Just one more tidbit: why do underpowered amps potentially damage speakers? The reason, as previous posters pointed out, is that they are more likely to go into clipping in the listener's quest for louder sound. Nearly all of the power in a music signal is in the bass and low midrange. When the signal is clipped, this distortion generates an abnormally high proportion of power at high frequencies. So even though the total signal power can't increase (the amp is clipping because it's reached maximum output power), more and more of the power is appearing in the high end of the frequency spectrum. That's part of why it sounds so bad. Plus, it's this abnormally high power in the upper midrange and treble pouring into the tweeter that burns it out. The voice coil in the tweeter is sized for "normal" amounts of power in the treble range. Clipping causes abnormally high levels of power in the treble range, overheating the tweeter voice coil and causing it to fail. Next to go is the midrange speaker's voice coil. It's beefier than the tweeter, but still relatively wimpy compared to a woofer voice coil.
Bottom line: I agree with previous posters and would not worry about hooking up 75 W amps to speakers with a labeled rating of 25 W. I would be cautious, though, and start with the volume turned ALL the way down, and cautiously raise it, listening to see how the speakers react. At the first hint of distortion, back the volume down IMMEDIATELY.
Bottom line: I agree with previous posters and would not worry about hooking up 75 W amps to speakers with a labeled rating of 25 W. I would be cautious, though, and start with the volume turned ALL the way down, and cautiously raise it, listening to see how the speakers react. At the first hint of distortion, back the volume down IMMEDIATELY.