Speaker breaker bug in BETA

Plex Players Player Betas
1

Server Version#:
Player Version#:2026.18.0 (971050442)
This bug is brutal if you have surround with passthrough on. It could for sure blow the LR speaker. 5.0 AC3 is odd and obviously rare but it obviously does exist in libraries and that makes this a land mine. stable Plex played it normally, beta does not.
5.0(side) AC-3 files
NOT 5.1! Note, this is 5.0. I searched one folder and found another and it behaves the same on this version of plex.

To recreate:
Google TV (Onn Pro)<–HDMI–>5.1 AVR<–HDMI–>TV
Passthrough - HDMI
In bash i used the following command from my movie folder to find matching audio tracks:
find . -type f ( -iname ‘.mkv’ -o -iname ‘.mp4’ -o -iname ‘.m4v’ ) -print0 |
while IFS= read -r -d ‘’ f; do
ffprobe -v error -select_streams a
-show_entries stream=index,codec_name,channels,channel_layout
-of csv=p=0 “$f” 2>/dev/null |
grep -qi ‘ac3,5,5.0(side)’ && echo “$f”
done

If you have any of these files, TURN VOLUME TO ZERO BEFORE TESTING ON SURROUND.

2

Any chance you can reproduce and provide server logs after it happens? That would really help narrow down what is happening.

3

In the Plex app, browse your movie library. Change All to Audio Layout. Choose 5.0.

Can do same in TV library if you first change “TV Shows” to Episodes.

It will list all codecs, not just AC3, but no need for bash.

Is the audio direct playing?

Is it only the left and right channels?

Can you provide a sample file? It will help recreate the problem.

FWIW, I’ve five such movies. They all play fine. Using an onn Pro feeding a Denon AVR.

4

Sample PMed. If that still doesn’t reproduce I’ll get some logs.

I was wrong about the LR speaker. It’s so much treble at level 1 volume that my main objective is stopping it not diagnosing it. its coming from the front too.
Just testing in the “Plezy” app while I’m here. When using MPV the sound is normal, when using Exoplayer this bug is exposed.

5

Just as additional data point:
I tried to reproduce with a Shield (same Plex app version) and a soundbar. Passthrough is enabled, so AC3 and DTS should be decoded by the sound bar. I have tried the two 5.0 videos I could find and they play as expected.

6

I’m 3 for 3. AC3 5.0 goes crazy. The sample I sent does have channel issues. FordGuy61’s library filter gave me a 5.0 DTS file as well, it played normally with no issue.
Again, I have now implicated Exoplayer with Plezy. Someone above mentioned server logs helping but I doubt that. Would client logs help?

7

Thanks for the sample file. It plays normally on my system. The left and right channels are at normal levels, as are the others.

Maybe check your AVR? Do you have a sound field enabled that might be doing some extra processing?

Not doubting what is happening with your setup. Just cannot replicate the problem.

Here’s my setup: onn 4K Pro → Denon AVR-X4300H → LG B7 TV

Also used a Nvidia Shield Pro and AC3 5.0 played OK.

8

image
From the same Plex server, played in Plexy with MPV player instead of Exoplayer, sound is normal. Technically mpv player could be decoding and not passthrough though I’ll try to figure that out.
But no, I don’t think it’s a setting. AVR might be the wrong word, it’s a Vizio Atmos bar with satellite rears. In 4 years, including the sample file, it didn’t do this. I realize Exoplay is outside of Plex’s scope but hopefully there could be a Plex mitigation if this can be figured out.

9

Had to update Plezy to get MPV to passthrough and not decode. That reproduces the bug.
The issue stands that these videos played properly in this same setup just weeks ago and now they don’t. The soundbar hasn’t had a firmware update in 4 years. It has no new issues other than 5.0 AC3. The TV hasn’t changed and is also not getting firmware.
I need to test an old Plex client I guess? I wonder if it had a mitigation that the new client doesn’t.
My avr/soundbar remote hasn’t had batteries in years. I might try a factory reset on it if i can figure out how.

Something other than the hardware has changed though.