I want to be able to record what my sound card outputs on the speakers / headphones. This question is all over the interwebs again and again, and there seem to be two outcomes:

• in your selection of audio input devices, there's a device called "Stereo Mix", or similar, which is the "loopback" device for audio. Choose that in your recording tool and you're done.
• there's no such device and only speculative posts about why that may be.

Now, I'm using ALSA and an Intel HDA chipset on my mainboard under Kubuntu Karmic. I have some 5-10 output channels and "Mic", "Front Mic" and "Line" for input. All of those are available in KMix, Audacity and other software. No "loopback" / "Mix" / whatever.

Do I have to

• get some driver / kernel module
• set up ALSA in some way
• set up my system configuration in some way
• use a software solution (such as JACK)

I had a look at JACK, and found it rather hard to understand, it's either an expert tool or just clumsy, I couldn't say. At least, I wasn't able to figure out how to achieve what I wanted.

One of my problems seems to be that I don't understand where and how the mixing happens. Are there sound cards which just aren't able to do it? Why does the sound card matter at all, since I could in theory grab the data stream at some point before it goes to the hardware, right?