Also remember its better to have a amp that is too powerful than a speaker that draws more than your amp can produce. Theres a myth that you should pick speakers that are rated for more power than your amp can produce, but in fact its the opposite. If your amp isn't powerful enough it will clip the signal and generate heat (which will cause it to fail prematurely). The signal clipping will damage your subwoofer and it will sound bad.
For example: 500 watt rms rated subwoofer should be mated to a 500 to 1000+ watt rms amplifier, not the opposite.
My home audio system is a set of 100 watt rated Infinity Reference Series monitors (6 ohm) on a 900 watt RMS x 2 channel (rated at 4 ohm) pro audio amplifier. This sounds a lot better than a 100 watt receiver because it has more headroom (more wattage allows for more dynamic peaks in music), the same is true for car audio. Matching rated RMS on the amp to rated RMS on the speakers is not always a good idea, in fact its better to have more RMS on the amp and turn down your gain (level matching).
Excess power does not blow speakers, distortion/clipping blows speakers. If you ran so much power to blow your speaker you would be blowing your ear drums.
2006 Mustang GT Premium 5MT
C&L Street Intake
DiabloSport Predator 303whp 310wtq (JPC 93 Octane Dyno Tune)
4.10 FRPP Gears
GT500 Strut Brace