This document discusses three key factors in selecting an appropriate amplifier power for loudspeakers: 1) A loudspeaker's power handling rating indicates its limit before damage, but does not correspond to the optimal amplifier size. 2) The appropriate amplifier size depends on required sound levels and audio signal types. As a rule of thumb, twice the loudspeaker's power rating allows reproduction of peaks. 3) Preventing loudspeaker damage depends more on proper system operation than on amplifier sizing alone.