One Channel of Magnepan Mini Maggie sounds lower than the other

The mini maggies are dipoles and very sensitive to position.  Were the speakers they replaced also dipoles?  Is the proximity of the left and right channel mid/high panels to the walls similar (e.g., is one much closer to a wall or corner than the other)?  To check if placement might be a factor, keep all of the connections the same but switch the speakers left/right.  If the same side is still lower in volume then the imbalance is likely to be caused by speaker position.  Keep in mind also that the crossover point between the bass panel and the mid/high panels is relatively high so if the bass panel is sited more closely to one mid/high panel than the other that may also contribute to a perceived imbalance.  

Well I check the distance between speakers and walls and everything is symmetric. That is why I have no clue about this imbalance in sound from the mid/high frequency panels. 

Have you checked the tweeter fuse?

If you don't have a spare try swapping them from speaker to speaker.

Also remove and reinstall the tweeter bar/connector on the back of the problematic speaker.

DeKay

DeKay, I did change the fuse in the bad panel and to my surprise now both speakers play at the same level!!! Thank you very much for your help.

R.

Deox all your connection points on that speaker,or you will build up a form of resistance from oxidation of combined metals, Maggies did have a bad problem with the voice coils separating from the diaphragm and that i understand was because of the adhesive used, now i understand they have fixed the problem, i had a pair and sent them into get rebuilt and it cost me, when they came back they rattled so bad i gave them to Goodwill after waiting 6 weeks to come back home, now my Acoustats get all the love. and now with Covid 19 I love them more!!!