Thiel CS 3.6 mid-range problem

I have a pair of Thiel 3.6's, with a Mark Levinson No. 336 amp plus Levinson pre-amp and cd processor. I also have Audience AU24 "e" cables and AR6T conditioner. My mid-ranges are blowing out frequently -- 3 times this year. This didn't happen until I got my Audience conditioner and cables. The volume dial of my pre-amp is actually set lower than where it was prior to installing the Audience equipment. I don't think this is a case of playing the system too loudly. Time to upgrade speakers? Anyone have a solution or an idea?