|Well you're obviously wrong because it's working. The connection must have had crud in it or something, but it definetly is working.|
I believe what you're thinking of are these cheap solutions you can get where you have just two speakers and a woofer, by which the woofer simply amplifies the bass from the 2 channel sound.
The sound card in my computer is an amp essentially. If it wasn't, it wouldn't have the extra ports for different speaker setups.
Anyway it doesn't mater now, since it works, and I'm happy.