I have an USB card, but the default card must be the onboard audio, i can change the default card in pulseaudio card, but i can't hear anything in Half Life 2, because the usb card is not the primary card.
$ aplay -l
**** Lista de PLAYBACK dispositivos hardware ****
tarjeta 0: NVidia [HDA NVidia], dispositivo 0: ALC662 rev1 Analog [ALC662 rev1 Analog]
Subdispositivos: 1/1
Subdispositivo #0: subdevice #0
tarjeta 0: NVidia [HDA NVidia], dispositivo 3: HDMI 0 [HDMI 0]
Subdispositivos: 1/1
Subdispositivo #0: subdevice #0
tarjeta 2: Headset [HP Digital Stereo Headset], dispositivo 0: USB Audio [USB Audio]
Subdispositivos: 0/1
Subdispositivo #0: subdevice #0
tarjeta 3: Generic [HD-Audio Generic], dispositivo 3: HDMI 0 [HDMI 0]
Subdispositivos: 1/1
Subdispositivo #0: subdevice #0