Summary: These speakers are very efficient and can be driven with a 20 watt amp. The reason they're so efficient is the horn mid-range and tweeter. They sound like they're shouting at you. The bass is ill defined and I just could not get these speakers to sound good. I'd keep looking. Maybe it's just me, but I just do not like the sound of Klipsch speakers. From Klipschhorns to La Scallas, the horn loaded system just does nothing for me and I've been an audiophile for 35 years.
Summary: I had a pair years ago, sounded great and built like a tank with Birch Plywood, Just got a pair and they are half the speaker they used to be, i.e. they still sound great, but they are built like crap using MDF and glue guns. Save your money and buy a speaker from a company that cares about build quality as much as they do sound.