i'd like to throw a vote out there for audioengine5 monitors. sure they're powered...but man do these little guys sound really, really good. they're extremely cheap too...swap out that tubed int for a tubed pre (or dac if it's coming out the computer) and you'll be in heaven.
http://www.macobserver.com/review/2007/03/29.1.shtmli'm listening with a pair right now...i alternate between these and sennheiser 650's...surprisingly i don't feel that disappointment taking off the cans and turning on these little guys that i thought i would. i have the volume controlled via computer, and they're being driven through a cal alpha d/a straight into the audioengine speakers. it's really, really surprising how such a reasonably priced solution can sound so good.
or, if you're firm on passive speakers, i'd like to also recommend dynaudio contour 1.1's. they're small, have clean bass...though i am partial to the dynaudio house sound in general (i love and have owned at some point the special 25, confidence 3, confidence 5). i saw a pair on agon sold for 800usd (obo) used.
well, happy hunting

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