750,1 to 1500.1 help

[vial 0]

so i upgraded from a zx750 to a zx1500 and i dont really notice a huge difference from the two im pushing two kicker cvx 12" at two ohms

my head unit goes from -15 to 0 to +15 db on the head unit and i dont really see a big difference from the new amp i usly keep the head unit set around + 11 i was thinking if i doubled my amp size i would go from only having my head unit set to around + 4-5 to get the same out of a + 11 db setting on a zx750.1 is it just my electrical thats keeping my system back ? am i missing something i mean my side mirriors viberae the same but i was thinking i would get a huge difference in sound going from 750.1 pushing two CVX's to going to a 1500.1 pushing the same subs.

sorry if i sound a lil sketchy im kinda been drinking CHEERS or is it just my electrical thats holding me back ? i mean its a stock 09 F150 so i havent upgraded big 3 yet.