The D2K's I find sound better when driven with an amp -> currently using the ZO2 - epic amounts of bass.
Now in terms of loose or not.
Used J$ pads or angle pads.
But angle pads are $100
And J$....well good luck finding a pair (its been around a month i've had a thread open fro a WTB)
Long story short, if you, like me, don't want to "waste" $100 i suggest looking into the beyerdynamic headband snap on.
It will add extra padding at top -> more comfortable, but also should, in theory provide a better clamp.
I might get one of those snap-ons and report back.
Needs to be a little stretched when fitting on though
Additionally, you could stuff the stock pads, as described here: http://www.head-fi.org/t/299627/how-to-build-one-of-the-worlds-finest-dynamic-headphones-markl-denon-ah-d5000-mods
and emulate J$ or angle pads. It's a fairly easy mod to do, and reversible.