Well since I now like these enough for them to be keepers, I decided to do a little experimenting. There are quiet a few things I like about these cans. They're not as boomy as the d2000/5000, have a nice treble sparkle, and sounds a bit cleaner to my ears. This is all while actually having the isolation of what a closed can should have. I also like the cables and iPhone control(including Siri). But there are a few things I would like for them to do better. Though the bass is less boomy, it's still a little boomy compared to my high end cans. And the mids are still a little recessed. So I would like just a little better balance and coherency.
The first mod I tried I liked so much, I decided to leave it at that. I really didn't want to mess with dynamat because its so messy, it would be too much trouble to remove it If I didn't like the affect. So the mod I tried was to simply stuff the cups with a decent amount of fiberloft. What this did was to significantly tighten up the bass which in effect brought the mids forward. I don't really think the quantity of mids increased but more so the bass getting out of the way made them come through more. The soundstage is also deeper with the treble being a bit less splashy. The sound as a whole is more balanced and coherent. The treble seems to have a touch more sparkle with more air around the instruments. They also have a bit more clarity.
All of this did come with a trade off though. The bass looses a little energy, but is still just a little more than neutral. But the extension is still there. So you loose a little of the fun factor with gaining a more of a reference sound. How much fiberloft you use is up to the individual to play around with. The sound as a whole is also less grainy as well. And it's so easy to do, only takes 10 minutes tops.