And another point to keep in mind:
Everyone mistakenly focuses on the wattage rating of speakers. Speakers ALMOST NEVER fail because of exceeding their wattage rating - which simply tells you at approximately what wattage your voice coil will melt. I don't think I've ever heard of a single case on this forum or anywhere else where voice coil melting as being the problem.
Speakers fail because of overexcursion. "Upgrading" to a higher wattage rating is senseless. Its the xmax and xlim factors that you need to look at, not wattage rating.