Usb to 4pin speaker could not play sound

[manaism]

I use usb to 4pin speaker on jetson nx .
It works well when i connect the speaker on nx after boot.
but it doesn’t work when i connect the speaker on nx before boot.
lsusb command display speaker is connected and led in speaker turn on.

Could you have any idea about this problem?
Please give me a some advice.

[jonathanh]

Hello!

What command are you using the test the audio?

What do the following commands show?

$ lsusb
$ cat /proc/asound/cards

Regards
Jon

[manaism]

I found the answer.
When i connect hdmi cable to monitor and usb-to-speaker, jetson nx send out audio to monitor, not usb-to-speaker. even if monitor can’t make a sound.