Yo Audiableguy, I had a pair of MGIIIa's that buzzed. I sold them. To fix your speakers, you will need to ship them back to Magnapan for new socks. It will bring them back to "new" condition. The problem is that when played at high volume levels (expecially with power amps that cannont handle the transients and clip) the DC will overheat grid (wires)on the sock and deform an area of it. This area will be "loose" compared to the rest of the panel and it will show up as a buzzing noise during certain bass passages. As for the Apogees, the ribbons can usually be re-tensioned if not damaged. More info is available at http://audioworld.com/cgibin/sw/Ultimate.cgi which is the Apogee users web site.
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?