It's not that simple... for example what is slope of the subwoofer and what's slope of the Gem2 crossover? The steeper the slope the quicker it rolls off... And what is the -dB at 75Hz? -3dB, -6dB, -12dB? Makes a huge difference...
I bet you'll be fine integrating the Gem2's with a good quality subwoofer
I bet you'll be fine integrating the Gem2's with a good quality subwoofer