I own Europas and Quad 12L Actives. The problem is I haven't listened to my Europas in about a year and only recently got the Quads. And the Active 12's may be quite different from the passive ones, I don't know.
Rough impressions are that the Quads are more detailed and a bit more forward but probably don't image as well as the Europas and are not as open as the Europas.. I'd say the Quads, though very neutral, are a bit more "hi-fi" and a bit less refined. Funny because I would not describe the Europas as refined. Both are very good at low volume, with the nod going to the Quads.
Rough impressions are that the Quads are more detailed and a bit more forward but probably don't image as well as the Europas and are not as open as the Europas.. I'd say the Quads, though very neutral, are a bit more "hi-fi" and a bit less refined. Funny because I would not describe the Europas as refined. Both are very good at low volume, with the nod going to the Quads.