Get two additional small subs to work with the ML sub. Allows for symmetry both visually and acoustically. Two Epik Legends or two VTF- MK 4's for example, would be a pretty economical purchase and would sound absolutely fantastic.
I've tried quite a few different sub positions/configurations, and I must say that 3 subs (2 smaller subs handling front soundstage and larger sub placed nearfield handling 50hz and under) is my personal favorite. as always, ymmv
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