You'll just need to look at the xlr inputs/outputs to see if they're male or female and go from there. For example, the XLR inputs on the Phonitor are female, so to connect via RCA I need RCA female to XLR male. On the other hand, the XLR outputs on the Phonitor are male, so to make use of those, I'd have to get XLR female to RCA female.
Yes correct but I see that there are several kind of XLR to RCA adapters (http://www.cardas.com/content.php?area=products&content_id=14&pagestring=Adapters&product_id=52)
I have an RCA cable and let's say I would like to transform it to an XLR one by using XLR adapters, so which types so I have to buy then?