Many of the affordable studio monitors have a pretty high noise floor, especially when using the unbalanced RCA inputs. At a distance, you might not be able to hear it, but up close, you will. How much of a tolerance do you have for a hiss? If it is zero, I would just look for some passive speakers. Also keep in mind, these speakers don't have remote controls and typically must be turned on from the back panels. That might be a real inconvenience for some people.
If you want some affordable passive speakers that have a nice flat response, look at the Polk Reserve R200 speakers. They are pretty neutral and shouldn't break your bank.