I had the same experience with the M40s I bought them refurbished and received them today. My reference ones blow them out of the water in all aspects except looks. Reference ones are way louder and have better highs, mids, and lows. Also with the noise cancellation activated the sound becomes very distorted. I was wondering if it was because I bought them refurbed but reading your post makes me think otherwise. I contacted Klipsch to get their opinion. What did you end up doing in your situation?