actually, they're not the entry-level. there are the scm 7's, the scm 10's, the scm 20's, then the scm 50's. the only real minus of the 50's is that they roll off at about 32hz, and don't drop all the way to 20. everything else is truly the best i've ever heard. the highs aren't quite as sweet as really good electrostat panels, but very, very close. i wouldn't have laid down the money if i didn't truly believe that.
but, the passive and active scm 10's are great little speakers, though limited in bass response due to their size.
and, while we're on the subject of atc stuff, their electronics are also really, really good. i use their amps (obviously - built into the speaker) and their preamp, which is the most sonically transparent preamp i've ever heard. (granted, i haven't heard all that many, though) and the phono stage is also incredible. expensive but, again, at $8500, i wouldn't have bought if i didn't believe. and when i took the top off to set the phono stage portion, i saw why exactly is cost so much. having long built and repaired computers and electronics, i couldn't believe the quality of the assembly and quality of the parts. think of it as a top-shelf martini made by an experienced bartender. good stuff.
and, as for the 150's, 200's and 300's, they're really meant for studio use. if you had them in a normal sized house, they'd blow the windows. and i mean that literally. they won't sound any better, i wouldn't think, than a pair of 50's or 100's with an atc sub.
and, just fyi, the number (ie 7, 10, 50, 100, 150, etc . . .) refers to the enclosure space in liters. the 200 and 300 have identical drivers, but different enclosure spaces.
