March 2009
I installed a brand new Ubuntu Intrepid desktop, but couldn't get teleconferencing via Spreed working: Firefox wouldn't pick up sound from the microphone. But now it works... [20]
Get the hardware and plug it in. [21]
Make sure you've got sound support at all: see whether the sound card is listed in the system settings (K->System Settings->Sound) (I'm using the KDE). Select the device you are using as the default device for all activities.
Get POC: try to find any application that will work with your headset.
Ekiga
(apt-get install ekiga) is one that will offer a menu to pick sound devices from, both for input and output, regardless of default KDE settings.
Its configuration druid can be restarted from the menu too :)
When you've got sound in Ekiga, find which devices it has open. Find the pid with ps axu|grep [e]kiga and list the open sound devices with lsof -p <pid>. Save these for later reference.
Firefox by doesn't heed the default set in the KDE sound configuration.
However, saying alsasoundconf set-default-card 1
fixed my case.
If firefox is still using the wrong device, you might want to have a look here.
If the above doesn't help, you might want to cat /proc/asound/cards to find out which values to set in a ~/.asoundrc
file:
pcm.!default { type hw card 0 } ctl.!default { type hw card 0 }