Nearly all the speakers mentioned in this thread are active (Neuman KH120, Adam F7, JBL LSR 305/308/705p/708p, Paradigm Active 20/40, and my single driver speakers/Dynaudio BM5 MkIII) or "active ready" (Bryston - crossover/amps are external and sold separately). All of these are active meaning that the speaker uses a low power crossover with one channel of amplification per driver. DSP is available in active design but certainly is not a requirement.
You would probably be surprised to find out how big of space a small speaker can fill. Keep in mind that near-field listening is preferred by most professionals because it minimizes room interactions and deep bass is best reproduced in-room with separately located multiple subwoofers. And if not satisfied with the above examples Neuman offers 3-way active mid-field monitors, Adam offers many larger active speaker as do JBL, Dynaudio, and many others. The British seem to have developed a niche for in-room active listening from brands such as ATC, Meridian, and PMC, but don't forget Linkwitz and Von Schweikert from our shores. Don't know if the Klipsch speakers you linked are active or simply powered (combined amp/high voltage crossover).
"Active ready" designs like Bryston or Linkwitz give the owner the flexibility to purchase their own crossovers/amps and keep those components away from the speaker vibrations but add cost, bulk, interconnects/speaker cables/power cords, and most importantly the unknowns of amp/driver synergistic reactions. The main audiophile objection to active (or powered) speakers is the loss of not being able to select the amp. Studio professionals (the guys recording, mixing, and mastering your music) almost universally prefer active design and have no problem with allowing the speaker designer to select the amp and putting it inside the speaker cabinet.
Note that nearly all subwoofers are active designs.