That icon is one of the better subs out there snd if it’s not cutting it then putting a different sub in running the same power is just a waste of money
If you want it to hit harder your going to have to spent the money to upgrade both the amp and tge sub or add a sub (as long as it’s the same sub and even then the age difference between the two)
Do it right the first time and it will save you money
2 new subs, SA’s or Icons and a appropriate amp like a CAB 22
Might be cheaper and take up less room to just go with one 12 rated at 2000-2500 watts