I actually just did this to my set. I have had this logitech speaker setup for well over 5 years now, and I just early yesterday morning thought to myself...wonder if adding 2.0/2.1 speakers would work. For my setup, it did. I simply plugged the 5.1 into three of the jacks (I selected Center/sub (orange), Rear (black), and Side (green cable plugged into grey due to the 2.0 speakers having shorter wire). Then I simply added the 2.0/2.1 speakers into the green jack. You will need to play with speaker audio levels on your computer, but for me, they worked well. I tested in Fallout New Vegas and Batman A.A. and it was great. Can't believe I didn't try this earlier.