New subs not hitting hard need help
 

Ok so I have a vented duel 12" speaker box that the speakers face towards the floor of my crew cab Chevy 1500. Running a power acustik RZR2300D two channel amp "one neg and one pos". Had the older Sony xplod red otogan shaped 1200 watt 12" subs they knocked hard and sounded good but wanted to replace subs with new ones and I bought two pioneer TS-W304 12" subs. When I hooked them up they barely made my rearview mirror shake. What would cause them not to hit nowhere near as hard as the old sonys? I've since put my old sonys back in wired the same way as new pioneers and I'm back to shaking my whole truck again. Can anyone explain this? Thanks in advance for information.