I agree with Hasse. Experienced the same buzzing due to loose bass coils. Call Magnepan, they will repair your speaker at no cost to you ( shipping is also free.)
Magnepan 3.5R buzzing
I have a 2 year old pair of Maggie 3.5R's and recently when playing some music which contains low bass the one speaker's top mid-bass panel plays the music but there is a buzzing along with the music. Has anyone had this problem, is there a quick fix thatI can perform w/o having to send back to Magnepan?