Problem

I have installed a sound card, but I can’t sound any sound, or I hear sound but not in all speakers.

Solution

To solve it, try first to review if your volume for all speakers is right.

Step by step

  1. Open a Terminal and execute the command alsamixer\

    If you need to install alsamixer, you can type:
    sudo apt-get install alsa-utils

  2. You can use F6 to choose your sound card. Set volume for all speakers.

If your speakers not still working, try this recommended steps:
https://delightlylinux.wordpress.com/2017/01/13/experience-better-sound-in-linux-with-the-asus-xonar-dx-sound-card/

Source

https://askubuntu.com/questions/598759/asus-xonar-dgx-recognized-but-no-sound https://www.muylinux.com/2019/04/15/calidad-sonido-linux-asus-xonar-essence/