Check out this speaker kit call C-Notes. They're really well rated and a pretty simple/budget friendly option, especially if you're okay applying some eq on them. Paul Carmody has many good designs.
With passive speakers, I agree, but with active/DSP speakers you can do ludicrous things. There's this build on diyaudio called something like "compact active 3 way", that'll give you an idea of how decently powerful a small speaker can go (and that's despite some design flaws in the build like the choice of a passive radiator).
