Maggie resisters

How does inserting resisters in the mid and/or tweeter feeds in Magnepans, specifically 3.7s, impact the impedance load the amp sees?

Not sure I need the additional power, but I have been playing around with my new speakers and bridged my amps. Although the 2 AR D400s are. hefty, they seems to get a bit thin and a little grainy with the resisters are used and I though it might be from the addition 1.5 and .5 ohm resisters I was experimenting with. The Maggie's pretty much are a 2 ohm load to the bridged amps to begin with and with no resisters it seems to drive them fine with no signs of strain.
BTW I don't think it is the resisters themselves or the sound difference they create because using them with sgl amp in stereo sounds fine but obviously I have less power available.

Actually talked to tech guy at Magnepan today and was told that the resisters actually make it easier for amp to drive because it raises the ohms a bit which surprised me.

Perhaps what I am hearing is additional noise of the bridged amps when played at very loud levels, or the fact I used different speaker cables when I ran them bridged, but not sure.

The playing around with it is 1/2 the fun.