What are Reference loudspeakers?

Ecoustics takes a look at what a loudspeaker needs to have to become a reference one:

Audiophiles and home theater enthusiasts regularly use the word "reference" to describe the qualities of a loudspeaker or an A/V component without thinking too much about the term. In certain contexts, "reference" may even be attached to an entire audio or home theater system, the implication being that "reference" equipment is about as good as it's possible to get, or that the sound quality cannot be bettered with existing technology. Read more at Ecoustics