Thanks for the comparison. I love bass, but I love quality bass. I don't love bloated bass or bass that isn't in the recording. For example, in my home theater I have three pretty big subwoofers, but there's not calibrated above the other speakers just for the sake of more bass. They are there for when the movie calls for a lot of bass. When there's an explosion in the movie, I want my subs to move a ton of air and shake my house, but when someone closes a door in the movie, the subwoofers aren't cranked so high it sounds like an explosion. It should just sound like a door closing : ) It sounds like I would prefer the HM5 and it doesn't hurt that they are $100 less. I'm sure I would enjoy listening to the Denon and wouldn't dislike them, but I doubt I would think they are better,
brainwavz hm5 are neutral as many have said.
the bass shows up when it's in the recording and disappears otherwise.
however, if you listen to any kind of even mildly bass heavy music or are not used to the sound of flat/neutral speakers and headphones, the hm5's sound bass anemic.
the bass punch is there, but the subbass is not (quantity wise, not presence wise). in other words, if you listen to dubstep, you WILL want more out of them. unless you have an amazing amp.
anywayz. out of my want of moar bass. i got the d2ks. i'm happy. but in comparison, the bass of the d2ks are less punchy. it has mooooar subbass/bass quantity wise.
the mids of the d2ks sound recessed IN COMPARISON, not on its own. soundstage seems a tad bit bigger too.
sound leakage? the d2k's leak. while the hm5 only leak at high volume.
comfort? the d2k's basically rest on your head with a good seal. the hm5's feel tight yet comfortable. meaning. if you're doing some headbanging, the d2ks will fall off whereas the hm5's won't.
that's the quick gist from my view.
sorry for the wall of text.