I use these speakers as well with onboard sound. I like them a lot. My wife comes in all the time and asks me to turn them down. A lot of bass if you are looking for that.
AMD 64 3200+, Asus K8N-E Deluxe Mobo, Evga GeForce 6800 Video Card
1 GB Cosair Value Select RAM, 250 GB Seagate Baracuda HD
RaidMax Scorpio 668 Case w/ Aspire 520W PSU
Windows XP Home Edition SP2