Split headphones and internal speakers

When the jack is inserted the internal speakers stop making sound and the only analog out is the jack, as it’s common on laptops. But I want to address the two analog output individually so that I can:

  • Still select the speakers when headphones are plugged
  • Have different sounds come from headphones and speaker
  • Mix them with carla or other audio software

My alsa/pipewire settings are all default, I’m on a thinkpad t480s with fedora 38. My sound card is an intel hd audio card, with a realtek ALC257 analog chip.

I tried disabling auto_mute and rising the volume from alsamixer but nothing happens. Then I switching pipewire to “pro audio” but it doesn’t separate the analog outputs. I also tried setting the indep_hp hint from hdarackretask but it doesn’t change anything.

The hint enables a new “independent hp” option in alsamixer, but it can only be enabled by the cli and it doesn’t work either.

I can provide configuration files and other info if needed but since they are all pretty long I didn’t include them in the post. Also because I didn’t edit them so they are just fedora’s default.

I don’t have your hardware for testing, but in the past it has been common practice to have a hardware switch that disabled internal speakers when the headphone was plugged in.

Many newer systems carried that over to a software sensing when headphones are plugged in and perform similarly.

If yours is software controlled then what you wish may be possible, but if hardware switch controlled then it would not be possible.