We need sub impedance for each coil to help.
If its 2ohm per coil then it'll work the way you want it to. If they are 4ohm coils on the subs, you're going to get 4 ohm load unless your amp is 1ohm stable.
For 2ohm/coil subs: Wiring the sub coils in series, that is the (+) from coil #1 to the (-) of the coil #2 on the same sub will give you an 4ohm load. Do this for both subs. Wire the remainder terminals in parallel, (-) on sub #1 to (-) on sub #2 to (-) on amp. Repeat for (+). That will result in 2ohm overall load and "500W" per sub
For 4ohm/coil subs: Wiring the sub coils in series, that is the (+) from coil #1 to the (-) of the coil #2 on the same sub will give you an 8ohm load. Do this for both subs. Wire the remainder terminals in parallel, (-) on sub #1 to (-) on sub #2 to (-) on amp. Repeat for (+). That will result in 4ohm overall load and "250W" per sub