input sensitivity question

how do i know if a particular amp's hi-level inputs can handle the output from my factory amplifier?

for example, if my factory amp is putting out 25x4 rms at a running voltage of 13.6 and i want to create a subwoofer signal from the two rear door channels and send that into an Alpine MRX-V55, which has input specs as follows:

Input Sensitivity (RCA Input): 0.1 - 4.0 V
Input Sensitivity (Speaker Level Input): 0.5 - 10 V
Input Impedance: >10k ohms

is there some kind of limit on the voltage to the speaker level inputs?

i guess maybe i am asking if 25w rms exceeds the 10v input sensitivity. How do you calculate that?

thanks!