Your 41HZ data is incorrect. But tell me? Do you not expect there to be dynamics in sound? Are you trying to tune out dynamic pieces so that everything plays within the same 1-2 dB range? Music is a lot different than running a tone generator through your system from 20-20KHZ at at constant decibel level and looking at the graph for peaks and valleys built into the crossover network and then trying to correct it.
But yes! By all means, add 2 subs to your space. Everyone should, whether they know it or not.