Ah. Your first post does not say a pair.

If you have a pair of 12s on what you believe to be 500watts and it's not shaking your fillings then you need a better enclosure. Potentially changing to a single 15 in the same space may net more output.

 

Switch up the sub for a 10 or 12 w7. They sound great and with that amp you should be able to power one easily. Ps they hit hard if the settings are right

 

I would agree with that if you can get a really good deal on a w7, but you can get other stuff that is comparable for less than half the price. A friend of mine has a 12w7 in his car and they do sound good and get somewhat loud. They are however 3 ohm speakers, which means your amp will only give it 5-600 watts, so probably not much louder than what you have now.

 

Man it's sound like boom boom...