just a quick ?
 

i have a 12 inch Rf sub.. its the xlc series.... bout 2-3 years old im guessing. my ? is how many watts do i need to push this? 500-600?

rockfordfosgate.com has all of the manuals you need - I would look it up, then search for a amp that is about 100%-50% of the RMS rating on the sub. The closer to the RMS, generally the better - you can go over too.

Shooting from the hip, I'd guess it's about a 300W sub.