These are the steps to configure FreeBSD to record audio from the sound card. This assumes you've got a supported sound card. This is an easy process but it took me quite a bit of trial and error to work out the details.

First, you'll need to enable your sound card. You could build a custom kernel with it as a device but the easiest way is to load a kernel module. To do this, is adding the following line to your /boot/loader.conf file:

Now reboot, and check that /dev/sndstat shows your soundcard:

See the Setting up the sound card section of the FreeBSD handbook for more info.

These packages are handy to install:

• audio/aumix - a nice curses based mixer
• sysutils/mixer - it saves your volume levels.

Next, you'll need to tell mixer what to use as your recording source. In this case we're using the line input:

Now you need to set the recording level:

After you get the stream up and running you'll want to open in WinAmp (or something with a spectrum analizer) and tweak the rec level so it's not clipping.

I wanted to make sure that no other audio gets encoded into the stream so I set the levels for all the other channels to 0: