The Upper 2/3 of Edgarhorn Titan system could be considered bookshelf-sized, practically. That would leave finding room for the 80hz or so bass unit(s) somewhere else in the room. Efficiency would be in the 105+ range at least. To get that small and that efficient likely requires either compression driver(s) or Lowther/Fostex type single driver speakers, but you give up bass.
-Ed
-Ed