Those amps are too big!

Playing off yesterday's post that the speakers in Music Room One were too big for the room, and the often misunderstood idea that physically large speakers must need lots of power, my friend Jim Anderson, formerly with Wadia, reminded me of another misconception. Power amps can be too big for some speakers. It's a natural thing to believe that a small set of speakers rated at 100 watts might be in danger connected to a 300 watt amplifier. But truth is, the biggest danger just might be the opposite. The vast majority of tweeter damage comes not from too much power from a big amp, but rather hard clipping from too small an amp. Speakers are generally rated by their efficiency relative to a single watt. You've seen the magazines refer to it. 90dB, 1 meter, 1 watt. And what that means is the speaker will produce 90dB of sound if you place 1 watt at its input and stand 1 meter away. So naturally, if you connect more watts than can be used by the speaker there might be a danger. Only, watts don't come out of power amps without being commanded to do so by the preamplifier, which acts as a sort of valve regulating the loudness of the speaker. Just as you don't worry about the thousands of pounds of water pressure held back by the valve regulating flow to your home, you shouldn't worry about too big of an amp powering your speakers.