Reply to Hooking up KRK's to Audio 8 or just Laptop. HELP!

Hi I am looking to know how to hook these up correctly. I bought these very fast today because I was offered them at a price I could not refuse and seen them working in action etc. so I know there is nothing wrong with the speakers. However, I am having a couple of problems setting them up.

I have the KRK Rokit 5's, Audio 8 and a Macbook pro. I sound a bit dopey asking these questions because, in theory, I should know all of this. However, I thought this was the place to ask without judgment

I have tried hooking the Rokit 5's to my Audio 8 and play through Traktor, Ableton and made my macs sound settings to Audio 8 to play through iTunes and every time, there has been audio coming through but really distorted that any song is unidentifiable.

The only cables I have used for audio from the Rokit 5's is a standard RCA (Red & White) cables. I believe this is the issue but I am almost certain that I can connect these to the Audio 8 because there is no other possible outputs on the Audio 8 that I can connect to the Speakers.

I know that adapters will kill a bit of the sound quality so I want to stay away from these as much as possible and do not want to be buying any more expensive gear to make these work. I have also tried to get these working through my vestax mixer to no avail.

Any help would be great.

Cheers
M