It really depends on the amp. Most times, I would not expect the most powerful ones to work as well on flea-power amps. It isn't about efficiency 'cause they're all efficient. It's about the way very small amps can interact with their load. The Stage, Premium and Professional Series are all made to handle 600 watts RMS and up, so they're not my first pick for very small amps.Having said that, I've connected these powerful π speakers to some flea-power SET amps and had them surprise me. Not all amps work well with them, but they use the most expensive premium components so it's worth trying them. We're soon to announce a line that uses Eminence Magnums, and that is another high quality option to look into.