2) On http://www.headphone.com/ , find any headphone that shows a graph on it's page, then click on the graph. You will be able to change which headphone is graphed and add others for more direct comparisons.
3) Then there is Golden Ears. I have trouble searching his site directly, so a google search with the headphone model and site name will generally show it if the review is there. For example, https://www.google.com/search?q=golden+ears+ath-a900x&rlz=1C1CHFX_enUS516US516&oq=golden+ears+ath-a900x
Keep in mind that headphone frequency response measurements don't always translate to exactly how you will hear them. Individual fit and placement can affect the response a little. See the measurements more as rough guides rather than something that can be compared very closely, hz to hz and db to db.
Thanks again for the quick reply.
I was just curious to see what my previous headphones 'behaved' like, it totally makes sense that the actual perceived sound would be different than its actual curve.
I'm going to look into the return policy on digbuy - because I don't think I have any retail stores in my area that would allow me to preview them. If it looks like they have a flexible return policy I'll go ahead and make the purchase on them (curious how they'll fit). I'll need a sound card to make the most of them, I'm thinking the PCIE one that was mentioned earlier in this thread. (Xonar DXG?). I believe that card has amplification built in which is perfect considering these headphones would be exclusively used with my computer.
Xonar DXG + A900X
Is there anything else I'd want to consider? I'll buy the mic when its all said and done.