users who have forced the setting to Dolby Surround in the ATV menu, you are not getting true Dolby Digital sound, this just tricks your receiver to show Dolby Digital but not all channels output correctly as another user has stated.

"Also, to the users who have forced the setting to Dolby Surround in the ATV menu, you are not getting true Dolby Digital sound, this just tricks your receiver to show Dolby Digital but not all channels output correctly as another user has stated."

There is several threads about this at MacRumors. I hope Apple fixes it soon. It is horrible. I will use my Roku until it is resolved

JMac12 wrote:

Also, to the users who have forced the setting to Dolby Surround in the ATV menu, you are not getting true Dolby Digital sound, this just tricks your receiver to show Dolby Digital but not all channels output correctly as another user has stated.

This is not true. Multiple people using multiple tests have shown that setting Surround to Dolby plays AC-3 soundtracks correctly.

You can:

1) Use the Netflix test video

2) Use any AC-3 test track you've loaded into iTunes.

3) Use the Surround Speaker Check app.

I've done all three and AC-3 works correctly with Surround set to Auto or Dolby.

when ste to auto after you reset does your receiver show Dolby digital or pcm? My pioneer my shows pcm. Hope they straighten thisout as except for this I do like the Apple TV better than the roku. Plex is a much better looking app on here.

Why? then, is it that, when I use Apple Music does it light my DD light on my 5.1 sound bar when ATV 4 is set to AUTO, the ATV 2,3 didn't and my sound bar would apply a surround effect to it.

The TV4 "Auto" unconditionally opens a DD+7.1 compatible PCM connection over the HDMI interface. It doesn't care if the source data is center channel mono, 2-channel mono, stereo, Pro Logic II, DD5.1, or DD+7.1 audio. The order units were not DD+ compatible and applied Dolby or "non-Dolby" decoding as needed depending on the sourced audio.

This is what bothers me the most, soon as my sound bar detects DD it will not apply the surround effect and music doesn't sound as good.

In that case, try setting the TV4 to the "Stereo" mode. This should allow "Sound Effects" or Dolby "Pro Logic II" decoding to be applied normally to your music. Just remember to "Auto" or "Dolby Surround" as required/preferred for multichannel surround audio sources.