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. 
jaferd
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?