logitech speakers for ps3

hey, i was thinking of purchasing some speakers for my ps3, as my tv sound is awful.
To be precise, the ones i am ordering are the logitech x230 2.1 system, and what i would like to know is how could i connect them to the playstation. At the moment, my ps3 is connected to the tv using hdmi cable, and i've heard you can use the composite cable from the box to use as sound. However, i also heard that you need an adaptor to be able to use the composite cable into the speakers?
I was wondering if anyone could help me, saying what the adaptor would be, or any other options how to get them working?
Thanks for your help.

the white and red cable will work. they get connected to the back of the bass speaker. sometimes the cheaper ones wont have this for example the kinda ones u get in tesco. the connections in the bass speaker that connects to the dvd player will be what u connect to ur ps3 instead.

this works fine but if at all possible i would suggest you get a set of surround speakers that have an optical connection. optical is far better there is only 1 wire to worry about