I have an Asus K52Jc and in sound configuration there is no independent sound device for the headphones, and so there's no way to have independent volume for speakers and headphones.
Is there a way to have independent devices? Or is this hardware specific?
lshw reports that I have an "Intel 5 Series/3400 Series Chipset High Definition Audio".
aplay -l reports:
placa 0: Intel [HDA Intel], dispositivo 0: CONEXANT Analog [CONEXANT Analog]
Subdispositivos: 1/1
Subdispositivo #0: subdevice #0
placa 0: Intel [HDA Intel], dispositivo 3: HDMI 0 [HDMI 0]
Subdispositivos: 1/1
Subdispositivo #0: subdevice #0
If I'm understanding you correctly, it looks like that the device driver for your headphones isn't installed - Can you check to see if it's showing as installed?
This is what my output looks like, and I can have separate audio output/input for both speakers and headphone