Bug 291356 - USB Surround Sound with Audeze Mobius 3D 8Ch: voices and other audio elements seem to be stuck to the left channel only
Summary: USB Surround Sound with Audeze Mobius 3D 8Ch: voices and other audio elements...
Status: Open
Alias: None
Product: Base System
Classification: Unclassified
Component: usb (show other bugs)
Version: Unspecified
Hardware: Any Any
: --- Affects Only Me
Assignee: Christos Margiolis
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2025-12-02 16:40 UTC by Alexander Vereeken
Modified: 2025-12-08 13:50 UTC (History)
2 users (show)

See Also:

Attachments
sndctl -v (3.35 KB, text/plain)
2025-12-04 17:20 UTC, Alexander Vereeken 		no flags Details
mpv dvd:// (1.86 KB, text/plain)
2025-12-04 17:31 UTC, Alexander Vereeken 		no flags Details
sndctl -v (4.53 KB, text/plain)
2025-12-04 17:39 UTC, Alexander Vereeken 		no flags Details
dmesg (22.75 KB, text/plain)
2025-12-04 18:17 UTC, Alexander Vereeken 		no flags Details
Show Obsolete (1) View All Add an attachment (proposed patch, testcase, etc.)

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Description Alexander Vereeken freebsd_triage 2025-12-02 16:40:45 UTC 
Hello,

when I attempt to use surround sound, it does not appear to work correctly.

Specifically, I tested by playing a 5.1 movie from DVD using mpv, with the setting sysctl dev.pcm.X.play.vchanformat=s16le:7.1 applied. 

However, the voices and other audio elements seem to be stuck to the left channel only.

ugen0.11: <Audeze Mobius 3D 8Ch Audeze Mobius 3D 8Ch> at usbus0
uaudio1 on uhub0
uaudio1: <Audeze Mobius 3D 8Ch Audeze Mobius 3D 8Ch, class 0/0, rev 2.00/0.13, addr 18> on usbus0
Comment 1 Christos Margiolis freebsd_committer freebsd_triage 2025-12-02 16:43:58 UTC 
You are saying you are playing a 5.1 movie, but the vchanformat setting is 7.1. Doesn't setting it to 5.1 work?
Comment 2 Alexander Vereeken freebsd_triage 2025-12-02 16:48:12 UTC 
Thanks for your quick reply, unfortunately the same outcome.
Comment 3 Christos Margiolis freebsd_committer freebsd_triage 2025-12-04 11:20:46 UTC 
Please attach your dmesg, as well as the output of the following command *when* running mpv:

$ sndctl -v

If your FreeBSD version doesn't have it, then:

# sysctl hw.snd.verbose=2
$ cat /dev/sndstat

Also, you can try the following setting for your USB sound card:

# sysctl hw.usb.uaudio.default_channels=6

For the change to take effect, you have to re-plug your soundcard (see snd_uaudio(4)'s man page).
Comment 4 Alexander Vereeken freebsd_triage 2025-12-04 17:20:59 UTC 
Created attachment 265835 [details]
sndctl -v
Comment 5 Alexander Vereeken freebsd_triage 2025-12-04 17:31:06 UTC 
Created attachment 265841 [details]
mpv dvd://
Comment 6 Alexander Vereeken freebsd_triage 2025-12-04 17:39:33 UTC 
Created attachment 265842 [details]
sndctl -v
Comment 7 Alexander Vereeken freebsd_triage 2025-12-04 18:17:01 UTC 
Created attachment 265844 [details]
dmesg
Comment 8 Christos Margiolis freebsd_committer freebsd_triage 2025-12-06 14:16:11 UTC 
Is there any improvement if you set dev.pcm.X.play.vchanformat to s24le:5.1 or s24le:7.1? The latter is what your card actually uses.

Also did hw.usb.uaudio.default_channels=6 make any difference (remember you have to re-plug the device for it to take effect)?
Comment 9 Alexander Vereeken freebsd_triage 2025-12-07 10:49:40 UTC 
No improvement was observed when setting the format to either the device’s original configuration or to s24le:5.1.

I also re-plugged the device and set the vchanformat accordingly after adjusting hw.usb.uaudio.default_channels. Additionally, I tested with 8 channels to be thorough.
Comment 10 Christos Margiolis freebsd_committer freebsd_triage 2025-12-08 13:50:55 UTC 
Is this also a problem with another media player, or even another OS?