rear speakers popping/cracking - defective?

Since day 1 of having my car (07) the rear speakers have had an issue handling songs with alot of bass. After a certain volume level they just start to crack/pop.

I've tried to document this with a video, unfortunately the iPhone is terrible at picking up lower frequencies but this should give you an idea:

YouTube - 2007 Acura TSX rear speakers popping/cracking problem

Are they defective? Or is this inherent with all stock speakers? I'm willing to upgrade but i'd like to pinpoint if its worth bringing it to the dealer for. I'm at 70k on an 07 so they'll probably just show me the door but this has been happening since Day 1. Fortunately i don't listen to every song at such volumes but it is quite annoying when it does occur.