Jasper's plugin didn't work for me (I didn't try much, felt too complicated).
I also tried a program called "virtual audio cable" - but is shareware and had someone say "shareware" every 30 seconds (pretty annoying) - didn't buy it.
The minijack Y splitter, on the other hand, worked like a charm - but not after some adjustments.
1. Before plugging any cables, make sure your stereo equipment is turned off since this setup can cause feedback, if not properly configured.
2. Then, you HAVE to plug in the cables for the motherboard to detect it. I was doing a 6 channel output setup (5.1 surround) so the minijack Y splitter was plugged in the "front pair" jack, and had a cable go to the line-in at rear panel.
3. Once everything is plugged-in: In Windows 7, open the recording devices, select the "line in at rear panel", properties, under the "listen" tab, check the box "listen to this device". Under the "levels" tab, bring that to around 80%. Click OK and close sound options. Open the volume mixer and lower the "Line in at rear panel" level to 0%.
4. It is now safe to turn on your stereo equipment.
5. In Winamp
, open the following URL in your playlist: linein://
Now, whatever plays through the front speakers will go back through the line-in and you will be able to enjoy visualisations with any audio streams...
Needless to say, our Diablo 3 venue was a complete success.
P.S. I wish i could post a picture of our setup, but it says that my 30kb .jpg is not a valid image file...?)