I have the exact same speaker in both versions, the Paradigm Reference Studio 20 v2 and the Paradigm Active 20 v2. I hooked up the Studio 20’s in a biamp configuration to a Carver 505 5 channel amp (two channels driving L and two channels driving R) . I used quality speaker cables, set them up and they really sounded good, wide open soundstage from wall to wall.
When compared to the actives it feels you can drive the actives at lower volumes to achieve the same effect of being enveloped in sound. The bass extended down to 54hz in the passive, 36 hz in the active. The bass just doesn’t extend lower, it has a tight authority that really sings when you crank it. No mush, no softness, just a tight bass that drives along with the song with seemingly no effort. The tweeters seem to sing a little more effortlessly as well. If you didn’t hear them side by side you would be happy with the passive. After hearing the active the passive seems like drinking cold coffee compared to a steaming hot cup.
passive 20 specs
active 20 specs
http://www.cain.cainslair.com/Paradigm%20Reference%20Active%20Series%20Specifications.htm