What size CAPACITOR would i need for two 15" Rockford Fosgate T115D4 subwoofers w/ a Kenwood KAC X14 amplifier

the amplifier max outage is 2400 watts, the RMS is 600 @ 4ohms. the speakers are max 1200 watts each. i dont know anything about capacitors or why i should use them so any information would be highly appreciated. Please no idiots saying "i dont know" or "just call" etc... desperation for answering points is pathetic!!! leave the answers to the experienced people please!!!