As long as you aren't raising the average heat to the coil over a specific time frame you're ok. If your speaker design is able to cool the coil efficiently you're fine. What you should be worried about with more power is mechanical failure...i.e. exceeding excursion limits. Box calculators can help you figure that one out.
Short answer...it's not likely you'll damage anything. Only way to be certain is to start reading about speakers and box designs. Oh yeah...your gain. That's the other #1 cause for speaker failure. Try to dial it in correctly. Go to JL Audio's website look through technical to find out how to set your gains using a digital multimeter.
