I'm very happy with my single-driver Omega Super 3i Monitors. Fantastic speakers at their price-point. Efficiency is 94.5 dB at 8 ohms and they're mated right now with an inexpensive Chi-fi (3.5 wpc) SET integrated. A Decware SE84UFO (2 wpc) is in my immediate future.
high-efficiency loudspeakers
What is the best high-efficiancy loudspeakers? If you have it, are you happy ?