I have the hd595's and my friend has the shr940's, he has since gotten into speakers and has loaned me the shr940's. they are no way near as clear as the hd595''s IMO. i have not heard the hd800 but i can only imagine that the shr940's pale in comparison to them in every department.
You didn't hear the hd800 with (fast) metal. There's at least mike that agree with me that the srh940 are better for metal. If you look at objective measurements from innerfidelity, the impulse response of hd595 is a mess. I've never a heard headphone slower than hd595, but I enjoy it with some musics.
The srh940 sounded catastrophic with a bad source, and bad positioning. I liked better my ksc75, when both plugged on my onboard realtek soundcard. This is an already different story when using a xonar stx (very crisp , detailed treble) ,. And if you play with position of headphone on head you can have more bass, and less aggressive treble. I didn't hear the srh840.
Edited by extrabigmehdi - 6/17/13 at 6:30am