Interesting...Just found this info on Klipsch's website:
While Klipsch speakers are highly efficient and don't need a whole lot of power to drive them, you still need to purchase an amplifier/receiver that's relevant to the system you choose. After all, one of the most common causes of speaker damage is not having the right electronics to support it.
A good rule of thumb when trying to pair your speakers up with the right amplifier is to buy at least as much power as your speakers are rated to handle. For example, if a speaker is rated at 75 watts maximum power, then you should buy an amplifier that can deliver at least 75 watts per channel. However, you don't need to limit yourself. You can buy a 100-watt per channel amplifier for a 75-watt speaker because more speaker failure occurs from being under powered rather than over powered. It is safer to go slightly higher with your amplifier wattage because you'll never be in danger of clipping.
When an amplifier is expected to deliver more current to a speaker than it's capable of doing, clipping occurs. When an amplifier clips, it literally cuts off the tops and bottoms of the sound waveforms that it's trying to produce. This, in turn, sends a lot of distortion into your speakers, which is bad. Distortion puts a lot of stress on your speakers, typically the tweeter, and will eventually cause them to fail. In fact, your speakers will fail before your amplifier does.
So, according to that, I need to find a receiver that delivers at least 150w per channel up front and 75w per channel to the rear. Ugh, this is gonna cost more than I expected.