@JoshMorr loaned me his ZMF Blackwoods for a while. I made measurements. I was curious how various bass plug configurations would affect bass response. Here's what I got: I included the FR of my modded HD650s since the ZMF tonality is so often compared to the 650s, and my Alpha Dogs since they use the same T50RP driver as the ZMFs. Subjectively, I know the greater bass extension of the T50RP-based headphones "should" sound better, but to me the 650's have better bass. It's just more fun with that nice midbass hump. As per el-Marvarino's practice, I use some felt strips (http://dsh.re/f5cf6) between the headphone pad and the measurement rig coupler to simulate an imperfect seal like eyeglasses, rad 60's hippie hair, and the like would create. Also on the subjective tip, the T50RP mods have a sort of nasty, rough, bright character in the upper midrange and lower treble that makes a lot of music less enjoyable to me. I believe that comes from the pretty intense distortion that seems to be baked into the T50RP driver: ZMFb distortion Alpha Dog distortion HD650 Distortion for comparison The Blackwoods are nicely tuned, but to me they don't sound as good as you'd think if you only looked at the measurements. Which is a shame; they're a lovely headphone in many other ways.