I can't search yet

but am considering trying one or both of these paths for my speakers. Wondering if it is advisable to leave the existing XO in place and just send the lows directly to my subs. Leaving the signal above 50-100hz to the Maggies. I don't yet have an understanding of how the factory XO is setup and feel like I need to understand how the larger portion of the panel is crossed. If it isn't advisable to keep the factory XO then I might go with a 3 way...
My setup includes a Mac Tube PreAmp and 2-1400watt into 4 ohm mono blocks. My subs are Paradigm Seismic 110's
Hoping someone has ventured down this patch and is willing to share any experiences and tips. I know the "MiniDsp" probably isn't going to get any love but I'm interested in comparing it to the XM44 just out of curiosity.
Thanks
Dennis