Downgrading

I have 2 12 ported champions not sure exact model. Going to p3d4 rockford 10 in a sealed box. Using the same amp which is 400.1 rockford. Considering the 12s were crazy underpowered do you think ill get similar or better performance or volume? Never had a sealed woofer. Probably never had as nice of a woofer that the p3d4 claims to be online.