"Line in" is an input on your normal computer sound card.clorwinf wrote: I have chosen "line-in" as the recording device and "Speakers 2 usb Audio CODEC" as the playback device.
"Speakers 2 usb Audio CODEC" is your USB speakers.
There is no direct connection between the two.
You can either:
1) Plug headphones/speakers into your normal computer sound card and set Audacity to playback through it (instead of to your USB speakers),
or
2) Enable "software playthrough" (near the bottom of the Transport menu)
Note that with option 2 there will be a slight delay (possibly around 1/2 second) before the sound comes out, but that should not be a problem.