I can see what mouth is saying, but he didn't convey it right.
10K watts at some point would cause harm to a 500w speaker, for the most part you can give a speaker 2x the power it's rated for and you'll be good, but at some point the power will start to push the speaker to it's mechanical limits, at 20x the power, gains set properly, and 0 distortion, the speaker will start to fail. Speakers have a rating for a reason, for the most part they're rated a bit low because the company doesn't want to have to warranty dumba$$'s who don't know what they're doing.
Distortion is the number one cause of speaker failure, you can give a speaker more power and it operate safely, but WITHIN REASON! 10k watts to a 500w speaker IS NOT within reason.