I actually use two pairs of Altec Lansing speakers a pair Series 100's as the front channel. When used with the VS2121 2.1 speaker set as the back channel. I've listened to more than one manfactured system. That doesn't have the same sound quality I get my little home brew 4.1 rig.
The nice part both of the sets of speakers I used are reasonibly priced the whole setup cost me about $75 including the extention to move the back speakers furter away from the main system.