[snip, emphasis added]
As for flat being preferred, yes it turned out that in this limited study that was more or less the case, although the Audeze is not really flat (you are in fact saying it is DF). That fact and the limited scope of our first set of tests, would not allow us to say that "flat is preferred". We were only speaking of the six headphones we studied. We are currently working on a new test, and so far, the "flat" (that is, equalized absolutely flat at DRP) headphone is NOT likely to be preferred over the other eq's we are investigating. As Sean said, "Stay Tuned"!!
I guess the thing I was wondering about "why not use same headphone + EQ to remove other confounding variables?" has been answered. I'll stay tuned, thanks!
Correct frequency response curve aside, do you have any thoughts regarding crossfeed or more sophisticated compensation for playing back stereo recordings on headphones, to simulate L speaker -> R ear (and R speaker -> L ear) transfer function?