Playing with two sets of speakers simultaneoulsy

I know it's blasphemy but I have been playing around with adding a second pair of speakers and found it to my liking. Using the woofers only on my 1.6qr and sitting right next to my proac D30R's, I have found that the sound is fuller and more expansive, making orchestral music more live like.  Both speakers have their own power amp and volume control which allows me to play with different ratios though I find it best with Proac's as primary and the Maggie's just adding a little to the mid bass to be ideal. Imaging doesn't seem to be affected and the the speakers can still play loud with less demand. WAF is low but the Maggie's are easy to move. I guess it's an alternative to large full range speakers. 
Had a similar experience back in college in the 1970's. Me and my roommate both had unusually good systems for the day, and running both together was the best.  

Didn't know it then, but now I do, that a lot of this was due to the fact that multiple drivers in different locations is by far the best way to get good bass response. Notice that is what you are hearing too. 50 years, physics hasn't changed. Not one bit. 

Which is why, when you advance from lamp cord and freebie rubber power cords, low-res stuff in general, and learn to set things up better, then you will notice those multiple speakers really are messing with your imaging. Because: physics. Still hasn't changed.
In the case you just described, using the Maggies as a woofer, you have made your own loudspeaker system. You might want to try a measurement to see what you have at the crossover point. But a general note of caution, if you were playing two full range speakers together the lessor speaker pulls your system down, the better speaker doesn't fix that. 
How far away are the Magnepans and the Proacs from your listening position? 
About 12 ft. Speakers about 10 ft apart from center to center roughly. Why do you ask?
About 12 ft. Speakers about 10 ft apart from center to center roughly. Why do you ask?
Sorry, I can’t remember now what I was thinking when I asked that. In any case I agree with raysmtb1 - more drivers more fun. The Maggies have some advantages in the range you are using them to complement the Proacs. It’d be interesting to see a frequency response plot at your listening position. I’m guessing it might be better than you’d get with just the Proacs running by themselves.
Yes, I do like the sound with the Maggie's especially with orchestral music. Don't know how to measure frequency response though. The far distance to the listening position allow the two speakers to act like one and not affect imaging while providing a more expansive soundstage. I've added a little subwoofer as well to provide even more impact. 
You have made a hybrid type of speaker system. It’s fun to do so occasionally, but it will exhibit serious drawbacks, as all such cobbled together systems do. Once you get past the novelty of it, and go back to listening to the proper speakers, you will hear elements of the sound quality that will be more to your liking with each of them. That is not to suggest the hybrid setup is not very enjoyable in its own way. I can get a pretty good understanding of what you are hearing from it, as I have used both types of speakers a fair bit, and have done several alternative systems. Just recently I placed subs in an unusual location relative to the PureAudioProject Trio15 Horn 1 Speakers - which, BTW, I was using horizontally, in what I call Landscape Orientation! So, I get the idea of trying alternative rigs and experimenting. :)

The bass portion of the Maggie is serving as a quasi-subwoofer, so it’s no wonder that you feel it’s more grand sounding. You’re to be commended for your creativity; it is the sort of thing I would have done years ago to explore/experiment. Sometimes you find out some very interesting things when building alternative rigs. It can definitely help shape your preferences and assist in searching for your dream speaker.

One potential big benefit; you are perhaps discovering that you might prefer a hybrid speaker over a conventional dynamic or panel speaker. That is a worthwhile discovery, and if implemented properly, i.e. the right manufactured speaker, which should have ironed out wrinkles inherent in a rigged situation such as the two speakers pulled together, might be far more to your liking.