ATSC 3.0 no surround audio

Noticed today that the 3.0 stations have almost no surround sound. Switching back and forth between 1.0 and 3.0 on the same station there is a HUGE drop in levels on the rear channels to the point they can hardly be heard. Shows that have very prominent rear audio are not coming through that way in 3.0.

Is this due to the experimental ffmpeg audio decoder?

Does it work in the official HDHR app?

What market are you in? Chances are the station is not yet broadcasting correctly.

They are, Director of Engineering at the lighthouse station says all channels come to him in 5.1 surround by direct IP feed from stations in the market (Charlotte)

Ah, downloaded the HDHR app and same issue. So either the station has a config issue or it’s something with Apple TV decoding audio stream.

Please make a 90s recording from one of the channels then email the mpg file to [email protected]

Ok, when prime time shows come on later I will do that.


Did the file reveal anything of interest?

Please submit diagnostics after playback of the recording as well.

During playback if you swipe down and go to player options, does it show one or two audio tracks? Does switching audio tracks make any difference?

Says Track 1 and Track 2. Swapping them does not change results.

Please submit diagnostics afterwards

Will need to record a new clip, deleted that one.

Just play live then.

New file and diagnostics sent

I need diagnostics from the client app after playback.

Sent that now

It is not immediately clear what's going on. Could be a configuration issue on the station side, or a decode issue on the ATV.

If you go to Settings > Support > Test Surround do you hear the sound coming out of each speaker correctly?

Yes. And I get surround on all other sources including the 1.0 versions of the same stations

Ok, I have to retract and clarify my statement on audio. Upon some digging around in the silicon dust forums it seems that the Apple TV is to blame. No current app for ATSC 3.0 is currently getting properly mapped audio in the ATV. Others see (hear) exactly what I do, no surround and center channel being mixed into the right front channel. This happens on HDHR or Channels app. So it’s an Apple bug.

But, when I load the HDHR app directly on my LG OLED and feed that to my system I get full surround and proper channel mapping.

I've got an ATV and my atsc3 stations work great with channels and 5.1