one question....

i'm actually trying to play my PS3 on my LED monitor.....
but i do not have sound......and a quick check on my edifier R501 speakers 5.1 revealed that it does not support optical sound....
i dont mind not having surround sound......basic sound will do, but my speaker have 3 cables connected to the woofer which is orange, black and green.

so how do i get it to connect to the PS3 machine?......i've tried searching for connectors or TV box to connect but nothing yet
can anyone help or recommend me something?