I'm in an auditory perception lab at MIT, and we're looking for the most "objectively flat" headphones for doing experiments: that is, the headphones that by objective measurements have the flattest frequency response as measured at the eardrum. We also want to minimize any colorations like harmonic distortion. Today we measured the frequency response of my Senn HD650 using a silicone ear/ear canal and found a peak at 2-4khz, otherwise flat. It seems like the Denon AH-D2000 seem to be the way to go given the frequency responses as measured on headphones.com but I was wondering if anyone would have any advice on this. http://www.headphone.com/headphones/denon-ah-d2000.php#tabs Thanks!