magnepan experimenting

I accidentally switched my left and right panels of my mg12's today and found that there was too much bass. Is there any reason for this or is it all in my head

Are you sure the tweeters are both inside or outside ?
Maggies age,I had a pair where one was louder than the other
which might give you that if one was closer to sidewall.
No doubt you know Maggies are hyper-sensitive to placement,
I found within 1/8th of a inch equality for both speakers from surfaces. Coffee tables between you and speakers can do funny things as well.

The tweeters. Are on the inside and there is nothing between them and the couch.but there also seems to be s lingering effect on lower frequencies. I noted a couple of songs. I am going to listen to those again,switch speakers back and then play songs again