It would only maintain the 94dB sensitivity if the baffle width remains the same.
If you separated them, and used a narrow baffle on the MTM section, you will only get about 90.5dB sensitivity. (see the X-CS Bravo which uses the same drivers)
The 12" subwoofer has it's own amplifier, but you can run jumpers from the speaker inputs to the high-level inputs of the amp, or you can use the low-level RCA inputs.