you can't bridge a 1 channel amp...and the 250M is a monoblock. Those amps are called monoblocks and are usually only for subs. You can bridge a 2 channel amp into 1 channel and a 4 channel amp into 2 channels. You just have to watch what impedance you are running, as most amps are 2 ohm stable, meaning you can bridge a 4ohm load. If you have a one channel amp that is 2ohm stable (in which the 250M is), in order to get the most out of it you should get a 4ohm dual voice coil sub and wire the coils in parallel (2ohm) and then wire it to the amp.
Go
HERE, it will show you how to wire them up the way I described. Just input the number of subs you have and what version of voice coils you have (dual 2ohm or dual 4 ohm). Just remember with that amp you want a 2ohm load, NO LESS! You can go to a 4ohm load but then your power will just about drop in half.
Paul