actually as many of us know, overpowering a speaker wont blow it all the time. in fact, youre almost more likely to blow an underpowered speaker than an overpowered one. the reason is that a speaker doesnt blow because it gets too much power or plays too loud, it blows when it is being stretched beyond the means you provide it. when you start to get clipping from the speaker, THATS a bad sign. basically, if the speaker is trying to produce sound with sine waves that are at right angles, it will blow

hope i explained that clearly and properly, feel free to correct me guys!