When you run music applications and games at the same time on Windows 11, the music sound may become smaller. This is caused by conflicting audio settings or applications used by the game.

Here are some suggestions to resolve this issue:

1. Adjust the volume settings: Make sure the volume settings are not adjusted to a lower level. You can adjust the volume by clicking the volume icon on the taskbar.

2. Windows Audio Settings: Open System Settings, click "Sound", and then select "Application Volume & Device Preferences". Make sure the volume settings for your music apps and gaming apps are appropriate, and adjust the balance between them.

3. Enable audio mode: Go to Windows 11 settings, click "System", and then select "Sounds". In the "Preferred Output Device" section, try switching to a different audio mode to see if there is an improvement.

4. Turn off audio enhancements: Sometimes, some audio enhancements may cause volume issues. You can go into Control Panel, click on "Sound", and then select your speaker device. In the Performance tab, uncheck "Enable audio enhancements."

If the above method does not solve the problem, you can try upgrading your audio driver or contact the Windows 11 support team for help.

I hope these methods can help you! If you have any further questions, I'll be happy to help.