200 or 300 watts of clean power will not damage your speakers. 15 watts of distortion can shread them. Your amp is only going to deliver its rated output for very short intervals (milliseconds). It simply has plenty in reserve to keep it from clipping. this being said, it is not good for your speakers to be played at volume levels that hurt your ears (and its not good for your ears either).
also keep in mind that surround speakers are limmited in the frequncies they are asked to reproduce (sound guys who do the soundtrack for DVD's know you have smaller surrounds) and how often they are asked to make sound (they are not screaming throughout the movie).
also keep in mind that surround speakers are limmited in the frequncies they are asked to reproduce (sound guys who do the soundtrack for DVD's know you have smaller surrounds) and how often they are asked to make sound (they are not screaming throughout the movie).