blending Magnepan MMG with SVS subwoofer

I'd start by measuring the response curve of the MMGs in your room. You can get fancy tools for this or use a free app like Octave RTA on a tablet, put the tablet in your listening position and run a frequency sweep to see where the MMGs start to fall off. 

Then set the low pass on the sub to match and dial it in from there by ear. 

Why do you have the sub on the side wall? Even if you achieve flat frequency integration the wave front is going to be seriously out of sync, and you may have nodes in the room that you can't solve through adjusting the power and frequency of the amp.

I would center the sub between the left and right channels to start. Room nuances will dictate final positioning. 

I have the 1.7s and went from one sealed sub to two ported subs and finally am now using two open baffle subs (home brew). Having a dipole that couples to the room similarly to the panel was a revelation. Also, for me, trading excursion for surface area was the largest step forward in musicality of the lowest registers. 

I don't know how much of an analog the 1.7s are to the MMG, but my subs are crossed fairly low, 88hz. 

I've successfully integrated MMGs with both Rythmik and Velodyne subs using Audyssey.  It's amazingly effective and virtually idiot-proof, but I understand that it's not everyone's philosophical cup of tea.  If that doesn't appeal to you, I'd suggest that you try to find a Velodyne SMS-1 sub controller.  (They were roughly $400 new, so hopefully you can find a used one that's not too expensive.).  This is a much more cumbersome set-up procedure than is Audyssey, but - once dialed in - it works extremely well.  It will take some time, but IME - if you invest that time - you will very likely get essentially perfect integration from an SMS-1.

bgoeller--Right you are! OB/Dipole is the ultimate sub for use with planar speakers. Anyone seriously interested can read about a particularly good one (featuring the Rythmik Direct Servo feedback system and dedicated 12" woofers used in opposing pairs) can read all about it on the Audiocircle GR Research Forum.

Just got the sb1000 myself, paired to my regas.  I feed the regas straight out of my integrated like i have always done, and I connected the svs to the pre-amp output.  Therefore, the regas play full range, with the svs sitting a few inches from the right speaker.  I wanted to get my stereo to sound warmer, closer to my pair of sennheiser hd-598, and add an octave.
So i started with the svs volume set at the middle, filter set @50hz, phase 0.
Over a period of a month, i raised the filter to around 90hz, and raised the volume sligtly to close to 1 pm.  I have the sound that i want, but omni-directional or not, you really need 2 subs to fully fill the room... Therefore, i m saving for another one.... Just my experience....  I would play the mmgs full range, with svs coming into play anywhere more or less forcefully between 80 and 50hz.

Thanks everyone for your responses,i have been playing around with the placement of the sub & that is getting me very close to where i want to be,with the Maggies running full range & the sub running off my preamp outs on my amp,volume is about 1/2 way up & crossover is at about 60 hz.Adding another sub as was suggested would probably also help blend things better,but for now i am just trying to get the best sound out of what i have in this small room.