Hello ahrgef! High effeciency speakers are excellent choices for low watt amps. Zu Audio makes several models. Many DIY designs are very efficient ad inexpensive to build. You can build a pair of 110 db sensivity speakers for under $500. Look for high speaker impedence as a clue. 16 ohm speakers are usually high efficiency. It's "old school" from an era when talking movies were new and all amps were 20 watts or less. A speaker that requires a "high current" amp is usually low impedence and not very efficient (sub 85 db sensitivity). Magnepan speakers are a good example. I have a pair of LRS currently, will order a new pair of LRS+ soon, and have owned two other models (MGII, 1,7i) in the past. Wonderful sound, but needs an amp that can "push." My 9 wpc 300B tube amp coaxes wonderful sound from some DIY 110 db sensitive speakers. There is very little difference in the sound of those two systems. Happy Listening!