Just for fun, using Jude's measurement (and assuming he didn't do anything weird in the measurement process), I made a prediction regarding Empyrean's "sbaf-compensated" FR. Of course you may need a grain of caution and salt! HD800 fr data were from my own measurement -- averaged from 6 sets of measurements. Didn't do anything for 200-4k hz. Anyway, predicted fr looks very impressive, as it should be for 3k headphones.