oldjazzer...The D-18 must be unreal...pre-war D-18's are the finest acoustic guitars I've played. Wad the effect of the 8 guitars obvious, buzzing or sympathetic resonance, or was it more subtle? My culprits, if they are messing with me at all, are a 97 D -42, a 69 O 16NY, and a Collings OM2H.