Getting set up

[Lonn]

Probably a dumb question but......im learning to play and i picked up a roland rd-600 this weekend. Much better than the "radio shack" keyboard i was playing on! At this point i have been using ear phones to practice, what type of speakers can i use so that i can hear without wearing headphones? I see some guys on youtube using what appear to be stereo speakers. I tried hooking some up but i can barely here anything out of them. I have a sound system but i dont want to have to get all of that out and set up. Thanks for your help. Btw......i just hooked the speakers up into the mono out, should i hook them up differently?