Type R's
 

k ,i have 2 12 " 2 ohm type r's in a sealed box, and a kenwood kac 728s 600 watt max 2 channel. I know im way under powering them cause 600 watts is 300 rms dived into two, it only give you 150 watts rms for each sub. But honestly it still pounds hard. What would be an upgrade for the amp and box?

Budget for the amp and can you build a box or would you need one shipped in?

you wanna look for something that does around 1000rms @ 2 ohms. make sure you have the electrical to back that power up.

suggested amps would be:
alpine mrp-m1000
kicker zx1000.1
hifonics bxi 2010d
infinity ref1211a
soundstream pcx1500d

Alpine MRP-1000.

A friend has this setup in his car and its LOUD. Just make sure you have the proper wire to power it and a box correctly sized for these subs. They are monster subs and need big power.