By cuppy/wonky I mean a bit more nasal sounding and with reduced soundstage vs stock, the EQ that works fine on your pair seems to make mine worse, so it seems that unit to unit variation can be pretty large.
I you like the HD600 minus the soundstage, and are willing to spend quite a bit more (clearly entering diminishing returns territory), the HD800S is the answer (when EQed). All things stock, for me the HD600 sounds more correct than the HD800S, and certainly have a higher performance/price ratio.
Anyway the K702 are by no means bad headphones, I can understand why some people may prefer them to, for example the HD600, but for me they present two main problems, they are less natural sounding than the Sennheisers, much less at stock, it can be partially corrected by EQing them, and less comfortable (for me at least, mainly at the top of the head, and my unit doesn't have bumps in the headband).
I you like the HD600 minus the soundstage, and are willing to spend quite a bit more (clearly entering diminishing returns territory), the HD800S is the answer (when EQed). All things stock, for me the HD600 sounds more correct than the HD800S, and certainly have a higher performance/price ratio.
Anyway the K702 are by no means bad headphones, I can understand why some people may prefer them to, for example the HD600, but for me they present two main problems, they are less natural sounding than the Sennheisers, much less at stock, it can be partially corrected by EQing them, and less comfortable (for me at least, mainly at the top of the head, and my unit doesn't have bumps in the headband).
What's cuppy? There does seem to be a fair bit of variation based on my 2 units measured, so you might be right that your K702 is a way off from my 2 units, you could always send it to Oratory I guess.
I've never been able to make the HD600 sound spacious or wide, even with an optimised frequency response that I identified as enhancing spatial qualities of headphones for myself.....even with Soundblaster Virtual Surround Sound 7.1 the HD600 doesn't present a very good 3D sound scene in gaming, so I find it surprising you say you can improve the soundstage of the HD600. I think the only way to improve the soundstage of the HD600 would be to use in-ear mics and go through the Impulcifier project or Smyth Realiser. Most people find the HD600 series to be narrow in soundstage so I'm not alone in that experience.