When I bought my first SET amp, (Viva) I almost immediately thought of trying one of those single-driver speakers, just to see what it's all about. I ended up buying a pair of Fritz FR6 because they were simple, inexpensive ($450) and fit on the 20" Epos stands I already own. I was previously using a pair of Opera Callas monitors (87 db) which I really liked. One thing I liked about the Viva was its ability to drive "normal" speakers like Harbeth, Sonus Faber, Opera, etc. to moderate levels, which is the level I listen at.
I've used the Fritz(s) for about 2 weeks and I really like them. The bass is definitely sufficient and they just sound good with the type of music I listen to. I then decided that I fooled around enough and decided to put the Operas back. This morning, I put on a copy of the Sheffield Michael Newman guitar record and I was shocked at how the Operas obscured many of the nuances of Michael's playing. The lack of note-to-note dynamics was perhaps the most obvious thing missing. I think Jim Smith from Avantgarde described it in his speaker brochure as lower-efficiency speakers being "deaf" to the small dynamic shifts. Although the Fritz are only about 95 db efficient as compared to the Avantgarde's 100+, I definitely hear what Jim was talking about.
In any case, I now see what this single-driver thing is about. Ok, they're not for everybody, but for someone who listens at moderate levels and with a front end that doesn't need to be hidden sonically, they are somewhat of an eye-opener. I can see how you people get hooked. BTW, if you don't know about them, you should check Fritz out.
http://www.fritzspeakers.com/FullRangeSpecs.htm
