I own a pair of the LS-9’s, and three of the planer drivers on one speaker have stopped working (bottom three). I Ohm the wiring connections and they are good so that leaves the drivers. Since they are wired in Trio's I assume one or more of the three is dead. Since the GR website does not list these as being available I did a web search and found what I think are direct replacements but need verification. Parts Express has Bohlender Graebener Neo8S Planar Transducer and Bohlender Graebener Neo8-PDR Planar Transducer. Which if either would be a drop in?