I'v'e been using a Velodyne 1012 (or 1210), ferget which it is for about 6 years now in a 2 channel system. with a pair of 1.6's The way I implement it is a little unusual.
Since the MAggies are polite enough to simply ignore what they cannot reproduce, IK run them full range. I take the preamp out and spilit it with one side going to a Rotel RB-991 for the maggies and the other side to the Velo.
I have the low pass filter on the sub to somewhere around 45 - 50 hz so that I can use the maggies to their maximum range and only use the sub to fill in where they start to peter out. FWIW, I have the sub placed near the right channel, on the adjacent (well, 4 feet) wall. YMMV