I had the same problem with my brand new Dell last May. I didn't buy the dell speakers cause I figured my little polk HP speakers would work...and they don't.
I even had a guy come out and replace the motherboard (on Dells $) because Dell claims that that speakers should work, so they thought it was a sound card issue. The HP speakers still didn't work...well, they did, but you could barely hear out of them.
Finally I borrowed a pair of DELL speakers...and guess what, they work PERFECTLY. BUT...you have to have them plugged into USB and the GREEN speaker jack on the back...and you have to have ALL your sound settings turned to the max..and the speakers have to have a volume knob. Then you can finally hear out of them.
I haven't tried other speakers with my Dell Inspiron 530...
But my guess would be, that any speakers work, as long as they have a volume knob on them.
*EDIT* I should also say, I got a BROKEN keyboard with my new dell, and the USB plugs in the front didn't work...all this brand new out of the box. Thankfully they fixed everything very quickly. But my first shopping experience with Dell wasn't a good one.
Edited by Kat91119, 24 July 2009 - 01:09 PM.